ADRF6510 (Rev. B) - Analog Devices

32
30 MHz Dual Programmable Filters and Variable Gain Amplifiers Data Sheet ADRF6510 Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 ©2010-2017 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com FEATURES Matched pair of programmable filters and VGAs Continuous gain control range: −5 dB to +45 dB 6-pole filter 1 MHz to 30 MHz in 1 MHz steps, 0.5 dB corner frequency SPI programmable 6 dB front-end gain step IMD3: >55 dBc for 1.5 V p-p composite output HD2, HD3: >60 dBc for 1.5 V p-p output Differential input and output Adjustable output common-mode voltage Optional dc output offset correction Power-down feature Single 5 V supply operation APPLICATIONS Baseband I/Q receivers Diversity receivers ADC drivers FUNCTIONAL BLOCK DIAGRAM ENBL VPSD COMD LE CLK DATA SDO COM VPS OPP1 OPM1 COM GAIN VOCM COM OPM2 OPP2 INP1 INM1 VPS ADRF6510 COM GNSW OFS1 VPS COM INP2 INM2 VPS COM OFDS OFS2 VPS 09002-001 SPI Figure 1. GENERAL DESCRIPTION The ADRF6510 is a matched pair of fully differential low noise and low distortion programmable filters and variable gain ampli- fiers (VGAs). Each channel is capable of rejecting large out-of- band interferers while reliably boosting the wanted signal, thus reducing the bandwidth and resolution requirements on the analog-to-digital converters (ADCs). The excellent matching between channels and their high spurious-free dynamic range over all gain and bandwidth settings makes the ADRF6510 ideal for quadrature-based (IQ) communication systems with dense constellations, multiple carriers, and nearby interferers. The filters provide a six-pole Butterworth response with 0.5 dB corner frequencies programmable through the SPI port from 1 MHz to 30 MHz in 1 MHz steps. The preamplifier that precedes the filters offers a pin-programmable option of either 6 dB or 12 dB of gain. The preamplifier sets a differential input imped- ance of 400 Ω and has a common-mode voltage that defaults to 2.1 V but can be driven from 1.5 V to 2.5 V. The variable gain amplifiers that follow the filters provide 50 dB of continuous gain control with a slope of 30 mV/dB. The output buffers provide a differential output impedance of 20 Ω that is capable of driving 1.5 V p-p into 1 kΩ loads. The output common- mode voltage defaults to VPS/2, but it can be programmed via the VOCM pin. The built-in dc offset correction loop can be disabled if dc-coupled operation is desired. The high-pass corner frequency is defined by external capacitors on the OFS1 and OFS2 pins. The ADRF6510 operates from a 4.75 V to 5.25 V supply and consumes a maximum supply current of 258 mA when pro- grammed to the highest bandwidth setting. When disabled, it consumes 2 mA. The ADRF6510 is fabricated in an advanced silicon-germanium BiCMOS process and is available in a 32-lead, exposed paddle LFCSP. Performance is specified over the −40°C to +85°C temperature range.

Transcript of ADRF6510 (Rev. B) - Analog Devices

30 MHz Dual Programmable Filters and Variable Gain Amplifiers

Data Sheet ADRF6510

Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 ©2010-2017 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com

FEATURES Matched pair of programmable filters and VGAs Continuous gain control range: −5 dB to +45 dB 6-pole filter

1 MHz to 30 MHz in 1 MHz steps, 0.5 dB corner frequency SPI programmable

6 dB front-end gain step IMD3: >55 dBc for 1.5 V p-p composite output HD2, HD3: >60 dBc for 1.5 V p-p output Differential input and output Adjustable output common-mode voltage Optional dc output offset correction Power-down feature Single 5 V supply operation

APPLICATIONS Baseband I/Q receivers Diversity receivers ADC drivers

FUNCTIONAL BLOCK DIAGRAM ENBL

VPSD

COMD

LE

CLK

DATA

SDO

COM

VPS

OPP1

OPM1

COM

GAIN

VOCM

COM

OPM2

OPP2

INP1 INM1 VPS

ADRF6510

COM GNSW OFS1 VPS

COM INP2 INM2 VPS COM OFDS OFS2 VPS 09002-001

SPI

Figure 1.

GENERAL DESCRIPTION The ADRF6510 is a matched pair of fully differential low noise and low distortion programmable filters and variable gain ampli-fiers (VGAs). Each channel is capable of rejecting large out-of-band interferers while reliably boosting the wanted signal, thus reducing the bandwidth and resolution requirements on the analog-to-digital converters (ADCs). The excellent matching between channels and their high spurious-free dynamic range over all gain and bandwidth settings makes the ADRF6510 ideal for quadrature-based (IQ) communication systems with dense constellations, multiple carriers, and nearby interferers.

The filters provide a six-pole Butterworth response with 0.5 dB corner frequencies programmable through the SPI port from 1 MHz to 30 MHz in 1 MHz steps. The preamplifier that precedes the filters offers a pin-programmable option of either 6 dB or 12 dB of gain. The preamplifier sets a differential input imped-ance of 400 Ω and has a common-mode voltage that defaults to 2.1 V but can be driven from 1.5 V to 2.5 V.

The variable gain amplifiers that follow the filters provide 50 dB of continuous gain control with a slope of 30 mV/dB. The output buffers provide a differential output impedance of 20 Ω that is capable of driving 1.5 V p-p into 1 kΩ loads. The output common-mode voltage defaults to VPS/2, but it can be programmed via the VOCM pin. The built-in dc offset correction loop can be disabled if dc-coupled operation is desired. The high-pass corner frequency is defined by external capacitors on the OFS1 and OFS2 pins.

The ADRF6510 operates from a 4.75 V to 5.25 V supply and consumes a maximum supply current of 258 mA when pro-grammed to the highest bandwidth setting. When disabled, it consumes 2 mA. The ADRF6510 is fabricated in an advanced silicon-germanium BiCMOS process and is available in a 32-lead, exposed paddle LFCSP. Performance is specified over the −40°C to +85°C temperature range.

ADRF6510 Data Sheet

Rev. B | Page 2 of 32

TABLE OF CONTENTS Features .............................................................................................. 1 Applications ....................................................................................... 1 Functional Block Diagram .............................................................. 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications ..................................................................................... 3

Timing Diagrams .......................................................................... 5 Absolute Maximum Ratings ............................................................ 6

ESD Caution .................................................................................. 6 Pin Configuration and Function Descriptions ............................. 7 Typical Performance Characteristics ............................................. 8 Theory of Operation ...................................................................... 15

Input Buffers ............................................................................... 15 Programmable Filters ................................................................. 15 Variable Gain Amplifiers (VGAs) ............................................ 16 Output Buffers/ADC Drivers ................................................... 16 DC Offset Compensation Loop ................................................ 16 Programming the Filters ............................................................ 17 Noise Characteristics ................................................................. 17

Distortion Characteristics ......................................................... 18 Maximizing the Dynamic Range ............................................. 18 Key Parameters for Quadrature-Based Receivers .................. 19

Applications Information .............................................................. 20 Basic Connections ...................................................................... 20 Error Vector Magnitude (EVM) Performance ........................... 20 EVM ............................................................................................. 21 Effect of Filter Bandwidth on EVM ......................................... 21 Effect of Output Voltage Levels on EVM ................................ 21 Effect of COFS on EVM ............................................................... 22 Anti-Aliasing Filter .................................................................... 22

Evaluation Board ............................................................................ 24 Evaluation Board Control Software ......................................... 24 Schematics and Artwork ........................................................... 24 Evaluation Board Configuration Options ............................... 27

Outline Dimensions ....................................................................... 29 Ordering Guide .......................................................................... 29

REVISION HISTORY 9/2017—Rev. A to Rev. B Changed CP-32-2 to CP-32-7 ...................................... Throughout Updated Outline Dimensions ....................................................... 29 Changes to Ordering Guide .......................................................... 29

10/2011—Rev. 0 to Rev. A Changes to Figure 2 and Figure 3 ................................................... 5 Changes to Table 3 ............................................................................ 7 Changes to Figure 48, Changes to Error Vector Magnitude (EVM) Performance Section ......................................................... 20 Deleted Low IF Image Rejection Section, and Example Baseband Interface Section, Figure 50, and Figure 51; Renumbered Subsequent Figures ................................................. 20 Changes to Figure 49 ...................................................................... 21

Added EVM Section, Effect of Filter Bandwidth on EVM Section, Effect of Output Voltage Levels on EVM Section, and Effect of COFS on EVM Section...................................................... 21 Added Anti-Aliasing Filter Section .............................................. 22 Changes to Figure 54 ...................................................................... 22 Changes to Figure 58 ...................................................................... 24 Changes to Figure 61 ...................................................................... 25 Changes to Figure 62 and Figure 63 ............................................ 26 Changes to Table 5 .......................................................................... 27

4/2010—Revision 0: Initial Version

Data Sheet ADRF6510

Rev. B | Page 3 of 32

SPECIFICATIONS VPS = 5 V, TA = 25°C, ZSOURCE = 400 Ω, ZLOAD = 1 kΩ, VOUT = 1.5 V p-p, bandwidth setting = 30 MHz, GNSW = 0 V, unless otherwise noted.

Table 1. Parameter Test Conditions/Comments Min Typ Max Unit FREQUENCY RESPONSE

Low-Pass Corner Frequency, fC Six-pole Butterworth filter, 0.5 dB bandwidth 1 30 MHz Step Size 1 MHz Corner Frequency Absolute

Accuracy Over operating temperature range ±15 % fC

Corner Frequency Matching Channel A and Channel B at same gain and bandwidth settings

±0.5 % fC

Pass-Band Ripple 0.5 dB p-p Gain Matching Channel A and Channel B at same gain and

bandwidth settings ±0.1 dB

Group Delay Variation From midband to peak Corner Frequency = 1 MHz 135 ns Corner Frequency = 30 MHz 11 ns

Group Delay Matching Channel A and Channel B at same gain Corner Frequency = 1 MHz 5 ns Corner Frequency = 30 MHz 0.2 ns

Stop-Band Rejection Relative to Pass Band 2 × fC 30 dB 5 × fC 75 dB

INPUT STAGE INP1, INM1, INP2, INM2 Maximum Input Swing At minimum gain, VGAIN = 0 V 1 V p-p Differential Input Impedance 400 Ω Input Common-Mode Range 1 V p-p input voltage 1.5 VPS/2 V

Input pins left floating VPS/2 V GAIN CONTROL GAIN, GNSW

Voltage Gain Range GNSW = 0 V, VGAIN from 0 V to 2 V −5 +45 dB GNSW = 5 V 1 51 dB Gain Slope 30 mV/dB Gain Error VGAIN from 500 mV to 1.7 V 0.2 dB Gain Step GNSW = 0 V to 5 V 6 dB

OUTPUT STAGE OPP1, OPM1, OPP2, OPM2, VOCM Maximum Output Swing At maximum gain, RLOAD = 1 kΩ 2 V p-p HD2 > 60 dBc, HD3 > 60 dBc 1.5 V p-p Differential Output Impedance 20 Ω Output DC Offset Inputs shorted, offset loop disabled 35 mV Output Common-Mode Range 1.5 V p-p output voltage 1.5 3.0 V

VOCM left floating VPS/2 V NOISE/DISTORTION

1 MHz Corner Frequency Output Noise Density Gain = 0 dB at fC/2 −129 dBV/√Hz Gain = 20 dB at fC/2 −127 dBV/√Hz Gain = 40 dB at fC/2 −111 dBV/√Hz Second Harmonic, HD2 250 kHz fundamental, 1.5 V p-p output voltage Gain = 0 dB 46.2 dBc Gain = 40 dB 43.2 dBc Third Harmonic, HD3 250 kHz fundamental, 1.5 V p-p output voltage Gain = 0 dB 52.2 dBc Gain = 40 dB 51.2 dBc

ADRF6510 Data Sheet

Rev. B | Page 4 of 32

Parameter Test Conditions/Comments Min Typ Max Unit IMD3 f1 = 500 kHz, f2 = 550 kHz, 1.5 V p-p composite

output voltage

Gain = 5 dB 61 dBc Gain = 35 dB 57 dBc IMD3 with Input CW Blocker f1 = 500 kHz, f2 = 550 kHz, 1.5 V p-p composite

output, gain = 5 dB; blocker at 5 MHz, 10 dBc relative to two-tone composite output voltage

40 dBc

30 MHz Corner Frequency Output Noise Density Midband, gain = 0 dB −130 dBV/√Hz Midband, gain = 20 dB −130 dBV/√Hz Midband, gain = 40 dB −123 dBV/√Hz Second Harmonic, HD2 8 MHz fundamental, 1.5 V p-p output voltage Gain = 0 dB 63 dBc Gain = 40 dB 84 dBc Third Harmonic, HD3 8 MHz fundamental, 1.5 V p-p output voltage Gain = 0 dB 54 dBc Gain = 40 dB 87 dBc IMD3 f1 = 15 MHz, f2 = 16 MHz, 1.5 V p-p composite

output voltage

Gain = 5 dB 59 dBc Gain = 35 dB 77.5 dBc IMD3 with Input CW Blocker f1 = 15 MHz, f2 = 16 MHz, 1.5 V p-p composite

output, gain = 5 dB; blocker at 150 MHz, 10 dBc relative to two-tone composite output voltage

55 dBc

DIGITAL LOGIC LE, CLK, DATA, SDO, OFDS, GNSW Input High Voltage, VINH >2 V Input Low Voltage, VINL <0.8 V Input Current, IINH/IINL <1 µA Input Capacitance, CIN 2 pF

SPI TIMING LE, CLK, DATA, SDO fCLK 1/tCLK 20 MHz tDH DATA hold time 5 ns tDS DATA setup time 5 ns tLH LE hold time 5 ns tLS LE setup time 5 ns tPW CLK high pulse width 5 ns tD CLK to SDO delay 5 ns

POWER AND ENABLE VPS, VPSD, COM, COMD, ENBL Supply Voltage Range 4.75 5.0 5.25 V Total Supply Current ENBL = 5 V Maximum bandwidth setting 258 mA Minimum bandwidth setting 131 mA Disable Current ENBL = 0 V 2 mA Disable Threshold 2.5 V Enable Response Time Delay following ENBL low-to-high transition 20 µs Disable Response Time Delay following ENBL high-to-low transition 300 ns

Data Sheet ADRF6510

Rev. B | Page 5 of 32

TIMING DIAGRAMS

WRITE BIT MSB - 2LSB + 1LSB

NOTES1. THE FIRST DATA BIT DETERMINES WHETHER THE PART IS WRITING TO OR READING FROM THE INTERNAL CORNER FREQUENCY

WORD REGISTER. FOR A WRITE OPERATION, THE FIRST BIT SHOULD BE A LOGIC 1. THE CORNER FREQUENCY WORD BIT IS THENREGISTERED INTO THE DATA PIN ON CONSECUTIVE RISING EDGES OF THE CLOCK.

CLK

LE

DATA MSB – 2 MSB – 1 MSB

09002-003

tPW

tLH

tCLK

tLS

tDS tDH

Figure 2. Write Mode Timing Diagram

DCDCREAD BIT DC DC DC

LSB + 1LSB

DATA

SDO

NOTES1. THE FIRST DATA BIT DETERMINES WHETHER THE PART IS WRITING TO OR READING FROM THE INTERNAL CORNER FREQUENCY WORD

REGISTER. FOR A READ OPERATION, THE FIRST BIT SHOULD BE A LOGIC 0. THE CORNER FREQUENCY WORD BIT IS THEN UPDATED ATTHE SDO PIN ON CONSECUTIVE FALLING EDGES OF THE CLOCK.

MSB – 2 MSB – 1 MSB

09002-004

tDS tDH

CLK

LE

tPWtCLKtD

tLS

Figure 3. Read Mode Timing Diagram

ADRF6510 Data Sheet

Rev. B | Page 6 of 32

ABSOLUTE MAXIMUM RATINGS Table 2. Parameter Rating Supply Voltages, VPS, VPSD 5.25 V ENBL, GNSW, OFDS, LE, CLK, DATA, SDO VPS + 0.6 V INP1, INM1, INP2, INM2 VPS + 0.6 V,

GND − 0.6 V OPP1, OPM1, OPP2, OPM2 VPS + 0.6 V OFS1, OFS2 VPS + 0.6 V GAIN VPS + 0.6 V Internal Power Dissipation 1.4 W θJA (Exposed Pad Soldered to Board) 37.4°C/W Maximum Junction Temperature 150°C Operating Temperature Range −40°C to +85°C Storage Temperature Range −65°C to +150°C Lead Temperature (Soldering 60 sec) 300°C

Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability.

ESD CAUTION

Data Sheet ADRF6510

Rev. B | Page 7 of 32

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

VPSDCOMD

LECLK

DATASDOCOMVPS

OPP1OPM1COMGAINVOCMCOMOPM2OPP2

CO

MIN

P2

INM

2V

PS

CO

MO

FD

SO

FS

2V

PS

EN

BL

INP

1IN

M1

VP

SC

OM

GN

SW

OF

S1

VP

S

090

02

-00

2

NOTES1. CONNECT THE EXPOSED PADDLE TO

A LOW IMPEDANCE GROUND PAD.

2423222120191817

12345678

9 10 11 12 13 14 15 16

32 31 30 29 28 27 26 25

ADRF6510TOP VIEW

(Not to Scale)

Figure 4. Pin Configuration

Table 3. Pin Function Descriptions Pin No. Mnemonic Description 1 VPSD Digital Positive Supply Voltage: 4.75 V to 5.25 V. 2 COMD Digital Common. Connect to external circuit common using the lowest possible impedance. 3 LE Latch Enable. SPI programming pin. CMOS levels: VLOW < 0.8 V, VHIGH > 2 V. 4 CLK SPI Port Clock. CMOS levels: VLOW < 0.8 V, VHIGH > 2 V. 5 DATA SPI Data Input. CMOS levels: VLOW < 0.8 V, VHIGH > 2 V. 6 SDO SPI Data Output. CMOS levels: VLOW < 0.8 V, VHIGH > 2 V. 7, 9, 13, 19, 22, 28 COM Analog Common. Connect to external circuit common. 8, 12, 16, 25, 29 VPS Analog Positive Supply Voltage: 4.75 V to 5.25 V. 10, 11, 30, 31 INP2, INM2,

INM1, INP1 Differential Inputs. 400 Ω input impedance. Common-mode range is 1.5 V to 2.5 V; default is 2.1 V.

14 OFDS Offset Correction Loop Disable. Pull high to disable the offset correction loop. 15, 26 OFS2, OFS1 Offset Correction Loop Compensation Capacitors. Connect capacitors to circuit common. 17, 18, 23, 24 OPP2, OPM2,

OPM1, OPP1 Differential Outputs. 20 Ω output impedance. Common-mode range is 1.5 V to 3 V; default is VPS/2.

20 VOCM Output Common-Mode Setpoint. Defaults to VPS/2 if left open. 21 GAIN Analog Gain Control. 0 V to 2 V, 30 mV/dB gain scaling. 27 GNSW Front-End Gain Switch, 6 dB or 12 dB. Pull low for 6 dB; pull high for 12 dB. 32 ENBL Chip Enable. Pull high to enable. EP Exposed Paddle. Connect the exposed paddle to a low impedance ground pad.

ADRF6510 Data Sheet

Rev. B | Page 8 of 32

TYPICAL PERFORMANCE CHARACTERISTICS VPS = 5 V, TA = 25°C, ZSOURCE = 400 Ω, ZLOAD = 1 kΩ, VOUT = 1.5 V p-p, GNSW = 0 V, unless otherwise noted.

50

45

40

35

30

25

20

15

10

5

0

–5

–100 200 400 600 800 1000 1200 1400 1600 1800 22002000

GA

IN (d

B)

VGAIN (mV) 09002-005

BANDWIDTH = 30MHz

+25°CVPS = 4.75V, 5V, 5.25V

+85°CVPS = 4.75V, 5V, 5.25V

–40°CVPS = 4.75V, 5V, 5.25V

Figure 5. In-Band Gain vs. VGAIN over Supply and Temperature

(Bandwidth Setting = 30 MHz)

50

–501 10 100

GA

IN (d

B)

FREQUENCY (MHz) 09002-006

–45–40–35–30–25–20–15–10–5

05

1015202530354045 BANDWIDTH = 30MHz

Figure 6. Gain vs. Frequency by VGAIN (Bandwidth Setting = 30 MHz)

0.25

0.20

0.15

0.10

0.05

0

–0.050 2.2

GA

IN M

ISM

ATC

H (d

B)

VGAIN (V) 09002-007

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

BANDWIDTH = 30MHz

Figure 7. Gain Matching vs. VGAIN (Bandwidth Setting = 30 MHz)

3.0

2.5

2.0

1.5

1.0

0.5

0

–0.5

–1.0

–1.5

–2.0

–3.0

–2.5

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

GA

IN E

RR

OR

(dB

)

VGAIN (mV) 09002-008

+85°CVPS = 4.25V, 5V, 5.25V

BANDWIDTH = 30MHz

+25°CVPS = 4.25V, 5V, 5.25V

–40°CVPS = 4.25V, 5V, 5.25V

Figure 8. Gain Conformance vs. VGAIN over Supply and Temperature

(Bandwidth Setting = 30 MHz)

5

3

1

–1

–3

–5

–7

–9

9

8

7

6

5

4

3

20 5 10 15 4035302520

GA

IN E

RR

OR

(dB

)

GA

IN S

TEP

(dB

)

FREQUENCY (MHz) 09002-009

BANDWIDTH = 30MHz

PREAMP GAIN = 12dB

PREAMP GAIN = 6dB

Figure 9. 6 dB Gain Step and Gain Error vs. Frequency

(Bandwidth Setting = 30 MHz, VGAIN = 0 V)

15

10

5

0

–5

–10

–150 5 10 15 20 25 30 35 40

OP1

dB (d

BV

rms)

GAIN (dB) 09002-010

PREAMP GAIN = 6dBPREAMP GAIN = 12dB

Figure 10. Output P1dB vs. GAIN at 15 MHz (Bandwidth Setting = 30 MHz)

Data Sheet ADRF6510

Rev. B | Page 9 of 32

40

35

30

25

20

15

10

–10

–5

0

5

1M 100M10M

GA

IN (d

B)

FREQUENCY (Hz) 09002-011

Figure 11. Frequency Response vs. Bandwidth Setting (Gain = 30 dB),

Log Scale

32

31

28

29

30

271 40

GA

IN (d

B)

FREQUENCY (MHz) 09002-012

6 11 16 21 26 31 36

Figure 12. Frequency Response vs. Bandwidth Setting (Gain = 30 dB),

Linear Scale

30

152 40

GA

IN (d

B)

FREQUENCY (MHz) 09002-013

1617181920212223242526272829

4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38

–40°C

+25°C

+85°C

Figure 13. Frequency Response over Temperature

(Gain = 26 dB, Bandwidth Setting = 30 MHz)

1000

00.5 5 50

GR

OU

P D

ELA

Y (n

s)

FREQUENCY (MHz) 09002-014

100

200

300

400

500

600

700

800

900GAIN = 20dB

BW = 1MHz

BW = 5MHz

BW = 10MHzBW = 20MHz

BW = 30MHz

Figure 14. Group Delay vs. Frequency (Gain = 20 dB)

1.0

0.5

0

–0.5

–1.00.5 5 30

GR

OU

P D

ELA

Y M

ATC

HIN

G (n

s)

FREQUENCY (MHz) 09002-015

GAIN = 20dB

GAIN = 40dB

BANDWIDTH = 30MHz

Figure 15. Group Delay Mismatch vs. Frequency

(Bandwidth Setting = 30 MHz)

5

4

3

2

1

0

–1

–2

–3

–4

–50.2 0.4 0.6 0.8 1.0 1.2 1.4

IQ G

RO

UP

DEL

AY

MA

TCH

ING

(ns)

FREQUENCY (MHz) 09002-016

GAIN = 20dB

GAIN = 0dB

BANDWIDTH = 1MHz

Figure 16. IQ Group Delay Mismatch vs. Frequency

(Bandwidth Setting = 1 MHz)

ADRF6510 Data Sheet

Rev. B | Page 10 of 32

0.75

–0.750 30

IQ A

MP

LIT

UD

E M

ISM

AT

CH

(d

B)

FREQUENCY (MHz)

FREQUENCY (MHz)

090

02-0

17

0 0.5 1.0 1.5 2.0 2.5 3.0

–0.50

–0.25

0

0.25

0.50

5 10 15 20 25

BANDWIDTH = 30MHz

BANDWIDTH = 1MHz

Figure 17. IQ Amplitude Mismatch vs. Frequency

90

400 40

HD

2 @

16M

Hz

(dB

c)

GAIN (dB) 0900

2-01

8

5 10 15 20 25 30 35

45

50

55

60

65

70

75

80

85

+25°C, VPS = 4.75V+25°C, VPS = 5V+25°C, VPS = 5.25V+85°C, VPS = 4.75V+85°C, VPS = 5V+85°C, VPS = 5.25V–40°C, VPS = 4.75V–40°C, VPS = 5V–40°C, VPS = 5.25V

Figure 18. HD2 vs. Gain over Supply and Temperature (Bandwidth Setting = 30 MHz)

100

90

30

40

50

60

70

80

0 5 10 15 20 25 30 35 40

HD

2 @

16M

Hz

(dB

c)

GAIN (dB) 0900

2-01

9

1.5V p-p OUTPUT @ 8MHzBANDWIDTH = 30MHz

VOCM = 1.5VVOCM = 1.75VVOCM = 2VVOCM = 2.5V

Figure 19. HD2 vs. Gain over Output Common-Mode Voltage (Bandwidth Setting = 30 MHz)

100

400 40

HD

3 @

24M

Hz

(dB

c)

GAIN (dB) 0900

2-02

0

5 10 15 20 25 30 35

+25°C, VPS = 4.75V+25°C, VPS = 5V+25°C, VPS = 5.25V+85°C, VPS = 4.75V+85°C, VPS = 5V+85°C, VPS = 5.25V–40°C, VPS = 4.75V–40°C, VPS = 5V–40°C, VPS = 5.25V

50

60

70

80

90

Figure 20. HD3 vs. Gain over Supply and Temperature (Bandwidth Setting = 30 MHz)

100

90

80

70

60

50

400 40

HD

3 @

24M

Hz

(dB

c)

GAIN (dB) 0900

2-0

21

1.5V p-p OUTPUT @ 8MHzBANDWIDTH = 30MHz

VOCM = 1.5VVOCM = 1.75VVOCM = 2VVOCM = 2.5V

5 10 15 20 25 30 35

Figure 21. HD3 vs. Gain over Output Common-Mode Voltage (Bandwidth Setting = 30 MHz)

30

25

20

15

10

5

00 5 504540353025201510

OIP

3 (d

BV

)

GAIN (dB) 0900

2-0

22

BANDWIDTH = 30MHzf1 = 14MHz, f2 = 15MHz

PREAMPGAIN = 6dB

PREAMPGAIN = 12dB

Figure 22. In-Band OIP3 vs. Gain (Bandwidth Setting = 30 MHz)

Data Sheet ADRF6510

Rev. B | Page 11 of 32

30

25

20

15

10

5

00 403530252015105

OIP

3 (d

BV

)

GAIN (dB) 0900

2-02

3

BANDWIDTH = 30MHzf1 = 14MHz, f2 = 15MHz

+25°C

+85°C

–40°C

Figure 23. In-Band OIP3 vs. Gain over Temperature (Preamp Gain = 6 dB, Bandwidth Setting = 30 MHz)

120

00 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

IMD

3 (d

Bc)

COMPOSITE OUTPUT VOLTAGE (V p-p)

090

02-0

24

GAIN = 0dBGAIN = 10dBGAIN = 20dBGAIN = 30dBGAIN = 40dB

20

40

60

80

100

Figure 24. In-Band Third-Order Intermodulation Distortion (Preamp Gain = 6 dB, Bandwidth Setting = 30 MHz)

120

00 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

IMD

3 (d

Bc)

COMPOSITE OUTPUT VOLTAGE (V p-p)

090

02-0

25

GAIN = 6dBGAIN = 16dBGAIN = 26dBGAIN = 36dBGAIN = 46dB

20

40

60

80

100

Figure 25. In-Band Third-Order Intermodulation Distortion (Preamp Gain = 12 dB, Bandwidth Setting = 30 MHz)

65

–145–45 65

IMD

2 @

15M

Hz

(dB

V)

INPUT LEVEL @ 115MHz AND 130MHz (dBV/Tone) 090

02-0

60

–135–125–115–105–95–85–75–65–55–45–35–25–15–55

1525354555

–35 –25 –15 –5 5 15 25 35 45 55

BANDWIDTH = 30MHz

PREAMPGAIN = 12dB

OUT-OF-BAND IIP2

2:1 SLOPE

PREAMPGAIN = 6dB

Figure 26. Out-of-Band IIP2: IMD2 Tone at Midband (Bandwidth Setting = 30 MHz)

10

0

–130–45 5

IMD

3 @

15M

Hz

(dB

V)

INPUT LEVEL @ 115MHz AND 215MHz (dBV/Tone) 0900

2-0

27

–120

–110

–100

–90

–80

–70

–60

–50

–40

–30

–20

–10

–40 –35 –30 –25 –20 –15 –10 –5 0

BANDWIDTH = 30MHz

PREAMPGAIN = 12dB

OUT-OF-BAND IIP3

3:1 SLOPE

PREAMPGAIN = 6dB

Figure 27. Out-of-Band IIP3: IMD3 Tone at Midband (Bandwidth Setting = 30 MHz)

70

65

60

55

50

45

40

35

30

25

20–5 0 5 10 15 20 25 30 35 40 45

NO

ISE

FIG

UR

E (

dB

re

50Ω

)

GAIN (dB) 090

02-0

28

1MHz BW2MHz BW4MHz BW6MHz BW8MHz BW30MHz BW

Figure 28. Noise Figure vs. Gain over Bandwidth Setting, Preamp Gain = 6 dB (Noise Figure at 1/2 Bandwidth)

ADRF6510 Data Sheet

Rev. B | Page 12 of 32

60

55

50

45

40

35

30

25

20

15

100 5 10 15 20 25 30 35 40 45 50

NO

ISE

FIG

UR

E (d

B re

50Ω

)

GAIN (dB) 09002-029

1MHz BW2MHz BW4MHz BW6MHz BW8MHz BW30MHz BW

Figure 29. Noise Figure vs. Gain over Bandwidth Setting,

Preamp Gain = 12 dB (Noise Figure at 1/2 Bandwidth)

–100

–105

–110

–115

–120

–125

–130

–135–5 0 5 10 15 20 25 30 35 40 45

OU

TPU

T N

OIS

E (d

BV

rms/

√Hz)

GAIN (dB) 09002-030

1MHz BW2MHz BW4MHz BW6MHz BW8MHz BW30MHz BW

Figure 30. Output Noise Density vs. Gain by Bandwidth Setting,

Preamp Gain = 6 dB (Noise at 1/2 Bandwidth)

–100

–105

–110

–115

–120

–125

–130

–1350 5 10 15 20 25 30 35 40 45 50

OU

TPU

T N

OIS

E (d

BV

rms/

√Hz)

GAIN (dB) 09002-031

1MHz BW2MHz BW4MHz BW6MHz BW8MHz BW30MHz BW

Figure 31. Output Noise Density vs. Gain by Bandwidth Setting,

Preamp Gain = 12 dB (Noise at 1/2 Bandwidth)

–90

–95

–100

–105

–110

–115

–120

–125

–130

–135

–1400.5 3.02.52.01.51.0

OU

TPU

T N

OIS

E (d

BV

rms/

√Hz)

FREQUENCY (MHz) 09002-032

GAIN = 0dBGAIN = 20dBGAIN = 40dB

Figure 32. Output Noise Density vs. Frequency (Bandwidth Setting = 1 MHz)

–110

–115

–120

–125

–130

–135

–14010 3018 20 22 24 26 28161412

OU

TPU

T N

OIS

E (d

BV

rms/

√Hz)

FREQUENCY (MHz) 09002-033

GAIN = 0dBGAIN = 20dBGAIN = 40dB

Figure 33. Output Noise Density vs. Frequency (Bandwidth Setting = 20 MHz)

–90

–140–35 –30 –25 –20 –15 –10

OU

TPU

T N

OIS

E @

15M

Hz

(dB

V/√H

z)

BLOCKER LEVEL @ 150MHz (dBV rms) 09002-034

GAIN = 40dB

GAIN = 20dB

GAIN = 0dB

–135

–130

–125

–120

–115

–110

–105

–100

–95

Figure 34. Output Noise Density vs. Blocker Level

(Bandwidth Setting = 30 MHz, Blocker at 150 MHz)

Data Sheet ADRF6510

Rev. B | Page 13 of 32

450

3500 5 10 15 20 25 30

RIN

(Ω)

CIN

(pF)

FREQUENCY (MHz) 09002-035

360

370

380

390

400

410

420

430

440

10

–40

–35

–30

–25

–20

–15

–10

–5

0

5

Figure 35. Input Impedance vs. Frequency (Bandwidth Setting = 30 MHz)

28

27

26

25

24

23

22

21

20

200

100

0

–100

–200

–300

–400

–500

–6000 30

RSE

RIE

S_O

UT

(Ω)

L SER

IES_

OU

T (n

H)

FREQUENCY (MHz) 09002-036

5 10 15 20 25

Figure 36. Output Impedance vs. Frequency (Bandwidth Setting = 30 MHz)

90

00.1 1 10 100

ISO

LATI

ON

(dB

)

FREQUENCY (MHz) 09002-037

10

20

30

40

50

60

70

80BANDWIDTH = 30MHz

GAIN = 40dB

GAIN = 20dB

GAIN = 0dB

Figure 37. Channel Isolation, Output to Output, vs. Frequency

(Bandwidth Setting = 30 MHz)

280

260

240

220

200

180

160

100

120

140

0 5 10 15 20 25 30

I SU

PPLY

(mA

)

BANDWIDTH SETTING (MHz) 09002-038

Figure 38. Current Consumption vs. Bandwidth Setting (Gain = 20 dB)

266

264

248

250

252

254

256

258

260

262

–50 –30 –10 10 30 50 70 90

I SU

PPLY

(mA

)

TEMPERATURE (°C) 09002-039

VPS = 4.75VVPS = 5VVPS = 5.25V

Figure 39. Current Consumption vs. Temperature over Supply

(Bandwidth Setting = 30 MHz)

70

00 30

CM

RR

(dB

)

FREQUENCY (MHz) 09002-040

10

20

30

40

50

60

5 10 15 20 25

BANDWIDTH = 30MHz

GAIN = 40dB

GAIN = 20dB

Figure 40. Common-Mode Rejection Ratio vs. Frequency

(Bandwidth Setting = 30 MHz)

ADRF6510 Data Sheet

Rev. B | Page 14 of 32

0900

2-06

7

INPUT SIGNAL = 45mV p-pOUTPUT SIGNAL = 450mV p-p20dB OF GAINVGAIN = 800mV TO 1.40V

400ns/DIV

30MHz BANDWIDTH,28MHz MAINTONE

VGAIN = 1400mVTO 800mV

28MHz SIGNAL = 45mV p-pTO 450mV p-p

Figure 41. Gain Step Response

Data Sheet ADRF6510

Rev. B | Page 15 of 32

THEORY OF OPERATION The ADRF6510 consists of a matched pair of buffered, program-mable filters followed by variable gain amplifiers and output ADC drivers. The block diagram of a single channel is shown in Figure 42. The programmability of the bandwidth and of the pre- and post-filtering gain offers great flexibility when coping with signals of varying levels in the presence of noise and large, undesired signals nearby. The entire differential signal chain is dc-coupled with flexible interfaces at the input and output. The bandwidth and gain setting controls for the two channels are shared, ensuring close matching of their magnitude and phase responses. The ADRF6510 can be fully disabled through the ENBL pin.

SPIINTERFACE

6dB/12dBPREAMP

PREAMPGAIN SWITCH

1MHz TO 30MHzPROG. FILTERS

50dBVGA

OUTPUT ADCDRIVER

BASEBANDINPUTS

BASEBANDOUTPUTS

FILTERPROGRAMMING

SPI BUS

ANALOGGAIN CONTROL

30mV/dBOUTPUT

COMMON-MODECONTROL

09

00

2-0

42

Figure 42. Signal Path Block Diagram for a Single Channel of the ADRF6510

Filtering and amplification are fundamental operations in any signal processing system. Filtering is necessary to select the intended signal while rejecting out-of-band noise and interferers. Amplification increases the level of the desired signal to overcome noise added by the system. When used together, filtering and amplification can extract a low level signal of interest in the presence of noise and out-of-band interferers. Such analog signal processing alleviates the requirements on the analog, mixed signal, and digital components that follow.

INPUT BUFFERS The input buffers provide a convenient interface to the sensitive filter sections that follow. They set a differential input impedance of 400 Ω and sit at a nominal common-mode voltage of VPS/2. The inputs can be dc-coupled or ac-coupled. If using direct dc-coupling, the common-mode voltage, VCM, can range from 1.5 V to 3 V. A current flows into or out of the input pins to accommodate the difference in common-mode voltages. The current into each pin is given by

(VCM – (VPS/2))/200 Ω

The input buffers in both channels can be configured simulta-neously to a gain of 6 dB or 12 dB through the GNSW pin. When configured for a 6 dB gain, the buffers support up to a 1 V p-p differential input level with >50 dBc harmonic distortion. For a 12 dB gain setting, the buffers support 0.5 V p-p inputs.

PROGRAMMABLE FILTERS The integrated programmable filter is the key signal processing function in the ADRF6510. The filters follow a six-pole Butter-worth prototype response that provides a compromise between

band rejection, ripple, and group delay. The 0.5 dB bandwidth is programmed from 1 MHz to 30 MHz in 1 MHz steps via the serial programming interface (SPI) as described in the Programming the Filters section.

The filters are designed so that the Butterworth prototype filter shape and group delay responses vs. frequency are retained for any bandwidth setting. Figure 43 and Figure 44 illustrate the ideal six-pole Butterworth gain and group delay responses, respectively. The group delay, τg, is defined as

τg = −∂φ/∂ω

where: φ is the phase in radians. ω = 2πf is the frequency in radians/second.

Note that for a frequency scaled filter prototype, the absolute magnitude of the group delay scales inversely with the band-width; however, the shape is retained. For example, the peak group delay for a 28 MHz bandwidth setting is 14× less than for a 2 MHz setting.

0

–20

–40

–60

–80

–100

–120

–140

–160

–1801M 10M 100M 1G

RE

LA

TIV

E M

AG

NIT

UD

E (

Hz)

FREQUENCY (Hz) 0900

2-0

43

Figure 43. Sixth-Order Butterworth Magnitude Response for 0.5 dB Bandwidths; Programmed from 2 MHz to 29 MHz in 1 MHz Steps

500

400

300

200

100

0

–100100k 1M 10M 100M

GR

OU

P D

EL

AY

(n

s)

FREQUENCY (Hz) 0900

2-0

442MHz 28MHz

14x

Figure 44. Sixth-Order Butterworth Group Delay Response for

0.5 dB Bandwidths; Programmed to 2 MHz and 28 MHz

ADRF6510 Data Sheet

Rev. B | Page 16 of 32

The corner frequency of the filters is defined by RC products, which can vary by ±30% in a typical process. Therefore, all the parts are factory calibrated for corner frequency, resulting in a residual ±10% corner frequency variation over the −40°C to +85°C temperature range. Although absolute accuracy requires calibration, the matching of RC products between the pair of channels is better than 1% by observing careful design and layout practices. Calibration and excellent matching ensure that the magnitude and group delay responses of both channels track together, a critical requirement for digital IQ-based communication systems.

VARIABLE GAIN AMPLIFIERS (VGAs) The VGAs are implemented using the Analog Devices, Inc., patented X-AMP® architecture, consisting of a tapped 50 dB attenuator followed by a fixed-gain amplifier. The X-AMP archi-tecture generates a linear-in-dB monotonic gain response with low ripple. The gain is controlled through the high impedance GAIN pin with an accurate slope of 30 mV/dB. The gain response shown in Figure 45 shows the GAIN pin voltage range and the absence of gain foldback at high VGAIN.

50

–10

0.3

–0.30 4.0

GA

IN (d

B)

GA

IN E

RR

OR

(dB

)

VGAIN (V) 09002-045

0

10

20

30

40

0.5 1.0 1.5 2.0 2.5 3.0 3.5

–0.2

–0.1

0

0.1

0.2

30mV/dB

Figure 45. Linear-in-dB Gain Control Response of the X-AMP VGA

Showing Consistent Slope and Low Error

OUTPUT BUFFERS/ADC DRIVERS The low impedance (20 Ω) output buffers of the ADRF6510 are designed to drive either ADC inputs or subsequent amplifier stages. They are capable of delivering up to 4 V p-p composite two-tone signals into 500 Ω differential loads with >60 dBc IM3. The output common-mode voltage defaults to VPS/2, but it can be adjusted from 1.5 V to 3.0 V without loss of drive capability by presenting the VOCM pin with the desired common-mode voltage. The high input impedance of VOCM allows the ADC reference output to be connected directly. Even though the signal path is fully dc-coupled and the dc offset compensation loop can remove undesired dc offsets (see the DC Offset Compensation Loop section), the output buffers can be ac-coupled to the next stage by properly selecting the coupling capacitors according to the load impedance.

DC OFFSET COMPENSATION LOOP In many signal processing applications, no information is carried in the dc level. In fact, dc voltages and other low frequency disturbances can often dominate the intended signal and consume precious dynamic range in the analog path and bits in the data converters. These dc voltages can be present with the desired input signal or can be generated inside the signal path by inherent dc offsets or other unintended signal-dependent processes such as self-mixing or rectification.

Because the ADRF6510 is fully dc-coupled, it may be necessary to remove these offsets to realize the maximum signal-to-noise ratio (SNR). This can be achieved with ac-coupling capacitors at the input and output pins, but that requires large values because the impedances are fairly low, and high-pass corners may need to be <10 Hz in some cases. To address the issue of dc offsets, the ADRF6510 provides an offset correction loop that nulls the output differential dc level as shown in Figure 46. If the correction loop is not required, it can be disabled through the OFDS pin.

GAIN

FROMFILTERS

COFSOFSxOFDS

50dBVGA

OUTPUT ADCDRIVER

BASEBANDOUTPUT

09002-066

Figure 46. Offset Compensation Loop Operation around the VGA

and Output Buffer

The offset control loop creates a high-pass corner, fHP, that is superimposed on the normal Butterworth filter response. Typically, fHP is many orders of magnitude lower than the lower programmed filter bandwidth so that there is no interaction between them. Setting fHP is accomplished with capacitors, COFS, from the OFS1 and OFS2 pins to ground. Because the correction loop works around the VGA section, fHP is also dependent on the gain of the VGA. In general, the expression for fHP is given by

fHP (Hz) = 1.2 × (Gain/COFS)

where: Gain is expressed in linear terms, not in decibels (dB). COFS is expressed in microfarads (µF).

Note that fHP increases in proportion to the gain. For this reason, COFS should be chosen at the highest operating gain to guarantee that fHP is always below the maximum limit required by the system.

Data Sheet ADRF6510

Rev. B | Page 17 of 32

PROGRAMMING THE FILTERS The 0.5 dB corner frequencies for both filters are programmed simultaneously through the SPI port. A 5-bit register stores the codes for corner frequencies of 1 MHz through 30 MHz (see Table 4). The SPI protocol not only allows frequency codes to be written to the DATA pin but also allows the stored code to be read back from the SDO pin.

The latch enable (LE) pin must first go to a Logic 0 for a read or write cycle to begin. On the next rising edge of the clock (CLK), a Logic 1 on the DATA pin initiates a write cycle, whereas a Logic 0 on the DATA pin initiates a read cycle. In a write cycle, the next five CLK rising edges latch the frequency code, LSB first. When LE goes high, the write cycle is completed and the frequency code is presented to the filter. In a read cycle, the next five CLK falling edges present the stored frequency code, LSB first. When LE goes high, the read cycle is completed. Detailed timing diagrams are shown in Figure 2 and Figure 3.

Table 4. Frequency Code vs. Corner Frequency Lookup Table 5-Bit Binary Frequency Code1 Corner Frequency (MHz) 00000 1 00001 2 00010 3 00011 4 00100 5 00101 6 00110 7 00111 8 01000 9 01001 10 01010 11 01011 12 01100 13 01101 14 01110 15 01111 16 10000 17 10001 18 10010 19 10011 20 10100 21 10101 22 10110 23 10111 24 11000 25 11001 26 11010 27 11011 28 11100 29 11101 30 11110 30 11111 30 1 MSB first.

NOISE CHARACTERISTICS The output noise behavior of the ADRF6510 depends on the gain and bandwidth settings. Both the filter sections and the VGAs contribute to the total noise at the output. The filter contributes a noise spectral density profile that is flat at low frequencies, peaks near the corner frequency, and then rolls off as the filter poles roll off the gain. The magnitude of the noise spectral density, expressed in nV/√Hz, varies inversely with the square root of the bandwidth setting, resulting in a total integrated noise in nV that is nearly constant with bandwidth setting.

The X-AMP type VGAs used in the ADRF6510 contribute a fixed noise spectral density to the output, independent of the gain setting, of −130 dBV/√Hz, which is equivalent to 316 nV/√Hz. Although the VGA noise contribution to the output is fixed, the gain of the VGA controls the relative contribution of the filter noise.

Figure 47 and Figure 48 show the total output noise spectral density vs. frequency for different bandwidth settings. At low values of VGA gain, the noise at the output is the flat spectral density contributed by the VGA because the filter noise is sup-pressed by the VGA attenuation. As the gain increases, more of the filter noise appears at the output. Because the filter noise increases at lower bandwidth settings, it overwhelms the VGA noise floor. In either case, the noise density asymptotically approaches the −130 dBV/√Hz limit set by the VGA at the highest frequencies. For other values of VGA gain and band-width setting, the detailed shape of the noise spectral density changes.

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OU

TPU

T N

OIS

E (d

BV/

√Hz)

FREQUENCY (MHz) 09002-046

25 30 35 40 45 50 55

BANDWIDTH = 20MHz

GAIN = 20dB

GAIN = 0dB

GAIN = 40dB

Figure 47. Total Output Noise with a 20 MHz Corner Frequency

for Three Different Gain Settings

ADRF6510 Data Sheet

Rev. B | Page 18 of 32

–100

–1350.5 1.0 1.5 2.0 2.5 3.0

OU

TPU

T N

OIS

E (d

BV/

√Hz)

FREQUENCY (MHz) 09002-047

–130

–125

–120

–115

–110

–105BANDWIDTH = 1MHz

GAIN = 40dB

GAIN = 20dB

GAIN = 0dB

Figure 48. Total Output Noise with a 1 MHz Corner Frequency

for Three Different Gain Settings

Note that the noise spectral density outside the filter bandwidth is limited by the fixed VGA output noise. It may be necessary to use an external, fixed-frequency, passive filter prior to an analog-to-digital conversion to prevent noise aliasing from degrading the signal-to-noise ratio. The higher the sampling rate relative to the maximum ADRF6510 corner frequency setting to be used, the lower the order of the external filter.

DISTORTION CHARACTERISTICS The distortion performance of the ADRF6510 is similar to its noise performance. The filters and the VGAs contribute to the overall distortion and signal handling capabilities. Furthermore, the front end must also cope with out-of-band signals that can be larger than the in-band signals. These out-of-band signals are filtered before reaching the VGA. It is important to understand the signals presented to the ADRF6510 and to match these signals with the input and output characteristics of the part.

When the gain is low, the distortion is typically limited by the input section because the output is not driven to its maximum capacity. When the gain is high, the distortion is likely limited by the output section because the input is not driven to its maximum capacity. An exception to this is when the input is driven with a small desired signal in combination with a large out-of-band signal. In this case, the out-of-band signal may drive the input to distort. As long as the input is not overdriven, the out-of-band signal is removed by the filter. A high VGA gain is still needed to raise the small desired signal to a higher level at the output. The overall distortion introduced by the part depends on the input drive level, including the out-of-band signals, and the desired output signal level.

As noted in the Input Buffers section, the input section can handle a total signal level of 1 V p-p for a 6 dB preamplifier and 500 mV p-p for a 12 dB preamplifier with >50 dBc harmonic distortion. This includes both in-band and out-of-band signals.

To distinguish and quantify the distortion performance of the input section, two different IP3 specifications are presented. The first is called in-band IP3 and refers to a two-tone test where the signals are inside the filter bandwidth. This is exactly the same figure of merit familiar to communications engineers in which the third-order intermodulation level, IM3, is measured.

To quantify the effect of out-of-band signals, a new out-of-band (OOB) IIP3 figure of merit is introduced. This test also involves a two-tone stimulus; however, the two tones are placed out-of-band so that the lower IM3 product lands in the middle of the filter pass band. At the output, only the IM3 product is visible because the original two tones are filtered out. To calculate the OOB IP3 at the input, the IM3 level is referred to the input by the overall gain. The OOB IIP3 allows the user to predict the impact of out-of-band blockers or interferers at an arbitrary signal level on the in-band performance. The ratio of the desired input signal level to the input-referred IM3 at a given blocker level represents a signal-to-distortion limit imposed by the out-of-band signals.

MAXIMIZING THE DYNAMIC RANGE The role of the ADRF6510 is to increase the level of a variable in-band signal while minimizing out-of-band signals. Ideally, this is achieved without degrading the SNR of the incoming signal or introducing distortion to the incoming signal.

The first goal is to maximize the output signal swing, which can be defined by the ADC input range or the input signal capacity of the next analog stage. For the complex waveforms often encoun-tered in communication systems, the peak-to-average ratio, or crest factor, must be considered when choosing the peak-to-peak output. From the chosen output signal and the maximum gain of the ADRF6510, the minimum input level can be defined. Lower signal levels do not yield the maximum output and suffer a greater degradation in SNR.

As the input signal level increases, the VGA gain is reduced from its maximum gain point to maintain the desired fixed output level. The output noise, initially dominated by the filter, follows the gain reduction, yielding a progressively better SNR. At some point, the VGA gain drops sufficiently that the constant VGA noise becomes dominant, resulting in a constant SNR from that point. From the perspective of SNR alone, the maximum input level is reached when the VGA reaches its minimum gain.

Distortion must also be considered when maximizing the dynamic range. At low and moderate signal levels, the output distortion is constant and assumed to be adequate for the selected output level. At some point, the input signal becomes large enough that distortion at the input limits the system. The maximum tolerable input signal depends on whether the input distortion becomes unacceptably large or the minimum gain is reached.

Data Sheet ADRF6510

Rev. B | Page 19 of 32

The most challenging scenario in terms of dynamic range is the presence of a large out-of-band blocker accompanying a weaker in-band wanted signal. In this case, the maximum input level is dictated by the blocker and its inclination to cause distortion. After filtering, the weak wanted signal must be amplified to the desired output level, possibly requiring maximum gain. Both the distortion limits associated with the blocker at the input and the SNR limits created by the weaker signal and higher gains are present simultaneously. Furthermore, not only does the blocker scenario degrade the dynamic range but it also reduces the range of input signals that can be handled because a larger part of the gain range is used to simply extract the weak desired signal from the stronger blocker.

KEY PARAMETERS FOR QUADRATURE-BASED RECEIVERS The majority of digital communication receivers makes use of quadrature signaling, in which bits of information are encoded onto pairs of baseband signals that then modulate in-phase (I)

and quadrature (Q) sinusoidal carriers. Both the baseband and modulated signals appear quite complex in the time domain with dramatic peaks and valleys. In a typical receiver, the goal is to recover the pair of quadrature baseband signals in the presence of noise and interfering signals after quadrature demodulation. In the process of filtering out-of-band noise and unwanted inter-ferers and restoring the levels of the wanted I and Q baseband signals, it is critical to retain their gain and phase integrity over the bandwidth.

The ADRF6510 delivers flat in-band gain and group delay, consistent with a six-pole Butterworth prototype filter as described in the Programmable Filters section. Furthermore, careful design ensures excellent matching of these parameters between the I and Q channels. Although absolute gain flatness and group delay can be corrected with digital equalization, mismatch introduces quadrature errors and intersymbol inter-ference that degrade bit error rates in digital communication systems.

ADRF6510 Data Sheet

Rev. B | Page 20 of 32

APPLICATIONS INFORMATION BASIC CONNECTIONS Figure 49 shows the basic connections for operating the ADRF6510. A voltage from 4.75 V to 5.25 V should be applied to the supply pins. Each supply pin should be decoupled with at least one low inductance, surface-mount ceramic capacitor of 0.1 µF placed as close as possible to the device.

The input buffers provide an interface to the sensitive filter sections that follow. They set a differential input impedance of 400 Ω and sit at a nominal common-mode voltage of VPS/2. The inputs can be dc-coupled or ac-coupled. If using direct dc-coupling, the common-mode voltage, VCM, can range from 1.5 V to 3 V.

The output buffers of the ADRF6510 are low impedance (~20 Ω) designed to drive either ADC inputs or subsequent amplifier stages. The output common-mode voltage defaults to VPS/2 but can be adjusted from 1.5 V to 3.0 V without loss of drive capability by presenting the VOCM pin with the desired common-mode voltage. The high input impedance of VOCM allows the ADC reference output to be connected directly.

To enable the ADRF6510, the ENBL pin must be pulled high. Taking ENBL low disables the device, reducing current con-sumption to approximately 2 mA at ambient temperature.

ERROR VECTOR MAGNITUDE (EVM) PERFORMANCE Error vector magnitude (EVM) is a measure used to quantify the performance of a digital radio transmitter or receiver by measuring the fidelity of the digital signal transmitted or received. Various imperfections in the link, such as magnitude and phase imbalance, noise, and distortion, cause the constel-lation points to deviate from their ideal locations.

In general, a receiver exhibits three distinct EVM limitations vs. received input signal power. As signal power increases, the distortion components increase.

• At large enough signal levels, where the distortion compo-nents due to the harmonic nonlinearities in the devicedominate, EVM degrades as signal levels increase.

• At medium signal levels, where the signal chain behavesin a linear manner and the signal is well above any notablenoise contributions, EVM has a tendency to reach anoptimal level determined dominantly by either thequadrature accuracy and I/Q gain match of the signalchain or the precision of the test equipment.

• As signal levels decrease, such that noise is a major con-tributor, EVM performance vs. the signal level exhibitsa decibel-for-decibel degradation with decreasing signallevels. At these lower signal levels, where noise is thedominant limitation, decibel EVM is directly proportionalto the SNR.

VPSD

COMD

LE

CLK

DATA

SDO

COM

VPS

OPP1

OPM1

COM

GAIN

VOCM

COM

OPM2

OPP2

COMINP2

INM2VPS

COMOFDS

OFS2VPS

ENBLINP1

INM1VPS

COMGNSW

OFS1VPS

ADRF6510

VPSD

LECLK

DATASDO

INP2

INM2

VPS

VPS

OPP2

INM1

INP1

09002-050

OPM1

OPM2

OPP1

VPS

VPS

VPS

VPS

VPS

VPS

VPS

VPS

Figure 49. Basic Connections

Data Sheet ADRF6510

Rev. B | Page 21 of 32

EVM The basic setup to test EVM for the ADRF6510 consisted of an Agilent E4438C used as a RF signal source with an Agilent InfiniiVision DSO7104B oscilloscope in conjunction with the Agilent 89600 VSA software to sample the signal and compute the EVM. The E4438C RF output drove the RF port of the ADL5380 IQ demodulater, which in turn drove the baseband differential inputs of the ADRF6510.

The I and Q outputs of the ADRF6510 were taken differentially into two AD8130 difference amplifiers to convert them into single-ended signals. The single-ended signals were connected to the input channels of the oscilloscope, which captured the modulated waveforms.

An overall baseband EVM performance was measured on the ADRF6510. A modulation setting of 4 QAM and, unless otherwise noted, a 5 MHz symbol rate were used, with a pulse shaping filter alpha of 0.35. The analog gain of the ADRF6510 was adjusted to maintain 1.5 V p-p into a 1 kΩ differential load impedance. Figure 50 shows EVM vs. input power for three different IF frequencies. The input power is the integrated input power over the bandwidth of the modulated signal.

In Figure 50, the ADRF6510 shows excellent EVM of better than −-35 dB over a 50 dB range at a 0Hz IF. The user can chose to use a complex IF of 5 MHz to achieve even a better EVM of at least −40 dB over a 50 dB range.

0

–80 –10 0 10

EVM

(dB

)

PIN (dBm) 09002-058

–5

–10

–15

–20

–25

–30

–35

–40

–45

–50–50–60–70 –40 –30 –20

0Hz IF

2.5MHz IF

5MHz IF

Figure 50. EVM vs. RF Input Power Level; OFDS Pulled Low, COFS = 1 µF

EFFECT OF FILTER BANDWIDTH ON EVM Care should be taken when selecting the filter bandwidth. In a digital transceiver, the modulated signal is filtered by a pulse shaping filter (such as a root-raised cosine filter) at both the transmit and receive ends to guard against intersymbol inter-ference (ISI). If additional filtering of the modulated signal is done, the signal must be within the pass band of the filter. When the corner frequency of the ADRF6510 filter begins to encroach on the modulated signal, ISI is introduced and degrades EVM, which can lead to loss of signal lock.

While low-pass filtering with the ADRF6510 to reject out-of-band undesired signals (blockers), more rejection of the undesired signals may be required. If the filter bandwidth is set to approximately the same as the signal bandwidth, the user may trade some degradation of EVM for a gain in rejection of the out-of-band undesired signals, by lowering the low-pass filter bandwidth corner (for example, by 1 MHz).

Lowering the filter bandwidth to gain more rejection works progressively better the lower the signal and filter bandwidths are set to (see Figure 43). A 1 MHz change from 3 MHz filter bandwidth to 2 MHz filter bandwidth yields about 20 dB more rejection. Compare that to a 1 MHz change from 29 MHz filter band-width to 28 MHz filter bandwidth, which will yield about 1 dB more in rejection.

Figure 51 shows that degradation of EVM as signal bandwidth (positive frequency only) is swept while keeping the filter bandwidth set to 5 MHz. Three different COFS capacitor values were used.

0

0 1412108642

EVM

(dB

)

SIGNAL BANDWIDTH (MHz) 09002-151

–5

–10

–15

–20

–25

–30

–35

–40COFS = 1µF

COFS = 100nF

COFS = 1nF

FILTER BW CORNER

Figure 51. EVM vs. Signal Bandwidth over COFS Values While Maintaining a

Filter Bandwidth of 5 MHz

EFFECT OF OUTPUT VOLTAGE LEVELS ON EVM Output voltage level can affect EVM greatly when the signal is compressed. When changing the output voltage levels of

the ADRF6510, take care that the output signal is not in compression, which causes EVM degradation.

ADRF6510 Data Sheet

Rev. B | Page 22 of 32

0

–80 –70 –60 –50 –40 –30 –20 –10 0 10

EVM

(dB

)

PIN (dBm) 09002-152

–5

–10

–15

–20

–25

–30

–40

–35

–50

–45

750mV p-p1.50V p-p1.75V p-p2.00V p-p2.25V p-p2.90V p-p2.95V p-p

Figure 52. EVM vs. RF Input Power over Output Voltage Levels,

IF = 5 MHz, OFDS Pulled High

Figure 52 shows EVM degradation as the signal level nears compression. At 2.25 V p-p the signal is already degraded a few decibels. When the output level is near the absolute limits of the output stage, the EVM becomes much more erratic over the RF input power level.

EFFECT OF COFS ON EVM When enabled, the dc offset compensation loop effectively nulls any information below the high-pass corner set by the COFS capacitor. However, loss of the low frequency information of the modulated signal can degrade the EVM in some cases.

As the signal bandwidth becomes larger, the percentage of information that is corrupted by the high-pass corner becomes smaller. In such cases, it is important to select a COFS capacitor large enough to minimize the high-pass corner frequency, which prevents loss of information and degraded EVM.

Figure 53 shows the effect of COFS values at a single signal bandwidth of 6.75 MHz = 1.35 × 5 MHz over input power.

Figure 54 shows that EVM can be improved by using a bigger COFS value and/or increasing the signal bandwidth. Increasing signal bandwidth will improve EVM to a point after which the bandwidth limitations of the source, the part, and/or the receiver will start to dominate and degrade EVM.

0

–80 –70 –60 –50 –40 –30 –20 –10 0 10

EVM

(dB

)

PIN (dBm) 09002-153

–5

–10

–15

–20

–25

–30

–40

–35

–50

–45

COFS = 1µF

COFS = 100nF

COFS = 1nF

Figure 53. EVM vs. RF Input Power over COFS Values

0

0 3530252015105

EVM

(dB

)

SIGNAL BANDWIDTH (MHz) 09002-154

–5

–10

–15

–20

–25

–30

–40

–35

–45

COFS = 1µF

COFS = 100nF

COFS = 1nF

Figure 54. EVM vs. Signal BW over COFS Values

ANTI-ALIASING FILTER The noise spectral density of the ADRF6510 outside the filter bandwidth is limited by the fixed VGA output noise. It may be necessary to use an external, fixed-frequency, passive filter prior to an analog-to-digital conversion to prevent noise aliasing from degrading the signal-to-noise ratio. As shown in Figure 47 and Figure 48, the noise density at higher frequencies tends to be flat, and any higher IF noise aliasing into the Nyquist zone has minimal effects.

When designing an antialiasing filter, it is necessary to consider the overall source and load impedance presented by the ADRF6510 and the ADC input to design the filter network. The differential baseband output impedance of the ADRF6510 is 20 Ω and is designed to drive a high impedance ADC input. It may be desirable to terminate the ADC input to a lower imped-ance by using a terminating resistor, such as 500 Ω. The terminating resistor helps to better define the input impedance at the ADC input at the cost of a slightly reduced gain.

The order and type of filter network depend on the desired high frequency rejection required, the pass-band ripple, and the group delay. Filter design tables provide outlines for various filter types and orders, illustrating the normalized inductor and capacitor values for a 1 Hz cutoff frequency and 1 Ω load.

After scaling the normalized prototype element values by the actual desired cutoff frequency and load impedance, the series reactance elements are halved to realize the final balanced filter network component values.

As an example, a second-order Butterworth, low-pass filter design is shown in Figure 55 where the differential load impedance is 500 Ω and the source impedance is 50 Ω. The normalized series inductor value for the 10-to-1, load-to-source impedance ratio is 0.074 H, and the normalized shunt capacitor is 14.814 F. For a 31 MHz cutoff frequency, the single-ended equivalent circuit consists of a 0.191 µH series inductor followed by a 152 pF shunt capacitor.

Data Sheet ADRF6510

Rev. B | Page 23 of 32

The balanced configuration is realized as the 0.191 µH inductor is split in half to achieve the network that is shown in Figure 55.

VS

RS2

RSRL

RS2

RL2

RL2

152pF

VS

RS = 50Ω

RL = 500Ω

0.191µH

0.096µH

0.096µH

152pF

BALANCEDCONFIGURATION

DENORMALIZEDSINGLE-ENDEDEQUIVALENT

VS

RS = 0.1Ω

= 0.1Ω

RL = 1Ω

LN = 0.074H

CN 14.814FNORMALIZED

SINGLE-ENDEDCONFIGURATION

= 25Ω

= 25Ω

= 250Ω

= 250Ω

fC = 31MHz

fC = 1Hz

09002-061

Figure 55. Second-Order Butterworth, Low-Pass Filter Design Example

A complete design example is shown in Figure 56. A third-order Chebyshev differential filter with a 31 MHz corner frequency interfaces the output of the ADRF6510 to that of an ADC input. The 20 Ω source impedance reflects the impedance of the output buffer stage. The 500 Ω load resistor defines the input impedance of the ADC. The filter adheres to a 0.1 dB in-band flatness and offers sufficient out-of-band rejection to act as an antialiasing filter.

1.8µH

1.8µH

15pF

1µH

1µH

500Ω

20Ω

09002-064

Figure 56. Third-Order Chebyshev Differential Filter Design Example

Figure 57 and Figure 58 show the measured frequency response and group delay of the third-order Chebyshev differential filter.

10

–500 20 40 60 80 100 120 140 200180160

GA

IN (d

B)

BASEBAND FREQUENCY (MHz) 09002-048

–45

–40

–35

–30

–25

–20

–15

–10

–5

0

5

Figure 57. Third-Order Baseband Filter Response

20

00 20 40 60 30028026024022020018016014012010080

GR

OU

P D

ELA

Y (n

s)

BASEBAND FREQUENCY (MHz) 09002-049

2

4

6

8

10

12

14

16

18

Figure 58. Third-Order Baseband Filter Group Delay Response

ADRF6510 Data Sheet

Rev. B | Page 24 of 32

EVALUATION BOARD The ADRF6510 evaluation board is available with software control to program the filter bandwidth. It is a 4-layer board with split ground plane for analog and digital sections. Special care is taken to place the power decoupling capacitors close to the device pins. The board is designed for easy single-ended (through a Mini-Circuits® ADT8-1T+ 8:1 balun) or differential configuration for each channel.

EVALUATION BOARD CONTROL SOFTWARE The ADRF6510 evaluation board is configured with a USB-friendly interface to program the filter bandwidth of the ADRF6510. The software GUI (see Figure 59) allows users to select a particular frequency to write to the device and also to read back data from the SDO pin that shows the currently programmed filter setting. The software setup files can be down-loaded from the ADRF6510 product page at www.analog.com.

0900

2-0

51

Figure 59. Evaluation Control Software

SCHEMATICS AND ARTWORK

09

002-

06

5

VPSD

COMD

LE

CLK

DATA

SDO

COM

VPS

OPP1

OPM1

COM

GAIN

VOCM

COM

OPM2

OPP2

COMINP2

INM2VPS

COMOFDS

OFS2VPS

ENBLINP1

INM1VPS

COMGNSW

OFS1VPS

ADRF6510

VPSD

VPS

VPS

VOCM

VPS

VGAIN

VPS

VPS

VPS

VPSR20Ω

INP2

INM2_SE_P

R490Ω

R320Ω

R500Ω

R530Ω

R310kΩ

R50Ω

R60Ω

R15OPEN

R46OPEN

R16OPEN

R44OPEN

R51OPEN

R52OPEN R54

C7100nFC3

0.1µF

C40.1µF

C50.1µF

C150.1µF

C170.1µF

C180.1µF

VGAIN

VOCM

C131000pF

R410kΩ

P3

C160.1µF

C141000pF

C120.1µF

C110.1µF

C8100nF

T11

3

65

4

INP1

INM1_SE_P

R470Ω

R310Ω

R480Ω

R570Ω

R17OPEN

R45OPEN

R18OPEN

R43OPEN

R55OPEN

R56OPEN R58

C9100nFC6

0.1µF

C10100nF

P4T2

1

3

65

4

P2

VPS

LE

CLK

DATA

SDO

R29100Ω

C27330pF

R340Ω

R30100Ω

R330Ω

C27330pF

R110kΩ

T4

1

3

6

54

OPP2

OPM2_SE_P

R420Ω

R350Ω

R9300Ω

R10300Ω

R360Ω

R38OPEN

R23OPEN

R40OPEN

R22OPEN

R14OPEN

R13OPEN

C21100nF

C22100nF

C240.1µF

T3

1

3

6

54

OPP1

OPM1_SE_P

R410Ω

R190Ω

R7300Ω

R8300Ω

R200Ω

R37OPEN

R24OPEN

R39OPEN

R21OPEN

R12OPEN

R11OPEN

C19100nF

C20100nF

C230.1µF

VPOSDIG_VPOS

VPOSD

L233µH

C210µF

C110µF

L133µH

VPOS

COMD COM

NET NAME

TEST POINT

SMA INPUT/OUTPUT

DIGITAL GROUND

ANALOG GROUND

LEGEND

Figure 60. Evaluation Board Schematic

Data Sheet ADRF6510

Rev. B | Page 25 of 32

09002-026

56 55 54 53 52 51 50 49

15 16 17 18 19 20 21 22

1

2

3

4

5

6

7

8 35

36

37

38

39

40

41

42

PD7_

FD15

PD4_

FD12

PD6_

FD14

PD5_

FD13

GN

D

CLK

OU

T

GN

D

VCC

PA5_FIFOARD1

PA2_SLOE

RESET_N

PA3_WU2

PA4_FIFOARD0

PA6_PKTEND

PA7_FLAGD_SCLS_N

GND

DPLUS

XTALOUT

XTALIN

RDY1_SLWR

AVCC

AVCC

AGND

RDY0_SLRD

CY7C68013A-56LTXCU4

LE

9 DMINUS

10 AGND

11 VCC

12 GND

13 IFCLK

14 RESERVED

23 24 2725 26 28

VCC

SDA

PB4_

FD4

PB3_

FD3

PB0_

FD0

SCL

PB1_

FD1

PB2_

FD2

PB5_

FD5

PB6_

FD6

VCC

PB7_

FD7

GN

D

GN

D

29

30

31

32

33

34

CTL1_FLAGB

PA1_INT1_N

CTL0_FLAGA

CTL2_FLAGC

VCC

PA0_INT0_N

48 47 46 45 44 43

WA

KEU

P

VCC

PD0_

FD8

PD1_

FD9

PD3_

FD11

PD2_

FD10

CLK

DATA

SDO

3V3_USB3V3_USB

3V3_USB

C4810pF

C490.1µF

3V3_USB

3V3_USB

R612kΩ

CR2

3V3_USB

R64100kΩ

C370.1µF

C450.1µF

R62100kΩ3V3_USB

Y124 MHz

3

4 2

1

C5422pF

C5122pF

12345G1G2G3G4

5V_USB

P5

1

2

3

4

5

6

7

8

A0

A1

A2

GND

SDA

SCL

WC_N

VCC

3V3_USB

3V3_USB

24LC64-I_SNU2

ADP3334U3

1 8

2

3

4

7

6

5

OUT1

OUT2

FB

NC

IN2

IN1

SD

GND

C471.0µF

R652kΩ

CR1

5V_USB

R6978.7kΩ

C501000pF

R70140kΩC52

1.0µF

3V3_USB

DGND

C350.1µF

C420.1µF

C360.1µF

C410.1µF

C400.1µF

C440.1µF

C460.1µF

3V3_USB

Figure 61. Schematic for the USB Section of the Evaluation Board

ADRF6510 Data Sheet

Rev. B | Page 26 of 32

09002-052

Figure 62. Top Layer Silkscreen

09002-053

Figure 63. Component Side Layout

Data Sheet ADRF6510

Rev. B | Page 27 of 32

EVALUATION BOARD CONFIGURATION OPTIONS Table 5 lists the components of the main section of the ADRF6510 evaluation board.

Table 5. Components Function Default Conditions C1, C2, C4, C5, C11, C12, C15, C16, L1, L2

Power supply and ground decoupling. Nominal supply decoupling consists of a 0.1 µF capacitor to ground.

C1, C2 = 10 µF (Size 1210) C4, C5, C11, C12, C15, C16 = 0.1 µF (Size 0603) L1, L2 = 33 µH (Size 1812) R2 = 0 Ω (Size 0402)

T1, T2, C3, C6, C7 to C10, R15 to R18, R31, R32, R43 to R58

Input interface. Input SMAs INM1_SE_P and INP2_SE_P are used to drive the baluns in a single-ended fashion. The default configuration of the evaluation board is for single-ended operation. T1 and T2 are 8:1 impedance ratio baluns to transform a 50 Ω, single-ended input into a 400 Ω balanced differential signal. R31, R32, and R47 to R50 are populated for appropriate balun interface. R51 to R58 are provided for generic placement of matching components. C3 and C6 are balun decoupling capacitors. R15 to R18 and R43 to R46 can be populated with 0 Ω, and the balun interfacing resistors can be removed to bypass T1 and T2 for differential interfacing. C7 to C10 can be used for ac coupling with differential interfacing.

T1, T2 = ADT8-1T+ (Mini-Circuits) C3, C6 = 0.1 µF (Size 0402) C7 to C10 = 100 nF (Size 0402) R15 to R18, R43 to R46, R51, R52, R55, R56 = open (Size 0402) R31, R32, R47 to R50, R53, R54, R57, R58 = 0 Ω (Size 0402)

T3, T4, C19 to C24, R7 to R14, R19 to R24, R35 to R42

Output interface. Output SMAs OPP1_SE_P and OPM2_SE_P are used to drive the baluns in a single-ended fashion. The default configuration of the evaluation board is for single-ended operation. T3 and T4 are 8:1 impedance ratio baluns to transform a 50 Ω, single-ended output into a 400 Ω balanced differential load. R19, R20, R35, R36, R41, and R42 are populated for appropriate balun interface. R7 to R14 are provided for generic placement of matching components. R7 to R10 are set to 300 Ω to present a 1 kΩ load (with the balun used) at the DUT output. C19 to C22 are used for ac coupling when differential outputs are used. C23 and C24 are balun decoupling capacitors. R21 to R24 and R37 to R40 can be populated with 0 Ω, and the balun interfacing resistors can be removed to bypass T3 and T4 for differential interfacing.

T3, T4 = ADT8-1T+ (Mini-Circuits) C19 to C22 = 100 nF (Size 0402) C23, C24 = 0.1 µF (Size 0402) R7 to R10 = 300 Ω (Size 0402) R11 to R14 = open R19, R20, R35, R36, R41, R42 = 0 Ω (Size 0402) R21 to R24, R37 to R40 = open (Size 0402)

P2 Enable interface. The ADRF6510 is powered up by applying a logic high voltage to the ENBL pin (Jumper P2 is connected to VPS).

P2 = installed for enable

C27, C28, R1, R29, R30, R33, R34

Serial interface control. The digital interface sets the corner frequency of the device using the serial interface via the LE, CLK, DATA, and SDO pins.

R1 = 10 kΩ (Size 0402) C27, C28 = 330 pF (Size 0402) R29, R30 = 100 Ω (Size 0402) R33, R34 = 0 Ω (Size 0402)

P4, C13, C14, R3 DC offset correction loop compensation. The dc offset correction loop is enabled (low) with Jumper P4. When enabled, the capacitors are connected to circuit common. The high-pass corner frequency is expressed as follows: fHP (Hz) = 1.2 × ((Linear Gain)/COFS (µF)).

P4 = installed C13, C14 = 1000 pF (Size 0402) R3 = 10 kΩ (Size 0402)

C18, R6 Output common-mode setpoint. The output common-mode voltage can be set externally when applied to the VOCM pin. If the VOCM pin is left open, the output common-mode voltage defaults to VPS/2.

C18 = 0.1 µF (Size 0402) R6 = 0 Ω (Size 0402)

C17, R5 Analog gain control. 0 V to 2 V, 30 mV/dB gain scaling. C17 = 0.1 µF (Size 0402) R5 = 0 Ω (Size 0402)

P3, R4 Front-end 6 dB or 12 dB gain switch. Pull low for 6 dB; pull high for 12 dB. P3 = installed R4 = 10 kΩ (Size 0402)

ADRF6510 Data Sheet

Rev. B | Page 28 of 32

USB Section Configuration Options

Table 6 lists the components of the USB section of the ADRF6510 evaluation board.

Table 6. Components Default Conditions XC1, XC2, XC6 22 pF (Size 0603) XC3 to XC5, XC7, XC8, XC12 to XC19 0.1 µF (Size 0402) XC9 to XC11 10 pF (Size 0402) XD1 Green LED ( Panasonic LNJ308G8TRA) XJ1 USB SMT connector (Hirose Electric UX60A-MB-5ST 240-0003-4) XR1, XR2 2 kΩ (Size 0603) XR3 1 kΩ (Size 0603) XR4, XR5 100 kΩ (Size 0603) XR6 0 Ω (Size 0603) XU1 USB microcontroller (Cypress CY7C68013A-56LFXC) XU2 64 kb EEPROM (Microchip 24LC64-I/SN) XU3 Low dropout regulator (Analog Devices ADP3303ARZ-3.3) XY1 24 MHz crystal oscillator (AEL Crystals X24M000000S244)

Data Sheet ADRF6510

Rev. B | Page 29 of 32

OUTLINE DIMENSIONS

3.253.10 SQ2.95

0.800.750.70

1

0.50BSC

BOTTOM VIEWTOP VIEW

PIN 1INDICATOR

32

916

17

24

25

8

0.05 MAX0.02 NOM

0.20 REF

COPLANARITY0.08

0.300.250.18

5.105.00 SQ4.90

0.500.400.30

0.25 MIN

02-2

2-20

17-A

COMPLIANT TO JEDEC STANDARDS MO-220-WHHDPKG

-003

898

SEATINGPLANE

EXPOSEDPAD

SIDE VIEW

PIN 1INDIC ATOR AREA OPTIONS(SEE DETAIL A)

DETAIL A(JEDEC 95)

FOR PROPER CONNECTION OFTHE EXPOSED PAD, REFER TOTHE PIN CONFIGURATION ANDFUNCTION DESCRIPTIONSSECTION OF THIS DATA SHEET.

Figure 64. 32-Lead Lead Frame Chip Scale Package [LFCSP]

5 mm × 5 mm Body and 0.75 mm Package Height (CP-32-7)

Dimensions shown in millimeters

ORDERING GUIDE Model1 Temperature Range Package Description Package Option ADRF6510ACPZ-R7 −40°C to +85°C 32-Lead LFCSP, 7” Tape and Reel CP-32-7 ADRF6510-EVALZ Evaluation Board 1 Z = RoHS Compliant Part.

ADRF6510 Data Sheet

Rev. B | Page 30 of 32

NOTES

Data Sheet ADRF6510

Rev. B | Page 31 of 32

NOTES

ADRF6510 Data Sheet

Rev. B | Page 32 of 32

NOTES

©2010-2017 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners.

D09002-0-9/17(B)