Analog Devices AD9287 Service Manual

Quad, 8-Bit, 100 MSPS

A

V

W

FEATURES

4 ADCs integrated into 1 package 133 mW ADC power per channel at 100 MSPS SNR = 49 dB (to Nyquist) ENOB = 7.85 bits SFDR = 65 dBc (to Nyquist) Excellent linearity

DNL = ±0.2 LSB (typical) INL = ±0.2 LSB (typical)

Serial LVDS (AN SI-644, default)

Low power, reduced signal option (similar to IEEE 1596.3) Data and frame clock outputs 295 MHz full-power analog bandwidth 2 V p-p input voltage range

1.8 V supply operation Serial port control

Full-chip and individual-channel power-down modes

Flexible bit orientation

Built-in and custom digital test pattern generation

Programmable clock and data alignment

Programmable output resolution

Standby mode

APPLICATIONS

Medical imaging and nondestructive ultrasound Portable ultrasound and digital beam-forming systems Quadrature radio receivers Diversity radio receivers Tap e dr ive s Optical networking Test equipment

GENERAL DESCRIPTION

The AD9287 is a quad, 8-bit, 100 MSPS analog-to-digital converter (ADC) with an on-chip sample-and-hold circuit designed for low cost, low power, small size, and ease of use. The product operates at a conversion rate of up to 100 MSPS and is optimized for outstanding dynamic performance and low power in applications where a small package size is critical.

The ADC requires a single 1.8 V power supply and LVPECL-/ CMOS-/LVDS-compatible sample rate clock for full performance operation. No external reference or driver components are required for many applications.

The ADC automatically multiplies the sample rate clock for the appropriate LVDS serial data rate. A data clock output (DCO) for

Rev. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her 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.

Serial LVDS 1.8 V A/D Converter

AD9287

FUNCTIONAL BLOCK DIAGRAM

DD

VIN + A

VIN – A

VIN + B

VIN – B

VIN + C

VIN – C

VIN + D

VIN – D

VREF

SENSE

REFT

REFB

SELECT

REF

+ –

AGND

capturing data on the output and a frame clock output (FCO) for signaling a new output byte are provided. Individual-channel power-down is supported and typically consumes less than 2 mW when all channels are disabled.

The ADC contains several features designed to maximize flexibility and minimize system cost, such as programmable clock and data alignment and programmable digital test pattern generation. The available digital test patterns include built-in deterministic and pseudorandom patterns, along with custom userdefined test patterns entered via the serial port interface (SPI).

The AD9287 is available in a RoHS compliant, 48-lead LFCSP. It is specified over the industrial temperature range of −40°C to +85°C.

PRODUCT HIGHLIGHTS

1. Small Footprint. Four ADCs are contained in a small, space-

saving package.

2. Low power of 133 mW/channel at 100 MSPS.

3. Ease of Use. A data clock output (DCO) is provided that

operates at frequencies of up to 400 MHz and supports double data rate (DDR) operation.

4. User Flexibility. SPI control offers a wide range of flexible

features to meet specific system requirements.

5. Pin-Compatible Family. This includes the AD9219 (10-bit),

AD9228 (12-bit), and AD9259 (14-bit).

PD

AD9287

T/H

0.5V

SERIAL PORT

INTERFACE

CSB

SDIO/ODMRBIAS

N

Figure 1.

PIPELINE

ADC

PIPELINE

ADC

PIPELINE

ADC

PIPELINE

ADC

SCLK/DTP

DRVDD

8

SERIAL

8

SERIAL

8

SERIAL

8

SERIAL

DATA RATE

MULTIPLIER

CLK+

DRGND

LVDS

CLK–

D + A D – A

D + B D – B

D + C D – C

D + D D – D

FCO+

FCO–

DCO+ DCO–

05966-001

AD9287

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications....................................................................................... 1

General Description......................................................................... 1

Functional Block Diagram .............................................................. 1

Product Highlights........................................................................... 1

Revision History ............................................................................... 2

Specifications..................................................................................... 3

AC Specifications.......................................................................... 4

Digital Specifications ................................................................... 5

Switching Specifications .............................................................. 6

Timing Diagrams.............................................................................. 7

Absolute Maximum Ratings............................................................ 9

Thermal Impedance..................................................................... 9

ESD Caution.................................................................................. 9

Pin Configuration and Function Descriptions........................... 10

Analog Input Considerations ................................................... 18

Clock Input Considerations...................................................... 20

Serial Port Interface (SPI).............................................................. 28

Hardware Interface..................................................................... 28

Memory Map .................................................................................. 30

Reading the Memory Map Table.............................................. 30

Reserved Locations .................................................................... 30

Default Values............................................................................. 30

Logic Levels................................................................................. 30

Evaluation Board ............................................................................ 34

Power Supplies ............................................................................ 34

Input Signals................................................................................ 34

Output Signals ............................................................................ 34

Default Operation and Jumper Selection Settings................. 35

Alternative Analog Input Drive Configuration...................... 36

Equivalent Circuits......................................................................... 12

Typical Performance Characteristics ........................................... 14

Theory of Operation ...................................................................... 18

REVISION HISTORY

5/07—Rev. 0 to Rev. A

Changes to Logic Output (SDIO/ODM)....................................... 5

Change to Pipeline Latency............................................................. 6

Added Endnote 2 to Table 4 ............................................................ 6

Changes to Figure 2 to Figure 4...................................................... 7

Changes to Figure 10...................................................................... 12

Change to Figure 15 Caption........................................................ 14

Changes to Figure 29...................................................................... 16

Changes to Figure 41...................................................................... 19

Changes to Clock Duty Cycle Considerations Section.............. 20

Changes to Power Dissipation and Power-Down Mode Section ...21

Changes to Figure 50 to Figure 52 Captions............................... 23

Change to Table 8 ........................................................................... 23

Changes to Table 9 Endnote.......................................................... 24

Changes to Digital Outputs and Timing Section ....................... 25

Added Table 10 ............................................................................... 25

Changes to RBIAS Pin Section ..................................................... 26

Outline Dimensions ....................................................................... 50

Ordering Guide .......................................................................... 50

Deleted Figure 53 and Figure 54 .................................................. 26

Changes to Figure 56...................................................................... 27

Changes to Hardware Interface Section ...................................... 28

Added Figure 57 ............................................................................. 29

Changes to Table 15 ....................................................................... 29

Changes to Reading the Memory Map Table Section ............... 30

Changes to Output Signals Section.............................................. 34

Changes to Figure 60...................................................................... 34

Changes to Default Operation and

Jumper Selection Settings Section........................................... 35

Changes to Alternative Analog Input Drive

Configuration Section............................................................... 36

Changes to Figure 63...................................................................... 38

Changes to Table 17 ....................................................................... 46

Changes to Ordering Guide.......................................................... 50

7/06—Revision 0: Initial Version

Rev. A | Page 2 of 52

AD9287

SPECIFICATIONS

AVDD = 1.8 V, DRVDD = 1.8 V, 2 V p-p differential input, 1.0 V internal reference, AIN = −0.5 dBFS, unless otherwise noted.

Table 1.

Parameter

1

Temp Min Typ Max Unit

RESOLUTION 8 Bits ACCURACY

No Missing Codes Full Guaranteed Offset Error Full ±5 ±23.4 mV Offset Matching Full ±5 ±23.4 mV Gain Error Full ±6 % FS Gain Matching Full ±0.5 ±2 % FS Differential Nonlinearity (DNL) Full ±0.2 ±0.8 LSB Integral Nonlinearity (INL) Full ±0.2 ±0.65 LSB

TEMPERATURE DRIFT

Offset Error Full ±2 ppm/°C Gain Error Full ±17 ppm/°C Reference Voltage (1 V Mode) Full ±21 ppm/°C

REFERENCE

Output Voltage Error (V Load Regulation at 1.0 mA (V

= 1 V) Full ±5 ±30 mV

REF

= 1 V) Full 3 mV

REF

Input Resistance Full 6 kΩ

ANALOG INPUTS

Differential Input Voltage (V

= 1 V) Full 2 V p-p

REF

Common-Mode Voltage Full AVDD/2 V Differential Input Capacitance Full 7 pF Analog Bandwidth, Full Power Full 295 MHz

POWER SUPPLY

AVDD Full 1.7 1.8 1.9 V DRVDD Full 1.7 1.8 1.9 V I

AVDD

I

DRVDD

Full 260 274 mA

Full 34.5 38 mA Total Power Dissipation (Including Output Drivers) Full 530 562 mW Power-Down Dissipation Full 2 4 mW Standby Dissipation

2

Full 72 mW

CROSSTALK Full −100 dB CROSSTALK (Overrange Condition)

1

See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.

2

Can be controlled via the SPI.

3

Overrange condition is specific with 6 dB of the full-scale input range.

3

Full −100 dB

Rev. A | Page 3 of 52

AD9287

AC SPECIFICATIONS

AVDD = 1.8 V, DRVDD = 1.8 V, 2 V p-p differential input, 1.0 V internal reference, AIN = −0.5 dBFS, unless otherwise noted.

Table 2.

Parameter

1

Temp Min Typ Max Unit

SIGNAL-TO-NOISE RATIO (SNR)

fIN = 2.4 MHz Full 49.2 dB fIN = 49.7 MHz Full 46.5 49.0 dB fIN = 70 MHz Full 49.0 dB

SIGNAL-TO-NOISE AND DISTORTION RATIO (SINAD)

fIN = 2.4 MHz Full 49.0 dB fIN = 49.7 MHz Full 46.0 48.5 dB fIN = 70 MHz Full 48.5 dB

EFFECTIVE NUMBER OF BITS (ENOB)

fIN = 2.4 MHz Full 7.88 Bits fIN = 49.7 MHz Full 7.43 7.85 Bits fIN = 70 MHz Full 7.85 Bits

SPURIOUS-FREE DYNAMIC RANGE (SFDR)

fIN = 2.4 MHz Full 70.0 dBc fIN = 49.7 MHz Full 54.0 65.0 dBc fIN = 70 MHz Full 62.0 dBc

WORST HARMONIC (Second or Third)

fIN = 2.4 MHz Full −70.0 dBc fIN = 49.7 MHz Full −65.0 −54.0 dBc fIN = 70 MHz Full −62.0 dBc

WORST OTHER (Excluding Second or Third)

fIN = 2.4 MHz Full −77.0 dBc fIN = 49.7 MHz Full −74.0 −58.5 dBc fIN = 70 MHz Full −71.0 dBc

TWO-TONE INTERMODULATION DISTORTION (IMD)—

AIN1 AND AIN2 = −7.0 dBFS f

= 15 MHz,

IN1

f

= 16 MHz

IN2

f

= 70 MHz,

IN1

= 71 MHz

f

IN2

1

See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.

25°C 70.0 dBc

25°C 68.5 dBc

Rev. A | Page 4 of 52

AD9287

DIGITAL SPECIFICATIONS

AVDD = 1.8 V, DRVDD = 1.8 V, 2 V p-p differential input, 1.0 V internal reference, AIN = −0.5 dBFS, unless otherwise noted.

Table 3.

Parameter

1

Temp Min Typ Max Unit

CLOCK INPUTS (CLK+, CLK−)

Logic Compliance CMOS/LVDS/LVPECL Differential Input Voltage

2

Full 250 mV p-p Input Common-Mode Voltage Full 1.2 V Input Resistance (Differential) 25°C 20 kΩ Input Capacitance 25°C 1.5 pF

LOGIC INPUTS (PDWN, SCLK/DTP)

Logic 1 Voltage Full 1.2 3.6 V Logic 0 Voltage Full 0.3 V Input Resistance 25°C 30 kΩ Input Capacitance 25°C 0.5 pF

LOGIC INPUT (CSB)

Logic 1 Voltage Full 1.2 3.6 V Logic 0 Voltage Full 0.3 V Input Resistance 25°C 70 kΩ Input Capacitance 25°C 0.5 pF

LOGIC INPUT (SDIO/ODM)

Logic 1 Voltage Full 1.2 DRVDD + 0.3 V Logic 0 Voltage Full 0 0.3 V Input Resistance 25°C 30 kΩ Input Capacitance 25°C 2 pF

LOGIC OUTPUT (SDIO/ODM)

3

Logic 1 Voltage (IOH = 800 μA) Full 1.79 V Logic 0 Voltage (IOL = 50 μA) Full 0.05 V

DIGITAL OUTPUTS (D + x, D − x), (ANSI-644)

Logic Compliance LVDS Differential Output Voltage (VOD) Full 247 454 mV Output Offset Voltage (VOS) Full 1.125 1.375 V Output Coding (Default) Offset binary

DIGITAL OUTPUTS (D + x, D − x),

(Low Power, Reduced Signal Option) Logic Compliance LVDS Differential Output Voltage (VOD) Full 150 250 mV Output Offset Voltage (VOS) Full 1.10 1.30 V Output Coding (Default) Offset binary

1

See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.

2

This is specified for LVDS and LVPECL only.

3

This is specified for 13 SDIO pins sharing the same connection.

Rev. A | Page 5 of 52

AD9287

SWITCHING SPECIFICATIONS

AVDD = 1.8 V, DRVDD = 1.8 V, 2 V p-p differential input, 1.0 V internal reference, AIN = −0.5 dBFS, unless otherwise noted.

Table 4.

Parameter

CLOCK

1, 2

3

Temp Min Typ Max Unit

Maximum Clock Rate Full 100 MSPS Minimum Clock Rate Full 10 MSPS Clock Pulse Width High (tEH) Full 5 ns Clock Pulse Width Low (tEL) Full 5 ns

OUTPUT PARAMETERS

3

Propagation Delay (tPD) Full 2.0 2.7 3.5 ns Rise Time (tR) (20% to 80%) Full 300 ps Fall Time (tF) (20% to 80%) Full 300 ps FCO Propagation Delay (t DCO Propagation Delay (t

DCO to Data Delay (t

DATA

DCO to FCO Delay (t Data to Data Skew

(t

DATA-MAX

− t

DATA-MIN

)

) Full 2.0 2.7 3.5 ns

FCO

4

FRAME

)

CPD

4

)

4

)

Full

Full (t Full (t

SAMPLE

/16) − 300 (t /16) − 300 (t

+

t

FCO

(t

/16)

SAMPLE

/16) (t

SAMPLE

/16) (t

SAMPLE

ns

/16) + 300 ps

SAMPLE

/16) + 300 ps

SAMPLE

Full ±50 ±150 ps

Wake-Up Time (Standby) 25°C 600 ns Wake-Up Time (Power-Down) 25°C 375 μs Pipeline Latency Full 8 CLK cycles

APERTURE

Aperture Delay (tA) 25°C 500 ps Aperture Uncertainty (Jitter) 25°C <1 ps rms Out-of-Range Recovery Time 25°C 2 CLK cycles

1

See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for definitions and for details on how these tests were completed.

2

Measured on standard FR-4 material.

3

Can be adjusted via the SPI.

4

t

/16 is based on the number of bits multiplied by 2; delays are based on half duty cycles.

SAMPLE

Rev. A | Page 6 of 52

AD9287

TIMING DIAGRAMS

N – 1

AIN

CLK–

CLK+

DCO–

DCO+

FCO–

FCO+

D – x

D + x

t

A

N – 1

N

D4

N – 9

D3

N – 9

t

EL

t

DATA

D2

N – 9

D1

N – 9

D0

N – 9

MSB N – 8

D6

N – 8

D5

N – 8D4N – 8

D3

N – 8D2N – 8

D1

N – 8

5966-040

t

EH

t

CPD

MSB N – 9

t

FRAME

D6

N – 9

D5

N – 9

t

FCO

t

PD

Figure 2. 8-Bit Data Serial Stream, MSB First (Default)

AIN

CLK–

CLK+

DCO–

DCO+

FCO–

FCO+

D – x

D + x

t

A

N

t

FCO

PD

CPD

t

EH

t

FRAME

MSB

D10

N – 9

N – 9D9N – 9D8N – 9D7N – 9D6N – 9D5N – 9D4N – 9D3N – 9

Figure 3. 12-Bit Data Serial Stream, MSB First

t

EL

t

DATA

D2

D1

N – 9

0

D0

N – 9

0

N – 9

0

MSB N – 8

D10

N – 8

5966-039

Rev. A | Page 7 of 52

AD9287

N – 1

AIN

t

A

N

CLK–

CLK+

DCO–

DCO+

FCO–

FCO+

D – x

D + x

t

EH

t

CPD

t

FCO

t

PD

t

FRAME

LSB

N – 9D0N – 9D1N – 9D2N – 9D3N – 9D4N – 9D5N – 9D6N – 9

t

EL

t

DATA

LSB

N – 8D0N – 8D1N – 8D2N – 8D3N – 8D4N – 8

05966-041

Figure 4. 8-Bit Data Serial Stream, LSB First

Rev. A | Page 8 of 52

AD9287

ABSOLUTE MAXIMUM RATINGS

Table 5.

With

Parameter

ELECTRICAL

AVDD AGND −0.3 V to +2.0 V DRVDD DRGND −0.3 V to +2.0 V AGND DRGND −0.3 V to +0.3 V AVDD DRVDD −2.0 V to +2.0 V Digital Outputs

(D + x, D − x, DCO+,

DCO−, FCO+, FCO−) CLK+, CLK− AGND −0.3 V to +3.9 V VIN + x, VIN − x AGND −0.3 V to +2.0 V SDIO/ODM AGND −0.3 V to +2.0 V PDWN, SCLK/DTP, CSB AGND −0.3 V to +3.9 V REFT, REFB, RBIAS AGND −0.3 V to +2.0 V VREF, SENSE AGND −0.3 V to +2.0 V

ENVIRONMENTAL

Operating Temperature

Range (Ambient) Maximum Junction

Temperature Lead Temperature

(Soldering, 10 sec) Storage Temperature

Range (Ambient)

Respect To

DRGND −0.3 V to +2.0 V

−40°C to +85°C

150°C

300°C

−65°C to +150°C

Rating

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

THERMAL IMPEDANCE

Table 6.

Air Flow Velocity (m/sec) θ

0.0 24 °C/W

1.0 21 12.6 1.2 °C/W

2.5 19 °C/W

1

θJA for a 4-layer PCB with solid ground plane (simulated). Exposed pad

soldered to PCB.

1

θ

JA

θ

JB

Unit

JC

ESD CAUTION

Rev. A | Page 9 of 52

AD9287

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

AVDD

VIN – D

VIN + D

AVDD

CLK–

CLK+

AVDD

DRGND

DRVDD

VIN – C

VIN + C

47

48

PIN 1

1

2

3

4

5

6

7

8

9

10

11

12

INDICATOR

14

13

D – D

D + D

REFT

REFB

43

44

AD9287

TOP VIEW

17

18

D – B

D + B

VREF

42

19

D – A

AVDD

45

46

EXPOSED PADDLE, PIN 0 (BOTTO M OF PACKAGE)

16

15

D – C

D + C

SENSE

41

20

D + A

VIN + B

VIN – B

AVDD

RBIAS

37

38

39

40

36

AVDD

35

AVDD

34

VIN – A

33

VIN + A

32

AVDD

31

PDWN

30

CSB

29

SDIO/ODM

28

SCLK/DTP

27

AVDD

26

DRGND

25

DRVDD

222123

24

FCO–

FCO+

DCO–

DCO+

Figure 5. 48-Lead LFCSP Pin Configuration, Top View

Table 7. Pin Function Descriptions

Pin No. Mnemonic Description

0 AGND Analog Ground (Exposed Paddle) 1, 2, 5, 6, 9, 10, 27, 32,

35, 36, 39, 45, 46 11, 26 12, 25 3 4 7

AVDD 1.8 V Analog Supply

DRGND Digital Output Driver Ground DRVDD 1.8 V Digital Output Driver Supply VIN − D ADC D Analog Input Complement VIN + D ADC D Analog Input True

CLK− Input Clock Complement 8 CLK+ Input Clock True 13 14 15 16 17 18

D − D ADC D Digital Output Complement

D + D ADC D Digital Output True

D − C ADC C Digital Output Complement

D + C ADC C Digital Output True

D − B ADC B Digital Output Complement

D + B ADC B Digital Output True 19 D − A ADC A Digital Output Complement 20 D + A ADC A Digital Output True 21 22 23 24

FCO− Frame Clock Output Complement

FCO+ Frame Clock Output True

DCO− Data Clock Output Complement

DCO+ Data Clock Output True 28 SCLK/DTP Serial Clock/Digital Test Pattern 29 30

SDIO/ODM Serial Data IO/Output Driver Mode

CSB Chip Select Bar 31 PDWN Power-Down 33 34

VIN + A ADC A Analog Input True

VIN − A ADC A Analog Input Complement

Rev. A | Page 10 of 52

05966-003

AD9287

Pin No. Mnemonic Description

37 38 40 41 42 43 44 47 48

VIN − B ADC B Analog Input Complement VIN + B ADC B Analog Input True RBIAS External resistor sets the internal ADC core bias current SENSE Reference Mode Selection VREF Voltage Reference Input/Output REFB Differential Reference (Negative) REFT Differential Reference (Positive) VIN + C ADC C Analog Input True VIN − C ADC C Analog Input Complement

Rev. A | Page 11 of 52

AD9287

V



C

S

EQUIVALENT CIRCUITS

DRVDD

IN ± x

Figure 6. Equivalent Analog Input Circuit

LK+

CLK–

10

10k

10

1.25V

V

D– D+

V

05966-030

DRGND

V

5966-005

Figure 9. Equivalent Digital Output Circuit

SCLK/DTP

AND

PDWN

1k

30k

Figure 7. Equivalent Clock Input Circuit

DIO/ODM

350

30k

Figure 8. Equivalent SDIO/ODM Input Circuit

05966-032

05966-033

Figure 10. Equivalent SCLK/DTP and PDWN Input Circuit

RBIAS

05966-035

100

05966-031

Figure 11. Equivalent RBIAS Circuit

Rev. A | Page 12 of 52

AD9287

A

V

DD

70k

CSB

Figure 12. Equivalent CSB Input Circuit

1k

VREF

6k

05966-034

5966-037

Figure 14. Equivalent VREF Circuit

SENSE

1k

05966-036

Figure 13. Equivalent SENSE Circuit

Rev. A | Page 13 of 52

AD9287

TYPICAL PERFORMANCE CHARACTERISTICS

–10

–30

AIN = –0.5dBF S

SNR = 49.21dB

ENOB = 7.88 BI TS

SFDR = 70.89dBc

–10

–30

AIN = –0.5dBF S

SNR = 48.36dB

ENOB = 7.74 BITS

SFDR = 65.17dBc

–50

–70

AMPLITUDE (dBFS)

–90

–110

05

5 1015202530354045

FREQUENCY (MHz )

Figure 15. Single-Tone 32k FFT with f

–10

–30

–50

–70

AMPLITUDE (dBFS)

–90

= 2.4 MHz, f

IN

SAMPLE

AIN = –0.5dBF S

SNR = 49.17dB

ENOB = 7.87 BITS

SFDR = 62.44dBc

0

05966-055

= 100 MSPS

–50

–70

AMPLITUDE (dBFS)

–90

–110

050

5 1015202530354045

Figure 18. Single-Tone 32k FFT with f

–10

–30

–50

–70

AMPLITUDE ( dBFS)

–90

FREQUENCY (MHz )

= 170 MHz, f

IN

= 100 MSPS

SAMPLE

AIN = –0.5dBF S

SNR = 48.07dB

ENOB = 7.69 BI TS

SFDR = 61.37dBc

05966-051

–110

05

5 1015202530354045

FREQUENCY (MHz )

Figure 16. Single-Tone 32k FFT with f

–10

–30

–50

–70

AMPLITUDE ( dBFS)

–90

–110

05

5 1015202530354045

FREQUENCY (MHz )

Figure 17. Single-Tone 32k FFT with f

= 70 MHz, f

IN

= 120 MHz, f

IN

SAMPLE

AIN = –0.5dBF S

SNR = 49.16dB

ENOB = 7.87 BITS

SFDR = 70.32dBc

SAMPLE

0

05966-059

= 100 MSPS

0

05966-060

= 100 MSPS

–110

050

5 1015202530354045

Figure 19. Single-Tone 32k FFT with f

–10

–30

–50

–70

AMPLITUDE ( dBFS)

–90

–110

050

5 1015202530354045

Figure 20. Single-Tone 32k FFT with f

FREQUENCY (MHz)

= 190 MHz, f

IN

FREQUENCY (MHz )

= 225 MHz, f

IN

= 100 MSPS

SAMPLE

AIN = –0.5dBF S

SNR = 48.32dB

ENOB = 7.73 BITS

SFDR = 54.48dBc

= 100 MSPS

SAMPLE

05966-052

05966-053

Rev. A | Page 14 of 52

AD9287

80

75

70

2V p-p, SFDR

65

60

55

SNR/SFDR (dB)

50

2V p-p, SNR

45

40

10 100

20 30 40 50 60 70 80 90

f

(MSPS)

SAMPLE

Figure 21. SNR/SFDR vs. f

80

70

2V p-p, SFDR

60

, fIN = 10.3 MHz, f

SAMPLE

= 100 MSPS

70

60

50

40

30

SNR/SFDR (dB)

20

10

0

–60 0

–50 –40 –30 –20 –10

05966-061

ANALOG INP UT LEVEL (dBFS)

Figure 24. SNR/SFDR vs. Analog Input Level, f

–10

–30

–50

2V p-p, SFDR

60dB REFERENCE

2V p-p, SNR

= 35 MHz, f

IN

AIN1 AND AIN2 = –7dBF S

SAMPLE

SFDR = 72.90dBc

IMD2 = 70.43dBc IMD3 = 71.97dBc

05966-058

= 100 MSPS

50

SNR/SFDR (dB)

2V p-p, SNR

40

30

10 100

20 30 40 50 60 70 80 90

f

(MSPS)

SAMPLE

Figure 22. SNR/SFDR vs. f

80

70

60

50

40

30

SNR/SFDR (dB)

20

10

0

–60 0

–50 –40 –30 –20 –10

ANALOG INP UT LEVEL (dBFS)

, fIN = 35 MHz, f

SAMPLE

2V p-p, SNR

Figure 23. SNR/SFDR vs. Analog Input Level, f

SAMPLE

2V p-p, SFDR

60dB REFERENCE

= 10.3 MHz, f

IN

= 100 MSPS

SAMPLE

–70

AMPLITUDE (dBFS)

–90

–110

05

5 1015202530354045

= 16 MHz, f

f

IN2

= 71 MHz, f

f

IN2

FREQUENCY (MHz )

= 100 MSPS

SAMPLE

FREQUENCY (MHz )

= 100 MSPS

SAMPLE

= 15 MHz and

IN1

= 70 MHz and

IN1

05966-062

Figure 25. Two-Tone 32k FFT with f

AIN1 AND AIN2 = –7dBF S SFDR = 71.14dBc

–10

IMD2 = 69.46d Bc IMD3 = 70.33d Bc

–30

–50

–70

AMPLITUDE ( dBFS)

–90

–110

05

5 1015202530354045

05966-057

Figure 26. Two-Tone 32k FFT with f

0

05966-049

0

05966-050

Rev. A | Page 15 of 52

AD9287

–

80

75

70

65

60

55

50

SNR/SFDR (dB)

45

40

35

30

1

2V p-p, SFDR (dBc)

2V p-p, SNR ( dB)

10 100

ANALOG INPUT FREQUENCY (MHz)

Figure 27. SNR/SFDR vs. Analog Input Frequency, f

SAMPLE

1000

= 100 MSPS

05966-063

0.5

0.4

0.3

0.2

0.1

0

DNL (LSB)

–0.1

–0.2

–0.3

–0.4

–0.5

0

50 100 150 200 250

Figure 30. DNL, f

CODE

= 2.4 MHz, f

IN

SAMPLE

= 100 MSPS

05966-066

80

75

70

2V p-p, SFDR

65

60

55

SNR/SFDR (dB)

50

2V p-p, SNR

45

40

–40

–200 20406080

TEMPERATURE (°C)

Figure 28. SINAD/SFDR vs. Temperature, f

1.0

0.8

0.6

0.4

0.2

0

INL (LSB)

–0.2

–0.4

–0.6

–0.8

–1.0

0 50 100 150 200 250

CODE

Figure 29. INL, f

= 2.4 MHz, f

IN

= 10.3 MHz, f

IN

= 100 MSPS

SAMPLE

= 100 MSPS

SAMPLE

45.0

–45.5

–46.0

–46.5

CMRR (dB)

–47.0

–47.5

–48.0

10 15 20 25 35 4530 40 50

05966-064

Figure 31. CMRR vs. Analog Input Frequency, f

0

–0.2

–0.4

–0.6

–0.8

–1.0

–1.2

–1.4

–1.6

INPUT FULL-SCALE AMPL ITUDE (dB)

–1.8

–2.0

10 100

05966-065

Figure 32. Input Full-Scale Amplitude vs. f

ANALOG INPUT FREQUENCY (MHz)

= 100 MSPS

SAMPLE

20 30 40 50 60 70 80 90

f

(MSPS)

SAMPLE

05966-075

05966-048

Rev. A | Page 16 of 52

AD9287

NPR = 40.1 2dB

–10

–30

–50

–70

AMPLI TUDE (d B)

–90

–110

05

5 1015202530354045

FREQUENCY (MHz )

Figure 33. Noise Power Ratio (NPR), f

NOTCH = 18MHz

NOTCH WIDTH = 3MHz

= 100 MSPS

SAMPLE

0

05966-054

0

–1

–2

–3

–4

–5

–6

–7

FUNDAMENTAL L EVEL (dBF S)

–8

–9

–10

0 50 100 150 200 250 300 350 400 450 500

FREQUENCY (MHz )

Figure 34. Full-Power Bandwidth vs. Frequency, f

–3dB CUTOFF = 295MHz

SAMPLE

05966-077

= 100 MSPS

Rev. A | Page 17 of 52

AD9287

THEORY OF OPERATION

The AD9287 architecture consists of a pipelined ADC divided into three sections: a 4-bit first stage followed by eight 1.5-bit stages and a final 3-bit flash. Each stage provides sufficient overlap to correct for flash errors in the preceding stage. The quantized outputs from each stage are combined into a final 8-bit result in the digital correction logic. The pipelined architecture permits the first stage to operate with a new input sample while the remaining stages operate with preceding samples. Sampling occurs on the rising edge of the clock.

Each stage of the pipeline, excluding the last, consists of a low resolution flash ADC connected to a switched-capacitor DAC and an interstage residue amplifier (for example, a multiplying digital-to-analog converter (MDAC)). The residue amplifier magnifies the difference between the reconstructed DAC output and the flash input for the next stage in the pipeline. One bit of redundancy is used in each stage to facilitate digital correction of flash errors. The last stage simply consists of a flash ADC.

The output staging block aligns the data, corrects errors, and passes the data to the output buffers. The data is then serialized and aligned to the frame and data clocks.

ANALOG INPUT CONSIDERATIONS

The analog input to the AD9287 is a differential switchedcapacitor circuit designed for processing differential input signals. The circuit can support a wide common-mode range while maintaining excellent performance. By using an input common-mode voltage of midsupply, users can minimize signal-dependent errors and achieve optimum performance.

H

C

VIN + x

VIN – x

PAR

C

SAMPLE

SS

C

SAMPLE

C

PAR

H

Figure 35. Switched-Capacitor Input Circuit

The clock signal alternately switches the input circuit between sample mode and hold mode (see

Figure 35). When the input circuit is switched to sample mode, the signal source must be capable of charging the sample capacitors and settling within one-half of a clock cycle. A small resistor in series with each input can help reduce the peak transient current injected from the output stage of the driving source. In addition, low-Q inductors or ferrite beads can be placed on each leg of the input to reduce high differential capacitance at the analog inputs and therefore achieve the maximum bandwidth of the ADC. Such use of low-Q

H

5966-006

Rev. A | Page 18 of 52

inductors or ferrite beads is required when driving the converter front end at high IF frequencies. Either a shunt capacitor or two single-ended capacitors can be placed on the inputs to provide a matching passive network. This ultimately creates a low-pass filter at the input to limit unwanted broadband noise. See the AN-742 Application Note, the AN-827 Application Note, and the Analog Dialogue article “Transformer-Coupled Front-End for Wideband A/D Converters” (Volumne 39, April 2005) for more information on this subject. In general, the precise values depend on the application.

The analog inputs of the AD9287 are not internally dc-biased. Therefore, in ac-coupled applications, the user must provide this bias externally. Setting the device so that V

= AV D D /2 is

CM

recommended for optimum performance, but the device can function over a wider range with reasonable performance, as shown in

Figure 36 and Figure 37.

90

f

= 2.4MHz

IN

f

= 100MSPS

SAMPLE

80

70

60

50

40

SNR/SFDR (dB)

30

20

10

0

0.2 1.6

0.4 0.6 0.8 1. 0 1.2 1.4

ANALOG INP UT COMMON- MODE VOL TAGE (V)

Figure 36. SNR/SFDR vs. Common-Mode Voltage,

= 2.4 MHz, f

f

IN

90

f

= 30MHz

IN

f

= 100MSPS

SAMPLE

80

70

60

50

40

SNR/SFDR (dB)

30

20

10

0

0.2 1.6

0.4 0.6 0.8 1. 0 1.2 1.4

ANALOG INP UT COMMON- MODE VOL TAGE (V)

Figure 37. SNR/SFDR vs. Common-Mode Voltage,

= 30 MHz, f

f

IN

SFDR (dBc)

SNR (dB)

SAMPLE

SFDR (dBc)

SNR (dB)

= 100 MSPS

SAMPLE

= 100 MSPS

05966-067

05966-068

AD9287

A

2

A

V

F

For best dynamic performance, the source impedances driving VIN + x and VIN − x should be matched such that commonmode settling errors are symmetrical. These errors are reduced by the common-mode rejection of the ADC. An internal reference buffer creates the positive and negative reference voltages, REFT and REFB, respectively, that define the span of the ADC core. The output common-mode of the reference buffer is set to midsupply, and the REFT and REFB voltages and span are defined as

REFT = 1/2 (AVDD + VREF) REFB = 1/2 (AVDD − VREF) Span = 2 × (REFT − REFB) = 2 × VREF

It can be seen from these equations that the REFT and REFB voltages are symmetrical about the midsupply voltage and, by definition, the input span is twice the value of the VREF voltage.

Maximum SNR performance is achieved by setting the ADC to the largest span in a differential configuration. In the case of the AD9287, the largest input span available is 2 V p-p.

Differential Input Configurations

There are several ways to drive the AD9287 either actively or passively; however, optimum performance is achieved by driving the analog input differentially. For example, using the

AD8332

differential driver to drive the AD9287 provides excellent performance and a flexible interface to the ADC (see

Figure 41) for baseband applications. This configuration is commonly used for medical ultrasound systems.

For applications where SNR is a key parameter, differential transformer coupling is the recommended input configuration (see

Figure 38 and Figure 39), because the noise performance of most amplifiers is not adequate to achieve the true performance of the AD9287.

Regardless of the configuration, the value of the shunt capacitor, C, is dependent on the input frequency and may need to be reduced or removed.

DT1-1WT

2V p-p

1k

1

C

DIFF

1:1 Z RATIO

49.9

AVD D

0.1F

IS OPTIONAL

C

R

1

C

DIFF

R

C

VIN + x

VIN – x

ADC

AD9287

AGND

05966-008

Figure 38. Differential Transformer-Coupled Configuration

for Baseband Applications

2V p-p

16nH

65

0.1F

1k

DT1-1WT

1:1 Z RATIO

AVD D

499

0.1F

16nH

33

2.2pF 1k

33

VIN + x

ADC

AD9287

VIN – x

Figure 39. Differential Transformer-Coupled Configuration

for IF Applications

Single-Ended Input Configuration

A single-ended input may provide adequate performance in costsensitive applications. In this configuration, SFDR and distortion performance degrade due to the large input common-mode swing. If the application requires a single-ended input configuration, ensure that the source impedances on each input are well matched in order to achieve the best possible performance. A full-scale input of 2 V p-p can be applied to the ADC’s VIN + x pin while the VIN − x pin is terminated.

Figure 40 details a typical single-

ended input configuration.

DD

C

V p-p

49.9

0.1µF

AVD D

1k

25

R

1

C

DIFF

R

C

VIN + x

VIN – x

ADC

AD9287

05966-047

1V p-p

0.1F

0.1

LOP

120nH

0.1F

Figure 41. Differential Input Configuration Using the

22pF

18nF

INH

AD8332

LNA

LMD

LON

274

VIP

VIN

0.1F

1

C

IS OPTIONAL

DIFF

Figure 40. Single-Ended Input Configuration

680nH

187

VOH

VGA

VOL

AD8332 with Two-Pole, 16 MHz Low-Pass Filter

187

68pF

680nH

LPF

10k

33

10k

+

AVDD

10k

33

10k

AVDD

1k

VIN + x

ADC

AD9287

VIN – x

05966-007

05966-009

Rev. A | Page 19 of 52

AD9287

A

C

A

CLOCK INPUT CONSIDERATIONS

For optimum performance, the AD9287 sample clock inputs (CLK+ and CLK−) should be clocked with a differential signal. This signal is typically ac-coupled to the CLK+ and CLK− pins via a transformer or capacitors. These pins are biased internally and require no additional biasing.

Figure 42 shows a preferred method for clocking the AD9287. The low jitter clock source is converted from a single-ended signal to a differential signal using an RF transformer. The back-to-back Schottky diodes across the secondary transformer limit clock excursions into the AD9287 to approximately 0.8 V p-p differential. This helps prevent the large voltage swings of the clock from feeding through to other portions of the AD9287, and it preserves the fast rise and fall times of the signal, which are critical to low jitter performance.

XFMR

0.1µF

®

0.1µF0.1µF

0.1µF

SCHOTTKY

DIODES:

HSM2812

0.1µF

100

0.1µF

240240

0.1µF

100

0.1µF

Figure 45). Although the

CLK+

ADC

AD9287

CLK–

CLK+

ADC

AD9287

CLK–

CLK+

ADC

AD9287

CLK–

05966-024

Rev. A | Page 20 of 52

Mini-Circuits

ADT1-1WT, 1:1Z

CLK+

50

100

Figure 42. Transformer-Coupled Differential Clock

If a low jitter clock is available, another option is to ac-couple a differential PECL signal to the sample clock input pins as shown in

Figure 43. The AD9510/AD9511/AD9512/AD9513/AD9514/

AD9515 family of clock drivers offers excellent jitter performance.

AD9510/AD9511/ AD9512/AD9513/ AD9514/AD9515

CLK+

CLK–

50

1

0.1µF CLK

PECL DRIVER

0.1µF

50

CLK

1

50 RESISTORS ARE OPT IONAL.

Figure 43. Differential PECL Sample Clock

AD9510/AD9511/ AD9512/AD9513/ AD9514/AD9515

CLK+

CLK–

50

1

50 RESISTORS ARE OPT IONAL.

0.1µF CLK

LVDS DRIVER

0.1µF

50

CLK

1

Figure 44. Differential LVDS Sample Clock

In some applications, it is acceptable to drive the sample clock inputs with a single-ended CMOS signal. In such applications, CLK+ should be driven directly from a CMOS gate, and the CLK− pin should be bypassed to ground with a 0.1 F capacitor in parallel with a 39 kΩ resistor (see

05966-025

05966-026

CLK+ input circuit supply is AVDD (1.8 V), this input is designed to withstand input voltages of up to 3.3 V and therefore offers several selections for the drive logic voltage.

D9510/AD9511/

AD9512/AD9513/

0.1µF

LK+

1

50

0.1µF

50 RESISTORS ARE OPTIONAL.

AD9514/AD9515

CLK

CMOS DRIVER

CLK

0.1µF

OPTIONA L

100

39k

0.1µF

CLK+

ADC

AD9287

CLK–

Figure 45. Single-Ended 1.8 V CMOS Sample Clock

D9510/AD9511/

AD9512/AD9513/

CLK+

0.1µF

1

50

0.1µF

1

50 RESISTORS ARE OPTIO NAL.

AD9514/AD9515

CLK

CMOS DRIVER

CLK

OPTION AL

100

0.1µF

CLK+

ADC

AD9287

CLK–

Figure 46. Single-Ended 3.3 V CMOS Sample Clock

Clock Duty Cycle Considerations

Typical high speed ADCs use both clock edges to generate a variety of internal timing signals. As a result, these ADCs may be sensitive to the clock duty cycle. Commonly, a 5% tolerance is required on the clock duty cycle to maintain dynamic performance characteristics. The AD9287 contains a duty cycle stabilizer (DCS) that retimes the nonsampling edge, providing an internal clock signal with a nominal 50% duty cycle. This allows a wide range of clock input duty cycles without affecting the performance of the AD9287. When the DCS is on, noise and distortion performance are nearly flat for a wide range of duty cycles. However, some applications may require the DCS function to be off. If so, keep in mind that the dynamic range performance can be affected when operated in this mode. See the

Memory Map section for more details on

using this feature.

Jitter in the rising edge of the input is an important concern and is not reduced by the internal stabilization circuit. The duty cycle control loop does not function for clock rates of less than 20 MHz nominal. The loop has a time constant associated with it that must be considered in applications where the clock rate can change dynamically. This requires a wait time of 1.5 µs to 5 µs after a dynamic clock frequency increase (or decrease) before the DCS loop is relocked to the input signal. During the period that the loop is not locked, the DCS loop is bypassed, and the internal device timing is dependent on the duty cycle of the input clock signal. In such applications, it may be appropriate to disable the duty cycle stabilizer. In all other applications, enabling the DCS circuit is recommended to maximize ac performance.

05966-027

05966-028

AD9287

Clock Jitter Considerations

High speed, high resolution ADCs are sensitive to the quality of the clock input. The degradation in SNR at a given input frequency (f due only to aperture jitter (t

SNR degradation = 20 × log 10(1/2 × π × f

) can be calculated by

J

A

× tJ)

A

In this equation, the rms aperture jitter represents the root mean square of all jitter sources, including the clock input, analog input signal, and ADC aperture jitter. IF undersampling applications are particularly sensitive to jitter (see

Figure 47).

The clock input should be treated as an analog signal in cases where aperture jitter may affect the dynamic range of the AD9287. Power supplies for clock drivers should be separated from the ADC output driver supplies to avoid modulating the clock signal with digital noise. Low jitter, crystal-controlled oscillators are the best clock sources. If the clock is generated from another type of source (by gating, dividing, or another method), it should be retimed by the original clock during the last step.

Refer to the AN-501 Application Note and to the AN-756 Application Note for more in-depth information about jitter performance as it relates to ADCs (visit

130

RMS CLOCK JI TTER REQ UIREMENT

120

110

100

90

80

SNR (dB)

70

10 BITS

60

8 BITS

50

40

30

1 10 10 0 1000

ANALOG INPUT FREQUENCY (MHz)

Figure 47. Ideal SNR vs. Input Frequency and Jitter

0.125ps

0.25ps

www.analog.com).

0.5ps

1.0ps

2.0ps

16 BITS

14 BITS

12 BITS

05966-038

)

Power Dissipation and Power-Down Mode

As shown in Figure 48, the power dissipated by the AD9287 is proportional to its sample rate. The digital power dissipation does not vary significantly because it is determined primarily by the DRVDD supply and bias current of the LVDS output drivers.

300

AVDD CURRENT

250

200

150

CURRENT (mA)

100

50

0

Figure 48. Supply Current vs. f

20 40 60 80 100

01

ENCODE (MSPS)

SAMPLE

TOTAL POWER

DRVDD CURRENT

for fIN = 10.3 MHz, f

SAMPLE

600

550

500

450

POWER (mW)

400

350

300

20

= 100 MSPS

05966-069

Rev. A | Page 21 of 52

AD9287

By asserting the PDWN pin high, the AD9287 is placed into power-down mode. In this state, the ADC typically dissipates 3 mW. During power-down, the LVDS output drivers are placed into a high impedance state. If any of the SPI features are changed before the power-down feature is enabled, the chip continues to function after PDWN is pulled low without requiring a reset. The AD9287 returns to normal operating mode when the PDWN pin is pulled low. This pin is both 1.8 V and 3.3 V tolerant.

In power-down mode, low power dissipation is achieved by shutting down the reference, reference buffer, PLL, and biasing networks. The decoupling capacitors on REFT and REFB are discharged when entering power-down mode and must be recharged when returning to normal operation. As a result, the wake-up time is related to the time spent in the power-down mode: shorter cycles result in proportionally shorter wake-up times. With the recommended 0.1 µF and 2.2 µF decoupling capacitors on REFT and REFB, approximately 1 sec is required to discharge the reference buffer decoupling capacitors fully and approximately 375 µs is required to restore full operation.

There are several other power-down options available when using the SPI. The user can individually power down each channel or put the entire device into standby mode. The latter option allows the user to keep the internal PLL powered when fast wake-up times (~600 ns) are required. See the Map

section for more details on using these features.

Memory

Digital Outputs and Timing

The AD9287 differential outputs conform to the ANSI-644 LVDS standard on default power-up. This can be changed to a low power, reduced signal option (similar to the IEEE 1596.3 standard) via the SDIO/ODM pin or SPI. The LVDS standard can reduce the overall power dissipation of the device by approximately 17 mW. See the

SDIO/ODM Pin section or Tab le 1 6 in the Memory Map section for more information. The LVDS driver current is derived on-chip and sets the output current at each output equal to a nominal 3.5 mA. A 100 Ω differential termination resistor placed at the LVDS receiver inputs results in a nominal 350 mV swing at the receiver.

The AD9287 LVDS outputs facilitate interfacing with LVDS receivers in custom ASICs and FPGAs for superior switching performance in noisy environments. Single point-to-point net topologies are recommended with a 100 Ω termination resistor

placed as close to the receiver as possible. If there is no far-end receiver termination or there is poor differential trace routing, timing errors may result. To avoid such timing errors, it is recommended that each trace length is less than 24 inches and that the differential output traces are close together and at equal lengths. An example of the FCO and data stream with proper trace length and position is shown in

CH1 500mV/DIV = F CO CH2 500mV/DIV = DATA CH3 500mV/DIV = DCO

Figure 49. LVDS Output Timing Example in ANSI-644 Mode (Default)

Figure 49.

2.5ns/DIV

05966-056

An example of the LVDS output using the ANSI-644 standard (default) data eye and a time interval error (TIE) jitter histogram with trace lengths less than 24 inches on standard FR-4 material is shown in

Figure 50. Figure 51 shows an example of trace lengths exceeding 24 inches on standard FR-4 material. Notice that the TIE jitter histogram reflects the decrease of the data eye opening as the edge deviates from the ideal position. It is the user’s responsibility to determine if the waveforms meet the timing budget of the design when the trace lengths exceed 24 inches. Additional SPI options allow the user to further increase the internal termination (increasing the current) of all four outputs in order to drive longer trace lengths (see

Figure 52). Even though this produces sharper rise and fall times on the data edges and is less prone to bit errors, the power dissipation of the DRVDD supply increases when this option is used. In addition, notice in is improved compared with that shown in

Figure 52 that the histogram

Figure 51. See the

Memory Map section for more details.

Rev. A | Page 22 of 52

AD9287

500

EYE: ALL BITS

ULS: 10000/15600

400

200

EYE: ALL BITS

ULS: 9599/15599

0

EYE DIAGRAM VOLTAG E (V)

–500

–1.0ns –0.5ns 0ns 0.5ns 1. 0ns

100

50

TIE JITTER HISTO GRAM (Hits)

0

–100ps 0ps 100ps

5966-043

Figure 50. Data Eye for LVDS Outputs in ANSI-644 Mode with Trace Lengths Less than 24 Inches on Standard FR-4, External 100 Ω Far Termination Only

EYE: ALL BITS

200

0

EYE DIAG RAM VOLTAG E (V)

–200

–1.0ns –0.5ns 0ns 0.5ns 1.0n s

100

50

TIE JITTER HISTO GRAM (Hits)

ULS: 9600/15600

0

–200

EYE DIAGRA M VOLT AGE (V)

–400

–1.0ns –0.5ns 0ns 0.5ns 1.0n s

100

50

TIE JIT TER HIST OGRAM (Hit s)

0

–150ps –100p s –50ps 0p s 50ps 100ps 150ps

05966-042

Figure 52. Data Eye for LVDS Outputs in ANSI-644 Mode with 100 Ω Internal

Termination on and Trace Lengths Greater than 24 Inches on Standard FR-4,

External 100 Ω Far Termination Only

The format of the output data is offset binary by default. An example of the output coding format can be found in

Tabl e 8. To change the output data format to twos complement, see the Memory Map section.

Table 8. Digital Output Coding

(VIN + x) − (VIN − x), Input Span = 2 V p-p (V)

Code

255 +1.00 1111 1111 128 0.00 1000 0000 127 −0.007813 0111 1111 0 −1.00 0000 0000

Digital Output Offset Binary (D7 ... D0)

Data from each ADC is serialized and provided on a separate channel. The data rate for each serial stream is equal to 8 bits times the sample clock rate, with a maximum of 800 Mbps (8 bits × 100 MSPS = 800 Mbps). The lowest typical conversion rate is 10 MSPS. However, if lower sample rates are required for a specific application, the PLL can be set up via the SPI to allow encode rates as low as 5 MSPS. See the

Memory Map section for

details on enabling this feature.

0

–150ps –100p s –50ps 0p s 50ps 100ps 150ps

05966-044

Figure 51. Data Eye for LVDS Outputs in ANSI-644 Mode with Trace Lengths

Greater than 24 Inches on Standard FR-4, External 100 Ω Far Termination

Only

Rev. A | Page 23 of 52

AD9287

Two output clocks are provided to assist in capturing data from the AD9287. The DCO is used to clock the output data and is equal to four times the sample clock (CLK) rate. Data is clocked out of the AD9287 and must be captured on the rising and

Table 9. Flexible Output Test Modes

Output Test Mode Bit Sequence

Pattern Name Digital Output Word 1 Digital Output Word 2

0000 Off (default) N/A N/A N/A 0001 Midscale short

1000 0000 (8-bit) 10 0000 0000 (10-bit) 1000 0000 0000 (12-bit) 10 0000 0000 0000 (14-bit)

0010 +Full-scale short

1111 1111 (8-bit) 11 1111 1111 (10-bit) 1111 1111 1111 (12-bit) 11 1111 1111 1111 (14-bit)

0011 −Full-scale short

0000 0000 (8-bit) 00 0000 0000 (10-bit) 0000 0000 0000 (12-bit) 00 0000 0000 0000 (14-bit)

0100 Checkerboard

1010 1010 (8-bit) 10 1010 1010 (10-bit) 1010 1010 1010 (12-bit)

10 1010 1010 1010 (14-bit) 0101 PN sequence long 0110 PN sequence short 0111 One-/zero-word toggle

1

N/A N/A Yes

1111 1111 (8-bit)

11 1111 1111 (10-bit)

1111 1111 1111 (12-bit)

11 1111 1111 1111 (14-bit) 1000 User input Register 0x19 to Register 0x1A Register 0x1B to Register 0x1C No 1001 1-/0-bit toggle

1010 1010 (8-bit)

10 1010 1010 (10-bit)

1010 1010 1010 (12-bit)

10 1010 1010 1010 (14-bit) 1010 1× sync

0000 1111 (8-bit)

00 0001 1111 (10-bit)

0000 0011 1111 (12-bit)

00 0000 0111 1111 (14-bit) 1011 One bit high

1000 0000 (8-bit)

10 0000 0000 (10-bit)

1000 0000 0000 (12-bit)

10 0000 0000 0000 (14-bit) 1100 Mixed frequency

1010 0011 (8-bit)

10 0110 0011 (10-bit)

1010 0011 0011 (12-bit)

10 1000 0110 0111 (14-bit)

1

All test mode options except PN sequence short and PN sequence long can support 8- to 14-bit word lengths in order to verify data capture to the receiver.

falling edges of the DCO that supports double data rate (DDR) capturing. The FCO is used to signal the start of a new output byte and is equal to the sample clock rate. See the timing diagram shown in

Figure 2 for more information.

Subject to Data Format Select

Same Yes

0101 0101 (8-bit)

No 01 0101 0101 (10-bit) 0101 0101 0101 (12-bit) 01 0101 0101 0101 (14-bit)

0000 0000 (8-bit)

No 00 0000 0000 (10-bit) 0000 0000 0000 (12-bit) 00 0000 0000 0000 (14-bit)

N/A No

Rev. A | Page 24 of 52

AD9287

When the SPI is used, the DCO phase can be adjusted in 60° increments relative to the data edge. This enables the user to refine system timing margins if required. The default DCO+ and DCO− timing, as shown in

Figure 2, is 90° relative to the output data edge.

A 10-, 12-, or 14-bit serial stream can also be initiated from the SPI. This allows the user to implement and test compatibility with higher resolution systems. However, when using the 12-bit option, the data stream stuffs four 0s at the end of the 12-bit serial data (see

Figure 3).

When the SPI is used, all of the data outputs can also be inverted from their nominal state. This is not to be confused with inverting the serial stream to an LSB-first mode. In default mode, as shown in

Figure 2, the MSB is first in the data output serial stream. However, this can be inverted so that the LSB is first in the data output serial stream (see

Figure 4).

There are 12 digital output test pattern options available that can be initiated through the SPI. This is a useful feature when validating receiver capture and timing. Refer to

Tabl e 9 for the output bit sequencing options available. Some test patterns have two serial sequential words and can be alternated in various ways, depending on the test pattern chosen. It should be noted that some patterns do not adhere to the data format select option. In addition, custom user-defined test patterns can be assigned in the 0x19, 0x1A, 0x1B, and 0x1C register addresses. All test mode options except PN sequence short and PN sequence long can support 8- to 14-bit word lengths in order to verify data capture to the receiver.

The PN sequence short pattern produces a pseudorandom bit

9

sequence that repeats itself every 2

− 1 or 511 bits. A description of the PN sequence and how it is generated can be found in Section 5.1 of the ITU-T 0.150 (05/96) standard. The only difference is that the starting value must be a specific value instead of all 1s (see

Tabl e 10 for the initial values).

Table 10. PN Sequence

Initial

Sequence

PN Sequence Short 0x0df 0xbf, ox93, 0x53 PN Sequence Long 0x029b80 0xf5, 0x91, 0xfd

Value

First Three Output Samples (MSB First)

Consult the Memory Map section for information on how to change these additional digital output timing features through the SPI.

SDIO/ODM Pin

The SDIO/ODM pin is for use in applications that do not require SPI mode operation. This pin can enable a low power, reduced signal option (similar to the IEEE 1596.3 reduced range link output standard) if it and the CSB pin are tied to AVDD during device power-up. This option should only be used when the digital output trace lengths are less than 2 inches to the LVDS receiver. When this option is used, the FCO, DCO, and outputs function normally, but the LVDS signal swing of all channels is reduced from 350 mV p-p to 200 mV p-p, allowing the user to further reduce the power on the DRVDD supply.

For applications where this pin is not used, it should be tied low. In this case, the device pin can be left open, and the 30 kΩ internal pull-down resistor pulls this pin low. This pin is only 1.8 V tolerant. If applications require this pin to be driven from a 3.3 V logic level, insert a 1 kΩ resistor in series with this pin to limit the current.

Table 11. Output Driver Mode Pin Settings

Resulting

Selected ODM ODM Voltage

Normal operation

ODM AVDD Low power,

10 kΩ to AGND ANSI-644

Output Standard

(default)

reduced signal option

Resulting FCO and DCO

ANSI-644 (default)

Low power, reduced signal option

The PN sequence long pattern produces a pseudorandom bit

23

sequence that repeats itself ever y 2

− 1 or 8,388,607 bits. A description of the PN sequence and how it is generated can be found in Section 5.6 of the ITU-T 0.150 (05/96) standard. The only differences are that the starting value must be a specific value instead of all 1s (see

Tabl e 10 for the initial values) and the

AD9287 inverts the bit stream with relation to the ITU standard.

Rev. A | Page 25 of 52

AD9287

SCLK/DTP Pin

The SCLK/DTP pin is for use in applications that do not require SPI mode operation. This pin can enable a single digital test pattern if it and the CSB pin are held high during device powerup. When SCLK/DTP is tied to AVDD, the ADC channel outputs shift out the following pattern: 1000 0000. The FCO and DCO function normally while all channels shift out the repeatable test pattern. This pattern allows the user to perform timing alignment adjustments among the FCO, DCO, and output data. For normal operation, this pin should be tied to AGND through a 10 kΩ resistor. This pin is both 1.8 V and 3.3 V tolerant.

Table 12. Digital Test Pattern Pin Settings

Resulting

Selected DTP DTP Voltage

Normal operation

DTP AVDD 1000 0000 Normal operation

10 kΩ to AGND Normal

D + x and D − x

operation

Resulting FCO and DCO

Normal operation

Additional and custom test patterns can also be observed when commanded from the SPI port. Consult the

Memory Map

section for information about the options available.

CSB Pin

The CSB pin should be tied to AVDD for applications that do not require SPI mode operation. By tying CSB high, all SCLK and SDIO information is ignored. This pin is both 1.8 V and

3.3 V tolerant.

RBIAS Pin

To set the internal core bias current of the ADC, place a resistor (nominally equal to 10.0 kΩ) to ground at the RBIAS pin. The resistor current is derived on-chip and sets the AVDD current of the ADC to a nominal 260 mA at 100 MSPS. Therefore, it is imperative that at least a 1% tolerance on this resistor be used to achieve consistent performance.

Voltage Reference

A stable, accurate 0.5 V voltage reference is built into the AD9287. This is gained up internally by a factor of 2, setting V

to 1.0 V, which results in a full-scale differential input span

REF

of 2 V p-p. The V

is set internally by default; however, the

REF

VREF pin can be driven externally with a 1.0 V reference to improve accuracy.

When applying the decoupling capacitors to the VREF, REFT, and REFB pins, use ceramic low ESR capacitors. These capacitors should be close to the ADC pins and on the same layer of the PCB as the AD9287. The recommended capacitor values and configurations for the AD9287 reference pin are shown in Figure 53.

Table 13. Reference Settings

Resulting Differential

Selected Mode SENSE Voltage Resulting VREF (V)

External reference

Internal, 2 V p-p FSR

AVDD N/A 2 × external

AGND to 0.2 V 1.0 2.0

Span (V p-p)

reference

Rev. A | Page 26 of 52

AD9287

Internal Reference Operation

A comparator within the AD9287 detects the potential at the SENSE pin and configures the reference. If SENSE is grounded, the reference amplifier switch is connected to the internal resistor divider (see

Figure 53), setting VREF to 1 V.

External Reference Operation

The use of an external reference may be necessary to enhance the gain accuracy of the ADC or to improve thermal drift characteristics.

Figure 56 shows the typical drift characteristics

of the internal reference in 1 V mode.

The REFT and REFB pins establish the input span of the ADC core from the reference configuration. The analog input fullscale range of the ADC equals twice the voltage of the reference pin for either an internal or an external reference configuration.

If the reference of the AD9287 is used to drive multiple converters to improve gain matching, the loading of the reference by the other converters must be considered.

Figure 55

depicts how the internal reference voltage is affected by loading.

VIN + x

VIN – x

VREF

1µF 0. 1µF

SENSE

VIN + x

VIN – x

EXTERNAL

REFERENCE

1

1µF

0.1µF

SENSE

ADC

CORE

SELECT

LOGIC

Figure 53. Internal Reference Configuration

ADC

CORE

VREF

1

AVD D

SELECT

LOGIC

0.5V

REFT

0.1µF

0.1µF 2.2µF

REFB

0.1µF

REFT

0.1µF

0.1µF 2.2µF

REFB

0.1µF

+

When the SENSE pin is tied to AVDD, the internal reference is disabled, allowing the use of an external reference. The external reference is loaded with an equivalent 6 kΩ load. An internal reference buffer generates the positive and negative full-scale references, REFT and REFB, for the ADC core. Therefore, the external reference must be limited to a nominal 1.0 V.

5

0

–5

–10

ERROR (%)

–15

REF

V

–20

–25

–30

01.00.5 2. 01.5 3.02.5 3.5

0.02

ERROR (%)

REF

V

–0.02

–0.04

–0.06

–0.08

–0.10

–0.12

–0.14

–0.16

–0.18

0

–40 806040200–20

05966-010

Figure 56. V

CURRENT LOAD (mA)

Figure 55. V

TEMPERATURE ( °C)

Error vs. Temperature

REF

Error vs. Load

REF

05966-083

05966-084

1

OPTIONAL.

Figure 54. External Reference Operation

05966-089

Rev. A | Page 27 of 52

AD9287

SERIAL PORT INTERFACE (SPI)

The AD9287 serial port interface allows the user to configure the converter for specific functions or operations through a structured register space provided in the ADC. This may provide the user with additional flexibility and customization depending on the application. Addresses are accessed via the serial port and can be written to or read from via the port. Memory is organized into bytes that can be further divided into fields, as documented in the

Memory Map section. Detailed operational information can be found in the Analog Devices, Inc., AN-877 Application Note, Interfacing to High Speed ADCs via SPI.

There are three pins that define the SPI: SCLK, SDIO, and CSB

Tabl e 14 ). The SCLK pin is used to synchronize the read

(see and write data presented to the ADC. The SDIO pin is a dualpurpose pin that allows data to be sent to and read from the internal ADC memory map registers. The CSB pin is an active low control that enables or disables the read and write cycles.

Table 14. Serial Port Pins

Pin Function

SCLK

SDIO

CSB

Serial Clock. The serial shift clock input. SCLK is used to synchronize serial interface reads and writes.

Serial Data Input/Output. A dual-purpose pin. The typical role for this pin is as an input or output, depending on the instruction sent and the relative position in the timing frame.

Chip Select Bar (Active Low). This control gates the read and write cycles.

The falling edge of the CSB in conjunction with the rising edge of the SCLK determines the start of the framing sequence. During an instruction phase, a 16-bit instruction is transmitted followed by one or more data bytes, which is determined by Bit Field W0 and Bit Field W1. An example of the serial timing and its definitions can be found in

Figure 58 and Tab l e 15 . During normal operation, CSB is used to signal to the device that SPI commands are to be received and processed. When CSB is brought low, the device processes SCLK and SDIO to obtain instructions. Normally, CSB remains low until the communication cycle is complete. However, if connected to a slow device, CSB can be brought high between bytes, allowing older microcontrollers enough time to transfer data into shift registers. CSB can be stalled when transferring one, two, or three bytes of data. When W0 and W1 are set to 11, the device enters streaming mode and continues to process data, either reading or writing, until the CSB is taken high to end the communication cycle. This allows complete memory transfers without requiring additional instructions. Regardless of the mode, if CSB is taken high in the middle of a byte transfer, the SPI state machine is reset and the device waits for a new instruction.

In addition to the operation modes, the SPI port configuration influences how the AD9287 operates. For applications that do not require a control port, the CSB line can be tied and held high. This places the remainder of the SPI pins into their secondary modes, as defined in the

SDIO/ODM Pin and SCLK/DTP Pin section. CSB can also be tied low to enable 2-wire mode. When CSB is tied low, SCLK and SDIO are the only pins required for communication. Although the device is synchronized during power-up, the user should ensure that the serial port remains synchronized with the CSB line when using this mode. When operating in 2-wire mode, it is recommended to use a 1-, 2-, or 3-byte transfer exclusively. Without an active CSB line, streaming mode can be entered but not exited.

In addition to word length, the instruction phase determines if the serial frame is a read or write operation, allowing the serial port to be used to both program the chip and read the contents of the on-chip memory. If the instruction is a readback operation, performing a readback causes the SDIO pin to change from an input to an output at the appropriate point in the serial frame.

Data can be sent in MSB- or LSB-first mode. MSB-first mode is the default at power-up and can be changed by adjusting the configuration register. For more information about this and other features, see the AN-877 Application Note, Inter facing to High Speed ADCs via SPI.

HARDWARE INTERFACE

The pins described in Ta b l e 14 compose the physical interface between the user’s programming device and the serial port of the AD9287. The SCLK and CSB pins function as inputs when using the SPI. The SDIO pin is bidirectional, functioning as an input during write phases and as an output during readback.

If multiple SDIO pins share a common connection, care should be taken to ensure that proper V same load for each AD9287, SDIO pins that can be connected together and the resulting V level. This interface is flexible enough to be controlled by either serial PROMS or PIC mirocontrollers, providing the user with an alternative method, other than a full SPI controller, to program the ADC (see the AN-812 Application Note).

levels are met. Assuming the

OH

Figure 57 shows the number of

OH

Rev. A | Page 28 of 52

AD9287

1.800

1.795

1.790

1.785

1.780

1.775

1.770

1.765

1.760

OH

1.755

V

1.750

1.745

1.740

1.735

1.730

1.725

1.720

1.715 0302010 40 50 60 70 80 90 100

NUMBER OF SDIO PINS CONNECTE D TOGETHER

Figure 57. SDIO Pin Loading

05966-090

If the user chooses not to use the SPI, these dual-function pins serve their secondary functions when the CSB is strapped to AVDD during device power-up. See the

Theory of Operation section for details on which pin-strappable functions are supported on the SPI pins.

For users who wish to operate the ADC without using the SPI, remove any connections from the CSB, SCLK/DTP, and SDIO/ ODM pins. By disconnecting these pins from the control bus, the ADC can function in its most basic operation. Each of these pins has an internal termination and will float to its respective level.

t

HI

t

LO

CSB

SCLK

SDIO

DON’T CARE

t

DS

t

S

R/W W1 W 0 A12 A11 A10 A9 A8 A7

t

DH

Figure 58. Serial Timing Details

Table 15. Serial Timing Definitions

Parameter Timing (Minimum, ns) Description

t

DS

t

DH

t

CLK

t

S

t

H

t

HI

t

LO

t

EN_SDIO

5 Setup time between the data and the rising edge of SCLK 2 Hold time between the data and the rising edge of SCLK 40 Period of the clock 5 Setup time between CSB and SCLK 2 Hold time between CSB and SCLK 16 Minimum period that SCLK should be in a logic high state 16 Minimum period that SCLK should be in a logic low state 10

Minimum time for the SDIO pin to switch from an input to an output relative to the SCLK falling edge (not shown in

t

DIS_SDIO

10

Minimum time for the SDIO pin to switch from an output to an input relative to the SCLK rising edge (not shown in

CLK

Figure 58)

D5 D4 D3 D2 D1 D0

t

H

DON’T CARE

DON’T CAREDON’T CARE

05966-012

Rev. A | Page 29 of 52

AD9287

MEMORY MAP

READING THE MEMORY MAP TABLE

Each row in the memory map table has eight address locations. The memory map is divided into three sections: the chip configuration register map (Address 0x00 to Address 0x02), the device index and transfer register map (Address 0x05 and Address 0xFF), and the ADC functions register map (Address 0x08 to Address 0x22).

The leftmost column of the memory map indicates the register address number, and the default value is shown in the second rightmost column. The (MSB) Bit 7 column is the start of the default hexadecimal value given. For example, Address 0x09, the clock register, has a default value of 0x01, meaning that Bit 7 = 0, Bit 6 = 0, Bit 5 = 0, Bit 4 = 0, Bit 3 = 0, Bit 2 = 0, Bit 1 = 0, and Bit 0 = 1, or 0000 0001 in binary. This setting is the default for the duty cycle stabilizer in the on condition. By writing a 0 to Bit 6 of this address followed by a 0x01 in Register 0xFF (transfer bit), the duty cycle stabilizer turns off. It is important to follow each writing sequence with a transfer bit to update the SPI registers. For more information on this and other functions, consult the AN-877 Application Note, Interfacing to High Speed ADCs via SPI.

RESERVED LOCATIONS

Undefined memory locations should not be written to except when writing the default values suggested in this data sheet. Addresses that have values marked as 0 should be considered reserved and have a 0 written into their registers during power-up.

DEFAULT VALUES

When the AD9287 comes out of a reset, critical registers are preloaded with default values. These values are indicated in Tabl e 16 , where an X refers to an undefined feature.

LOGIC LEVELS

An explanation of various registers follows: “Bit is set” is synonymous with “bit is set to Logic 1” or “writing Logic 1 for the bit.” Similarly, “clear a bit” is synonymous with “bit is set to Logic 0” or “writing Logic 0 for the bit.”

Rev. A | Page 30 of 52

AD9287

Table 16. Memory Map Register

Default Addr. (Hex)

Chip Configuration Registers

00 chip_port_config 0 LSB first

01 chip_id 8-bit Chip ID Bits [7:0]

02 chip_grade X Child ID [6:4]

Device Index and Transfer Registers

05 device_index_A X X Clock

FF device_update X X X X X X X SW

ADC Functions

08 modes X X X X X Internal power-down mode

09 clock X X X X X X X Duty

0D test_io User test mode

Register Name

(MSB) Bit 7

00 = off (default) 01 = on, single alternate 10 = on, single once 11 = on, alternate once

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

1 = on 0 = off (default)

(identify device variants of Chip ID) 011 = 100 MSPS

Soft reset 1 = on 0 = off (default)

Channel DCO 1 = on 0 = off (default)

Reset PN long gen 1 = on 0 = off (default)

1 1 Soft

(AD9287 = 0x05), (default)

Clock Channel FCO 1 = on 0 = off (default)

Reset PN short gen 1 = on 0 = off (default)

(LSB) Bit 0

LSB first reset 1 = on 0 = off (default)

X X X X Read

Data Channel D 1 = on (default) 0 = off

Output test mode—see

Data Channel C 1 = on (default) 0 = off

000 = chip run (default) 001 = full power-down 010 = standby 011 = reset

1 = on

0 = off

(default)

Data

Channel

B

1 = on

(default)

0 = off

Table 9 in the

0 0x18 The nibbles

Data Channel A 1 = on (default) 0 = off

transfer 1 = on 0 = off (default)

cycle stabilizer 1 = on (default) 0 = off

Digital Outputs and Timing section

0000 = off (default) 0001 = midscale short 0010 = +FS short 0011 = −FS short 0100 = checkerboard output 0101 = PN 23 sequence 0110 = PN 9 0111 = one-/zero-word toggle 1000 = user input 1001 = 1-/0-bit toggle 1010 = 1× sync 1011 = one bit high 1100 = mixed bit frequency (format determined by output_mode)

Value (Hex)

0x05 Default is unique

only

0x0F Bits are set to

0x00 Synchronously

0x00 Determines

0x01 Turns the

0x00 When set, the

Default Notes/ Comments

should be mirrored so that LSB- or MSB-first mode is set correctly regardless of shift mode.

chip ID, different for each device. This is a readonly register.

Child ID used to differentiate graded devices.

determine which on-chip device receives the next write command.

transfers data from the master shift register to the slave.

various generic modes of chip operation.

internal duty cycle stabilizer on and off.

test data is placed on the output pins in place of normal data.

Rev. A | Page 31 of 52

AD9287

Default Addr. (Hex)

14 output_mode X 0 = LVDS

15 output_adjust X X Output driver

16 output_phase X X X X 0011 = output clock phase adjust

19 user_patt1_lsb B7 B6 B5 B4 B3 B2 B1 B0 0x00 User-defined

1A user_patt1_msb B15 B14 B13 B12 B11 B10 B9 B8 0x00 User-defined

1B user_patt2_lsb B7 B6 B5 B4 B3 B2 B1 B0 0x00 User-defined

1C user_patt2_msb B15 B14 B13 B12 B11 B10 B9 B8 0x00 User-defined

21 serial_control LSB first

22 serial_ch_stat X X X X X X Channel

Register Name

(MSB) Bit 7

1 = on 0 = off (default)

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

ANSI-644 (default) 1 = LVDS low power, (IEEE

1596.3 similar)

X X X <10

X X X Output

X X X X 0x00 Determines termination 00 = none (default) 01 = 200 Ω 10 = 100 Ω 11 = 100 Ω

(0000 through 1010)

(Default: 180° relative to data edge)

0000 = 0° relative to data edge

0001 = 60° relative to data edge

0010 = 120° relative to data edge

0011 = 180° relative to data edge

0100 = 240° relative to data edge

0101 = 300° relative to data edge

0110 = 360° relative to data edge

0111 = 420° relative to data edge

1000 = 480° relative to data edge

1001 = 540° relative to data edge

1010 = 600° relative to data edge

1011 to 1111 = 660° relative to data edge

MSPS,

low

encode

rate

mode

1 = on

0 = off

(default)

invert 1 = on 0 = off (default)

000 = 8 bits (default, normal bit stream) 001 = 8 bits 010 = 10 bits 011 = 12 bits 100 = 14 bits

00 = offset binary (default) 01 = twos complement

output reset 1 = on 0 = off (default)

(LSB) Bit 0

Channel powerdown 1 = on 0 = off (default)

Value (Hex)

0x00 Configures the

0x03 On devices that

0x00 Serial stream

0x00 Used to power

Default Notes/ Comments

outputs and the format of the data.

LVDS or other output properties. Primarily functions to set the LVDS span and common-mode levels in place of an external resistor.

utilize global clock divide, determines which phase of the divider output is used to supply the output clock. Internal latching is unaffected.

pattern, 1 LSB.

pattern, 1 MSB.

pattern, 2 LSB.

pattern, 2 MSB.

control. Default causes MSB first and the native bit stream (global).

down individual sections of a converter (local).

Rev. A | Page 32 of 52

AD9287

Power and Ground Recommendations Exposed Paddle Thermal Heat Slug Recommendations

When connecting power to the AD9287, it is recommended that two separate 1.8 V supplies be used: one for analog (AVDD) and one for digital (DRVDD). If only one supply is available, it should be routed to the AVDD first and then tapped off and isolated with a ferrite bead or a filter choke preceded by decoupling capacitors for the DRVDD. The user can employ several different decoupling capacitors to cover both high and low frequencies. These should be located close to the point of entry at the PC board level and close to the parts, with minimal trace lengths.

A single PC board ground plane should be sufficient when using the AD9287. With proper decoupling and smart partitioning of the PC board’s analog, digital, and clock sections, optimum performance can be easily achieved.

It is required that the exposed paddle on the underside of the ADC is connected to analog ground (AGND) to achieve the best electrical and thermal performance of the AD9287. An exposed continuous copper plane on the PCB should mate to the AD9287 exposed paddle, Pin 0. The copper plane should have several vias to achieve the lowest possible resistive thermal path for heat dissipation to flow through the bottom of the PCB. These vias should be solder-filled or plugged.

To maximize the coverage and adhesion between the ADC and PCB, partition the continuous copper plane by overlaying a silkscreen on the PCB into several uniform sections. This provides several tie points between the ADC and PCB during the reflow process, whereas using one continuous plane with no partitions only guarantees one tie point. See

Figure 59 for a PCB layout example. For detailed information on packaging and the PCB layout of chip scale packages, see the AN-772 Application Note,

A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP), at

SILKSCREEN PARTITIO N

PIN 1 INDICATOR

www.analog.com.

05966-013

Figure 59. Typical PCB Layout

Rev. A | Page 33 of 52

AD9287

EVALUATION BOARD

The AD9287 evaluation board provides all of the support circuitry required to operate the ADC in its various modes and configurations. The converter can be driven differentially using a transformer (default) or an

AD8332 driver. The ADC can also be driven in a single-ended fashion. Separate power pins are provided to isolate the DUT from the drive circuitry of the

AD8332. Each input configuration can be selected by changing the connection of various jumpers (see

Figure 62 to Figure 66). Figure 60 shows the typical bench characterization setup used to evaluate the ac performance of the AD9287. It is critical that the signal sources used for the analog input and clock have very low phase noise (<1 ps rms jitter) to realize the optimum performance of the converter. Proper filtering of the analog input signal to remove harmonics and lower the integrated or broadband noise at the input is also necessary to achieve the specified noise performance.

Figure 62 to Figure 70 for the complete schematics and

See layout diagrams demonstrating the routing and grounding techniques that should be applied at the system level.

POWER SUPPLIES

This evaluation board has a wall-mountable switching power supply that provides a 6 V, 2 A maximum output. Connect the supply to the rated 100 V ac to 240 V ac wall outlet at 47 Hz to 63 Hz. The other end of the supply is a 2.1 mm inner diameter jack that connects to the PCB at P503. Once on the PC board, the 6 V supply is fused and conditioned before connecting to three low dropout linear regulators that supply the proper bias to each of the various sections on the board.

When operating the evaluation board in a nondefault condition, L504 to L507 can be removed to disconnect the switching power supply. This enables the user to bias each section of the board individually. Use P501 to connect a different supply for

WALL OU TL ET 100V TO 240V AC 47Hz TO 63Hz

6V DC

SWITCHING

POWER SUPPLY

ROHDE & SCHWARZ,

SMHU, 2V p-p SIGNAL SYNTHESIZER

ROHDE & SCHWARZ,

SMHU,

2V p-p SIGNAL SYNTHESIZER

2A MAX

BAND-PASS

FILTER

XFMR INPUT

CLK

5.0V

–+

GND

1.8V –+–+

GND

AVD D_5V

AVDD_DUT

AD9287

EVALUATION BOARD

Figure 60. Evaluation Board Connection

1.8V

GND

DRVDD_DUT

–+

CH A TO CH D

each section. At least one 1.8 V supply is needed for AVDD_DUT and DRVDD_DUT; however, it is recommended that separate supplies be used for analog and digital signals and that each supply have a current capability of 1 A. To operate the evaluation board using the VGA option, a separate 5.0 V analog supply (AVDD_5 V) is needed. To operate the evaluation board using the SPI and alternate clock options, a separate 3.3 V analog supply (AVDD_3.3 V) is needed in addition to the other supplies.

INPUT SIGNALS

When connecting the clock and analog sources to the evaluation board, use clean signal generators with low phase noise, such as Rohde & Schwarz SMHU or HP8644 signal generators or the equivalent, as well as a 1 m, shielded, RG-58, 50 Ω coaxial cable. Enter the desired frequency and amplitude from the ADC specifications tables. Typically, most Analog Devices evaluation boards can accept approximately 2.8 V p-p or 13 dBm sine wave input for the clock. When connecting the analog input source, it is recommended to use a multipole, narrow-band, band-pass filter with 50 Ω terminations. Good choices of such band-pass filters are available from TTE, Allen Avionics, and K&L Microwave, Inc. The filter should be connected directly to the evaluation board if possible.

OUTPUT SIGNALS

The default setup uses the HSC-ADC-FPGA-4/HSC-ADC-

FPGA-8

digital output data and convert it to parallel CMOS. These two channels interface directly with the Analog Devices standard dual-channel FIFO data capture board ( Two of the four channels can then be evaluated at the same time. For more information on the channel settings and optional settings of these boards, visit www.analog.com/FIFO.

3.3V

GND

AVDD_3.3V

8-BIT

SERIAL

LVDS

SPI SPISPI SPI

high speed deserialization board to deserialize the

HSC-ADC-EVALB-DC).

3.3V

–+

GND

HSC-ADC-FPGA-4/

HSC-ADC-FPGA-8

DESERIALIZ ATION

1.5V

–+

3.3V_D

HIGH SPEED

BOARD

PARALLEL

CMOS

GND

2 CH

8-BIT

1.5V_FPG A

HSC-ADC-EVALB-DC

3.3V

–+

GND

FIFO DATA

CAPTURE

BOARD

CONNECTION

VCC

USB

PC

RUNNING

ADC

ANALYZER

AND SPI

USER

SOFTWARE

5966-014

Rev. A | Page 34 of 52

AD9287

DEFAULT OPERATION AND JUMPER SELECTION SETTINGS

The following is a list of the default and optional settings or modes allowed on the AD9287 Rev. A evaluation board.

• POWER: Connect the switching power supply that is

provided with the evaluation kit between a rated 100 V ac to 240 V ac wall outlet at 47 Hz to 63 Hz and P503.

• AIN: The evaluation board is set up for a transformer-

coupled analog input with an optimum 50 Ω impedance match of 190 MHz of bandwidth (see bandwidth response, the differential capacitor across the analog inputs can be changed or removed. The common mode of the analog inputs is developed from the center tap of the transformer or AVDD_DUT/2.

0

–2

–4

–6

–8

–10

AMPLITUDE ( dBFS)

–12

–14

–16

50 100 150 200 250 300 350 400 450 500

0

Figure 61. Evaluation Board Full-Power Bandwidth

–3dB CUTOFF = 190MHz

FREQUENCY (MHz)

• VREF: VREF is set to 1.0 V by tying the SENSE pin to ground,

R237. This causes the ADC to operate in 2.0 V p-p full-scale range. A separate external reference option using the ADR510 or ADR520 is also included on the evaluation board. Populate R231 and R235 and remove C214. Proper use of the VREF options is noted in the

Volt a ge R e fe r e nc e section.

• RBIAS: RBIAS has a default setting of 10 kΩ (R201) to

ground and is used to set the ADC core bias current.

• CLOCK: The default clock input circuitry is derived from a

simple transformer-coupled circuit using a high bandwidth 1:1 impedance ratio transformer (T201) that adds a very low amount of jitter to the clock path. The clock input is 50 Ω terminated and ac-coupled to handle single-ended sine wave types of inputs. The transformer converts the single-ended input to a differential signal that is clipped before entering the ADC clock inputs.

Figure 61). For more

05966-088

A differential LVPECL clock can also be used to clock the ADC input using the AD9515 (U202). Populate R225 and R227 with 0 Ω resistors and remove R217 and R218 to disconnect the default clock path inputs. In addition, populate C207 and C208 with a 0.1 F capacitor and remove C210 and C211 to disconnect the default clock path outputs. The AD9515 has many pin-strappable options that are set to a default mode of operation. Consult the AD9515 data sheet for more information about these and other options.

In addition, an on-board oscillator is available on the OSC201 and can act as the primary clock source. The setup is quick and involves installing R212 with a 0 Ω resistor and setting the enable jumper (J205) to the on position. If the user wishes to employ a different oscillator, two oscillator footprint options are available (OSC201) to check the ADC performance.

• PDWN: To enable the power-down feature, short J201 to

AVDD on the PDWN pin.

• SCLK/DTP: To enable the digital test patterns on the digital

outputs of the ADC, use J204. If J204 is tied to AVDD during device power-up, Test Pattern 1000 0000 is enabled. See the SCLK/DTP Pin section for details.

• SDIO/ODM: To enable the low power, reduced signal option

(similar to the IEEE 1595.3 reduced range link LVDS output standard), use J203. If J203 is tied to AVDD during device power-up, it enables the LVDS outputs in a low power, reduced signal option from the default ANSI-644 standard. This option changes the signal swing from 350 mV p-p to 200 mV p-p, reducing the power of the DRVDD supply. See the

SDIO/ODM Pin section for more details.

• CSB: To enable processing of the SPI information on the SDIO

and SCLK pins, tie J202 low in the always enable mode. To ignore the SDIO and SCLK information, tie J202 to AVDD.

• Non-SPI Mode: For users who wish to operate the DUT

without using SPI, remove Jumpers J202, J203, and J204. This disconnects the CSB, SCLK/DTP, and SDIO/ODM pins from the control bus, allowing the DUT to operate in its simplest mode. Each of these pins has internal termination and will float to its respective level.

• D + x, D − x: If an alternative data capture method to the setup

described in

Figure 60 is used, optional receiver terminations, R206 to R211, can be installed next to the high speed backplane connector.

Rev. A | Page 35 of 52

AD9287

ALTERNATIVE ANALOG INPUT DRIVE CONFIGURATION

The following is a brief description of the alternative analog input drive configuration using the option is in use, some components may need to be populated, in which case all the necessary components are listed in more details on the and its optional pin settings, consult the

To configure the analog input to drive the VGA instead of the default transformer option, the following components need to be removed and/or changed.

• Remove R102, R115, R128, R141, R161, R162, R163, R164,

T101, T102, T103, and T104 in the default analog input path.

AD8332 dual VGA, including how it works

AD8332 dual VGA. If this drive

Tabl e 17 . For

AD8332 data sheet.

• Populate R101, R114, R127, and R140 with 0 Ω resistors in

the analog input path.

• Populate R105, R113, R118, R124, R131, R137, R151, and

R160 with 0 Ω resistors in the analog input path to connect the

AD8332.

• Populate R152, R153, R154, R155, R156, R157, R158, R159,

C103, C105, C110, C112, C117, C119, C124, and C126 with 10 kΩ resistors to provide an input common-mode level to the ADC analog inputs.

• Remove R305, R306, R313, R314, R405, R406, R412, and

R424 to configure the

In this configuration, L301 to L308 and L401 to L408 are populated with 0 Ω resistors to allow signal connection and use of a filter if additional requirements are necessary.

AD8332.

Rev. A | Page 36 of 52

AD9287

R105 DNP

CH_A

VGA INPUT CO NNECTION

CHANNEL A P101

INH1

AIN

R101 DNP

R102

64.9

P102 DNP

AIN

AVDD_DUT

R103

0

R104

0

FB101

10

C102

0.1µF

R111

1k

C101

0.1µF

E101

CM1

CH_A

R112

1k

CM1

1

2

3

T101

R113

DNP

6

5

4

C107

0.1µF

CM1

R107 DNP

C106 DNP

R106 DNP

FB102

10

R161 499

FB103

10

R108

33

C103

DNP

R110

33

AVDD_DUT

C104

2.2pF

C105 DNP

AVDD_DUT

R152 DNP

R109 1k

R156 DNP

VIN_A

AVDD_DUT

CH_B

CM2

CH_B

R126

1k

R132 DNP

6

5

4

C128

0.1µF

CM2

T102

1

2

3

R124

FB108

FB109

CM4

R118 DNP

DNP

10

R163 499

10

R145 DNP

C127 DNP

6

5

4

C114

0.1µF

R134

33

C117

DNP

R136

33

R144 DNP

CM2

R120

DNP

C113 DNP

FB111

10

R164 499

FB112

10

R119 DNP

AVDD_DUT

C118

2.2pF

C119 DNP

AVDD_DUT

R146

33

C124

DNP

R147

33

FB105

10

R162 499

FB106

10

R154 DNP

R135 1k

R158 DNP

R121

33

C110

DNP

R122

33

VIN_C

AVDD_DUT

C125

2.2pF

C126 DNP

AVDD_DUT

R155 DNP

R148 1k

R159 DNP

C111

2.2pF

C112 DNP

R153 DNP

R123 1k

R157 DNP

AVDD_DUT

VIN_D

VIN_B

05966-015

VGA INPUT CO NNECTION

CHANNEL C P105

INH3

AIN

VGA INPUT CO NNECTION

CHANNEL D P107

AIN

DNP: DO NOT PO PULATE

VGA INP UT CONN ECTIO N

CHANNEL B P103

INH2

AIN

P106 DNP

R130

0

AIN

R127 DNP

FB107

R129

0

AVDD_DUT

10

R138

1k

R128

64.9

INH4

R140 DNP

R141

64.9

P108 DNP

AIN

R142

AVDD_DUT

R114 DNP

R115

64.9

C116

0.1µF

E103

0

P104 DNP

AIN

C115

0.1µF

R139

R117

AVDD_DUT

CH_C

CM3

CH_C

CM3

1k

FB110

10

R143

0

1

2

3

R149

1k

R131 DNP

T103

R137

DNP

C122

0.1µF

C123

0.1µF

E104

FB104

10

R116

0

6

5

4

C121

0.1µF

CM4

R150

1k

CH_D

R125

1k

CM3

R133

CM4

C108

0.1µF

C109

0.1µF

E102

DNP

C120 DNP

T104

1

2

3

R160

DNP

R151 DNP

Figure 62. Evaluation Board Schematic, DUT Analog Inputs

Rev. A | Page 37 of 52

AD9287

R206

DNP

R207

FCO

DCO

50

D9

D10

GNDCD9

GNDCD10

C10

P202

DIGITAL OUTPUTS

T U D _ E S

V

N

5 .

E

0

S

=

V

F E R V

T

P

C

N

E

D L E S

4

F

P

3

E

N

2

R

D

R

V

T I

U C R

I C

E C N E R E F E R

T U D _ F E R V

1

P

3 2

N

R

D



k

9

T

9

2

9

U

2

.

D

R

4 _ D

+

D

V

V A

0 2

/ 0 1

L

V

5

1

A

F

N

E

O

R

I T

T

P

X

O

E

C

R

N /

D A

M

3

I

0

R

2

T

U

REFERENCE

DECOUPLI NG

C204

0.1µF

C9

40

60

59

FCO

DCO

)

L

3

A

3

N

2

R

R /

E

2

T

3

X

2

E

R +

=

1 (

F

V

E

5 .

R

0

V

= F

E R V

P

N

D

5

6

P

3

N

2

D

R

AVDD_DUT

4

2

P

1

3

F

N

2

µ

D

C

1

R

P N D

0



3

k

2

0

R

1

2

F

1

µ

2

1 .

C

0

– V



8

k

2

0

2

7

R

4

1



0

k

2

0

R

1

C203

0.1µF

C202

2.2µF

DNP

49

GNDCD8

39

3 1 2 C

C201

CW

R209

R208

DNP

CHB

CHA

48

D8

D7

GNDCD7

C8

C7

38

57

58

CHB

CHA

V 1

= F

E R V

F E R V

L A N R E T X

7

E

3



2

0

G

R

N I

S U

N E H

3

P

3

W

N

2

D

4

R

1 2

F

C

µ

E

1 .

V

0

O M E R

T U D _ D D V A

VIN_B

VIN_B AVDD_DUT

VSENSE_DUT VREF_DUT

AVDD_DUT AVDD_DUT

VIN_C

0.1µF

47

GNDCD6

37

DNP

37

38 39

40 41 42

43 44 45

46 47

48

U201

R211

DNP

R210

DNP

CHD

CHC

46

45

44

43

42

41

20

19

D6

D5

D4

D3

D2

D1

B10

GNDCD1

GNDCD2

GNDCD3

GNDCD4

GNDCD5

C6

C5

C4

C3

C2

32

33

34

35

36

54

55

56

CHD

CHC

52

53

0

R257

DNP

R256

AVDD_3.3V

0

R247

R245

DNP

R244

R246

I P S

E L

AVDD_3.3V

E L B A N E

N D

W P

3

2

J201

J202

1

R202

100k

100k - DNP

R267

100k - DNP R266

T

T U D _ D D V A

36

AVDD

1

T U D _ D D V A

U

D

_

D

A

D

_

D

N

V

I

A

V

A

33

34

32

35

AVDD

VIN – A

VIN + A

VIN – B VIN + B

AVDD

RBIAS

SENSE

VREF

REFB

REFT

AVDD AVDD

VIN + C VIN – C

VIN + D

VIN – D

AVDD

5

4

3

2

T

D

_

U

N

D

I

_

V

D

V

A

AVDD_3.3V

B A N E

S Y A

W L

ODM ENABLE

A

3

4

0

2

J

1

CSB_DUT

SDIO_ODM

28

29

31

27

CSB

PDWN

SCLK/DTP

SDIO/ODM

AD9287 LFCSP

CLK+

CLK–

AVDD

8

730

6

9

10

T

K L

U

CLK

C

D

_

D

V

A

GNDAB9

GNDAB10

C1

C10

31

10

30

51

0

R259

R261

DNP

R258

R260

S6

S7

AVDD_3.3V

0

R249

R251

DNP

R248

R250

S2

S1

AVDD_3.3V

E L B A N E

P T D

3

2

P T D _ K

10k

L

R205

C S

100k

R204

100k

R203

T

U

D _

D

V

D

N

V

R

A

G

D

25

26

AVDD

DRVDD

DRGND

DCO+ DCO–

FCO+ FCO–

D + A D – A D + B

D – B D + C D – C

D + D D – D

DRVDD

DRGND

AVDD

11

12

T

D

U

N

D

G

_

D

V

A

R D

18

B9

B8

B7

GNDAB7

GNDAB8

A7

A8

A9

9

8

29

28

27

0

R263

R265

DNP

R262

R264

S9

S8

AVDD_3.3V

0

R253

R255

DNP

R252

R254

S4S0S5

S3

AVDD_3.3V

DCO

24

DCO

23

FCO

22

FCO

21

CHA

20

CHA

19

CHB

18

CHB

17

CHC

16

CHC

15

CHD

14

13

AVDD_3.3V

CHD

SCLK_CHA

17

16

B6

B5

GNDAB5

GNDAB6

A5

A6

6

7

25

26

SCLK_CHB

S10

AVDD_3.3V

OPTI ONAL CLO CK DRIVE CIRC UIT

ENABLE

R214

10k

C224

0.1µF

OSCILLATOR

OPTI ONAL CLO CK

CSB1_CHA

SDI_CHA

15

14

B4

B3

GNDAB3

GNDAB4

A3

A4

4

5

24

SDI_CHB

CSB3_CHB

CLK

DNP

C207

0.1µF

AVDD_3.3V

2



2

k

2

R

0 .

4

R221

10k

AVDD_3.3V

DNP

R220

DNP

R219

J205

DISABLE

R215

10k

1

2

5

OE

OE'

OSC201

VCC'

VCC

14

12

10

AVDD_3.3V

GNDAB2

13

GND'

OUT'

C208

33

31

1

32

U202

OPT_CLK

ENCODE

R242

7813

SDO_CHA

CSB2_CHA

12

11

B2

B1

GNDAB1

A1

A2

HEADER 6469 169-1

1

2233

21

22

LVPECL OUTPUT

T C E

R205 TO R211

N N O C

O

SDO_CHB

N

CSB4_CHB

= C

N

CLK

E202

1

DNP

0.1µF

100

23

22

OUT0

GND_PAD

GND

VS

RSET

CLK

3

2

6



2

9 .

2

9

R

4

5 2



2

0

R

OUT0B

CLKB

P N D

AD9515

P N D

R241

R240

SIGNAL = AV DD_3.3V;4,17, 20,21,24,26,29, 30

5

C209

243

18

19

S0

OUT1

OUT1B

S1

S2 S3

S4 S5 S6

S7 S8

SIGNAL = DNC;27,28

S9 S10 VREF

SYNCB

9



3

k

2

0

R

1

8

P

3 2

N

R

D

7

P

2



N

2

0

D

R

0.1µF

R243

9 8

7 6

C223

0.1µF

C222

0.1µF

C221

0.1µF

TERMINATIONS

OPTIONAL OUTPUT

C220

0.1µF

C219

0.1µF

C218

0.1µF

AVDD_3.3V

C217

0.1µF

E203

)

LVDS OUTPUT

DNP

100

25 16 15

14 13

12 11 10

T L

1

U A F E D

( T

U O

DNP

C215

0.1µF

E N

I S

P I

L

CLK

C

C210

0.1µF

S0S1S2S3S4S5S6S7S8S9S10

3

CR201

HSMS2812

1

E201

3 2



2

0

R

43

T201

7 1



2

0

R

OPT_CLK

C205

GNDOUT

0.1µF

VFAC3H-L

R213

P201

49.9k

P203

ENC

DNP

R2120DNP

INPUT

CLOCK CI RCUIT

5

2

C216

R216

05966-016

CLK

C211

0.1µF

E

1

T A L U P

2

O P

T O N

O D

: P N D

4 2



2

0

R

F

6

µ

0

1

2

.

C

0

6

1

8 1



2

0

R

0.1µF

0

Figure 63. Evaluation Board Schematic, DUT, VREF, Clock Inputs, and Digital Output Interface

Rev. A | Page 38 of 52

AD9287

POPULATE L301 TO L308 WITH 0 RESISTORS OR DESIGN YOUR OWN FI LTER.

POWER DOW N ENABLE

C311

0.1µF

C312

0.1µF

R312 10k

(0V TO 1V = DISABLE POW ER)

R313 10k

DNP

AVDD_5V

VPSV

LMD1

5

0

L307

0

C307

0.1µF

2023182219

NC

LMD2

CH_C

C302

DNP

C304

DNP

R304

DNP

R306 374

R309 187

VOL2

INH2

7

VOH2

VPS2

17

COMM

LON2

8

R302 DNP

L304

0

L308

0

C308

0.1µF

1000pF

R310 187

RCLMP

GAIN

MODE

VCM2

VIN2 VIP2

COM2

LOP2

CH_C

EXTERNAL VARIABL E GAIN DRIVE

VARIABLE GAIN CIRCUIT (0V TO 1.0V DC)

C309

AVDD_5V

C310

0.1µF

16

VG

15 14 13 12 11 10

9

C313

0.1µF

C314

0.1µF

R320 39k

R311 10k DNP

CW

AVDD_5V

VG

R319 10k

R314 10k DNP

VG

1

JP301

2

GND

RCLAMP P IN

HILO PIN = LO = ±50mV

HILO PIN = H = ±75mV

24

LON1

2

C301

DNP

C303 DNP

R303 DNP

R305

374

R308

187

VOH1

COMM

VPS1

364

INH1

CH_D

L3020L303

L306 0

C306

0.1µF

21

VOL1

AD8332

CH_D

R301

DNP

L301 0

L305 0

C305

0.1µF

R307 187

U301

25

ENBV

26

ENBL

27

HILO

28

VCM1

29

VIN1

30

VIP1

31

COM1

32

LOP1

1

HILO PIN

HI GAIN RANGE = 2.25V TO 5.0V

LO GAI N RANGE = 0V TO 1.0V

OPTIONAL VGA DRIVE CI RCUIT FOR CHANNEL C AND CHANNEL D

R315 10k

DNP: DO NOT POPULATE

C315 10µF

C316

0.1µF

R316 274

C317

0.018µF

C320

0.1µF

AVDD_5V

C318

22pF

L309 120nH

C319

0.1µF

INH4 INH3

C321

0.1µF

AVDD_5V

C323 22pF

L310 120nH

C324

0.1µF

R317 274

C322

0.018µF

C325

0.1µF

Figure 64. Evaluation Board Schematic, Optional DUT Analog Input Drive and SPI Interface Circuit

C326 10µF

R318 10k

MODE PIN

POSITIVE GAIN SLOPE = 0V TO 1.0V

NEGATIVE GAIN SLOPE = 2.25V TO 5.0V

05966-017

Rev. A | Page 39 of 52

AD9287

R433

1k

AVDD_3.3V

05966-018

AVDD_DUT

SDIO_ODM

REMOVE WHEN USING

OR PROGRAMMING PIC (U402)

SDO_CHA

0

R427

SDI_CHA

0

R420

SCLK_CHA

0

R428

CSB1_CHA

C408

C407

C406

C405

0

R426

R421

0, DNP

VSS

VDD

U402

AVDD_5V

J402

C427

0.1µF

AVDD_3.3V

R413

10k

DNP

C412

0.1µF

C411

R410

187

0.1µF

1000pF

R406

374

0.1µF

R405

0.1µF

17 18

R409

187

19

20

AVDD_5V

21 22

R408

187

23

374

24

R407

187

R423

0, DNP

R422

0, DNP

5

687

GP2

GP0

GP1

PIC12F629

GP4

GP5

MCLR/

GP3

R419

261

4

312

4.75k

R418

3

4

S401

1

2

RESET/REPROGRAM

HILO P IN = H = ± 75mV HILO PIN = LO = ±50mV RCLAMP PI N

R424

10k

DNP

AVDD_5V

VG

15

16

GAIN

VCM2

MODE

RCLMP

COMM

VOH2

VOL2

NC

VPSV VOL1

VOH1

COMM

VCM1

ENBL

ENBV

10k

26

251427

R412

10k

HILO

2813291230

DNP

U401

R411

AVDD_5V

SPI CIRCUITRY F ROM FIFO

+3.3V = NORMAL O PERATION = AVDD_3.3V

+5V = PROGRAMMING = AVDD_5V

YOUR OWN FIL TER. 0 RESISTO RS OR DESIGN POPULATE L401 TO L408 WITH

CH_A

L404

R402

DNP

CH_A

CH_B

C402

L403

L402

DNP

C401

DNP

L401

R401

0

L408

DNP

C404

R404

0

L407

L406

0

DNP

R403

DNP

C403

L405

0

(0V TO 1V = DISABLE POWER) POWER DOWN ENABL E

Figure 65. Evaluation Board Schematic, Optional DUT Analog Input Drive and SPI Interface Circuit (Continued)

AVDD_DUT

1k

R431

1k

R432

NC7WZ07

CR401

C423

11

VIP2

VIN2

COM2

AD8332

VIN1

VIP1

COM1

31

C409

C429

0.1µF

5

6

Y1

Y2A2

VCC

GND

A1

1234

OPTIONAL

0.1µF

10

32

0.1µF

U403

R425

10k

E401

C424

0.1µF

9

LOP2

LON2

8

VPS2

7

INH2

6

LMD2

5

LMD1

4

INH1 VPS1 LON1

LOP1

C416

3 2

1

R415

C410

0.1µF

LO GAIN RANGE = 0V TO 1.0V HI GAIN RANGE = 2. 25V TO 5.0V HILO PIN

OPTIONAL VGA DRIVE CIRCUIT FOR CHANNEL A AND CHANNEL B

SCLK_DTP

CSB_DUT

AVDD_DUT

C428

0.1µF

5

6

Y1

Y2A2

VCC

NC7WZ16

GND

A11

PICVCC

GP1

GP0 MCLR/GP3

R417

10k

C426

10µF

C425

0.1µF

274 R416

AVDD_5V

C417

0.1µF

AVDD_5V

274

C414

0.1µF

10µF

C413

R414

10k

U404

2

34

R429

10k

R430

10k

J401

2

1

4

3

5

7 9

C415

GP1

GP0

6 8 10

NEGATIVE GAIN SLOPE = 2.25V TO 5.0V POSITIVE GAIN SLOPE = 0V TO 1.0V MODE PIN

0.018µF

C420

C421

C418

0.018µF

PICVCC

MCLR/GP3

PIC PROG RAMMI NG HEADER

L410

120nH

22pF

L409

120nH

22pF

DNP: DO NOT POP ULATE

C422

0.1µF

INH2 INH1

C419

0.1µF

Rev. A | Page 40 of 52

AD9287

D5023ASHOT_RECT

C531

AVDD_DUT

+1.8V

0.1µF

C530

0.1µF

C529

0.1µF

C528

0.1µF

C527

0.1µF

C526

0.1µF

H3H1

H4

H2

L506

U502

3.3V_AVDD

10µH

C533

1µF

L507

10µH

4

23

OUTPUT1

OUTPUT4

GND

1

ADP33339AKC-3.3

INPUT

1µF

C532

PWR_IN

4

2

OUTPUT1

OUTPUT4

ADP33339AKC-5

INPUT

U504

3

C534

PWR_IN

MOUNTING HOLES

CONNECTED TO GROUND

0.1µF

C517

0.1µF

C525

0.1µF

C524

AVDD_3.3V

+3.3V

C516

DRVDD_DUT

+1.8V

C523

0.1µF

C522

0.1µF

C521

0.1µF

C520

0.1µF

C519

0.1µF

C518

0.1µF

DECOUPLING CAPACITORS

CR501

R501

PWR_IN

DO-214AB

261

AVDD_5V

+5.0V

05966-019

C535

1µF

GND

1

1µF

21

34

FER501

F501

POWER SUPPLY INPUT

6V, 2V MAXIMUM

SMDC110F

1

P503

CHOKE_COIL

D501

S2A_RECT2ADO-214AA

C501

10µF

+

2

3

AVDD_5V

C503

C502

10µF

L503

10µH

DUT_AVDD

5V_AVDD

1234567

P1P2P3P4P5P6P7

P501

OPTIONAL POWER INPUT

AVDD_DUT

L502

3.3V_AVDD

C505

C504

10µH

DUT_DRVDD

0.1µF

AVDD_3.3V

0.1µF

10µF

8

P8

C509

0.1µF

C508

10µF

L508

10µH

L501

DRVDD_DUT

0.1µF

C507

10µF

C506

10µH

DUT_AVDD

L505

10µH

C515

1µF

4

OUTPUT1

OUTPUT4

GND

1

ADP33339AKC-1.8

INPUT

U501

32

1µF

C514

PWR_IN

DUT_DRVDD 5V_AVDD

10µH

L504

U503

C513

1µF

4

OUTPUT4

OUTPUT1

GND

1

ADP33339AKC-1.8

INPUT

32

1µF

C512

DNP: DO NOT POPULATE

PWR_IN

Figure 66. Evaluation Board Schematic, Power Supply Inputs

Rev. A | Page 41 of 52

AD9287

05966-020

Figure 67. Evaluation Board Layout, Primary Side

Rev. A | Page 42 of 52

AD9287

05966-021

Figure 68. Evaluation Board Layout, Ground Plane

Rev. A | Page 43 of 52

AD9287

Figure 69. Evaluation Board Layout, Power Plane

Rev. A | Page 44 of 52

05966-022

AD9287

Figure 70. Evaluation Board Layout, Secondary Side (Mirrored Image)

Rev. A | Page 45 of 52

05966-023

AD9287

Table 17. Evaluation Board Bill of Materials (BOM)

Item Qty. Reference Designator Device Package Value Manufacturer

1 1 AD9287LFCSP_REVA PCB PCB PCB 2 75

3 4

4 4

5 1 C202 Capacitor 603

6 2 C309, C411 Capacitor 402

7 4

8 4

9 1 C501 Capacitor 1206

10 9

11 8

12 4

13 1 CR201 Diode SOT-23

14 2 CR401, CR501 LED 603

15 1 D502 Diode DO-214AB 3 A, 30 V, SMC

16 1 D501 Diode DO-214AA 2 A, 50 V, SMC

C101, C102, C107, C108, C109, C114, C115, C116, C121, C122, C123, C128, C201, C203, C204, C205, C206, C210, C211, C212, C213, C216, C217, C218, C219, C220, C221, C222, C223, C224, C310, C311, C312, C313, C314, C316, C319, C320, C321, C324, C325, C409, C410, C412, C414, C416, C417, C419, C422, C423, C424, C425, C427, C428, C429, C503, C505, C507, C509, C516, C517, C518, C519, C520, C521, C522, C523, C524, C525, C526, C527, C528, C529, C530, C531

C104, C111, C118, C125

C315, C326, C413, C426

C317, C322, C415, C420

C318, C323, C418, C421

C214, C512, C513, C514, C515, C532, C533, C534, C535

C305, C306, C307, C308, C405, C406, C407, C408

C502, C504, C506, C508

Capacitor 402

Capacitor 805

Capacitor 402

Capacitor 603

Capacitor 805

Capacitor 603

1

Manufacturer’s Part Number

0.1 μF, ceramic, X5R, 10 V, 10% tol

2.2 pF, ceramic, COG, 0.25 pF tol, 50 V

10 μF, 6.3 V ±10% ceramic, X5R

2.2 μF, ceramic, X5R, 6.3 V, 10% tol

1000 pF, ceramic, X7R, 25 V, 10% tol

0.018 μF, ceramic, X7R, 16 V, 10% tol

22 pF, ceramic, NPO, 5% tol, 50 V

10 μF, tantalum, 16 V, 20% tol

1 μF, ceramic, X5R,

6.3 V, 10% tol

0.1 μF, ceramic, X7R, 50 V, 10% tol

10 μF, ceramic, X5R, 6.3 V, 20% tol

30 V, 20 mA, dual Schottky

Green, 4 V, 5 m candela

Murata GRM155R71C104KA88D

Murata GRM1555C1H2R2GZ01B

Murata GRM219R60J106KE19D

Murata GRM188C70J225KE20D

Murata GRM155R71H102KA01D

AVX 0402YC183KAT2A

Murata GRM1555C1H220JZ01D

Rohm TCA1C106M8R

Murata GRM188R61C105KA93D

Murata GRM21BR71H104KA01L

Murata GRM188R60J106M

Agilent Technologies

Panasonic LNJ314G8TRA

Micro Commercial Co.

HSMS2812-TRIG

SK33-TP

S2A-TP

Rev. A | Page 46 of 52

AD9287

Manufacturer’s

Item Qty. Reference Designator Device Package Value Manufacturer

17 1 F501 Fuse 1210

18 1 FER501 Choke coil 2020

19 12

20 1 JP301 Connector 2-pin

21 2 J205, J402 Connector 3-pin

22 1 J201 to J204 Connector 12-pin

23 1 J401 Connector 10-pin

24 8

25 4 L309, L310, L409, L410 Inductor 402

26 16

27 1 OSC201 Oscillator SMT

28 5

29 1 P202 Connector Header

30 1 P503 Connector 0.1", PCMT

31 15

32 14

33 4

34 4

FB101, FB102, FB103, FB104, FB105, FB106, FB107, FB108, FB109, FB110, FB111, FB112

L501, L502, L503, L504, L505, L506, L507, L508

L301, L302, L303, L304, L305, L306, L307, L308, L401, L402, L403, L404, L405, L406, L407, L408

P101, P103, P105, P107, P201

R201, R205, R214, R215, R221, R239, R312, R315, R318, R411, R414, R417, R425, R429, R430

R103, R117, R129, R142, R216, R217, R218, R223, R224, R237, R420, R426, R427, R428

R102, R115, R128, R141

R104, R116, R130, R143

Ferrite bead 603

Ferrite bead 1210

Resistor 805 0 Ω, 1/8 W, 5% tol

Connector SMA

Resistor 402

Resistor 603

6.0 V, 2.2 A tripcurrent resettable fuse

10 μH, 5 A, 50 V, 190 Ω @ 100 MHz

10 Ω, test freq 100 MHz, 25% tol, 500 mA

100 mil header jumper, 2-pin

100 mil header jumper, 3-pin

100 mil header male, 4 × 3 triple row straight

100 mil header, male, 2 × 5 double row straight

10 μH, bead core

3.2 × 2.5 × 1.6 SMD, 2 A

120 nH, test freq 100 MHz, 5% tol, 150 mA

Clock oscillator,

100.00 MHz, 3.3 V Side-mount SMA

for 0.063" board thickness

1469169-1, right angle 2-pair, 25 mm, header assembly

SC1153, power supply connector

10 kΩ, 1/16 W, 5% tol

0 Ω, 1/16 W, 5% tol

64.9 Ω, 1/16 W, 1% tol

0 Ω, 1/10 W, 5% tol

Tyco/Raychem NANOSMDC110F-2

Murata DLW5BSN191SQ2L

Murata BLM18BA100SN1B

Samtec TSW-102-07-G-S

Samtec TSW-103-07-G-S

Samtec TSW-104-08-G-T

Samtec TSW-105-08-G-D

Murata BLM31PG500SN1L

Murata LQG15HNR12J02B

NIC Components

Valpey Fisher VFAC3H-L-100MHz

Johnson Components

Tyco 6469169-1

Switchcraft RAPC722X

NIC Components

Part Number

NRC10ZOTRF

142-0710-851

NRC04J103TRF

NRC04Z0TRF

NRC04F64R9TRF

NRC06Z0TRF

Rev. A | Page 47 of 52

AD9287

Manufacturer’s

Item Qty. Reference Designator Device Package Value Manufacturer

35 15

36 8

37 4

38 3 R202, R203, R204 Resistor 402

39 1 R222 Resistor 402

40 1 R213 Resistor 402

41 1 R229 Resistor 402

42 2 R230, R319 Potentiometer 3-lead

43 1 R228 Resistor 402

44 1 R320 Resistor 402

45 8

46 4

47 4

48 11

49 1 R418 Resistor 402

50 1 R419 Resistor 402

51 1 R501 Resistor 603

52 2 R240, R241 Resistor 402

53 2 R242, R243 Resistor 402

54 1 S401 Switch SMD

55 5

56 2 U501, U503 IC SOT-223

R109, R111, R112, R123, R125, R126, R135, R138, R139, R148, R149, R150, R431, R432, R433

R108, R110, R121, R122, R134, R136, R146, R147

R161, R162, R163, R164

R307, R308, R309, R310, R407, R408, R409, R410

R305, R306, R405, R406

R316, R317, R415, R416

R245, R247, R249, R251, R253, R255, R257, R259, R261, R263, R265

T101, T102, T103, T104, T201

Resistor 402

Resistor 201 0 Ω, 1/20 W, 5% tol Panasonic

Transformer CD542

1 kΩ, 1/16 W, 1% tol

33 Ω, 1/16 W, 5% tol

499 Ω, 1/16 W, 1% tol

100 kΩ, 1/16 W, 1% tol

4.02 kΩ, 1/16 W, 1% tol

49.9 Ω, 1/16 W,

0.5% tol

4.99 kΩ, 1/16 W, 5% tol

10 kΩ, cermet trimmer potentiometer, 18-turn top adjust, 10%, 1/2 W

470 kΩ, 1/16 W, 5% tol

39 kΩ, 1/16 W, 5% tol

187 Ω, 1/16 W, 1% tol

374 Ω, 1/16 W, 1% tol

274 Ω, 1/16 W, 1% tol

4.75 kΩ, 1/16 W, 1% tol

261 Ω, 1/16 W, 1% tol

243 Ω, 1/16 W, 1% tol

100 Ω, 1/16 W, 1% tol

Light touch, 100GE, 5 mm

ADT1-1WT, 1:1 impedance ratio transformer

ADP33339AKC-1.8,

1.5 A, 1.8 V LDO regulator

NIC Components

Susumu RR0510R-49R9-D

NIC Components

BC Components

NIC Components

Panasonic EVQ-PLDA15

Mini-Circuits ADT1-1WT+

Analog Devices ADP33339AKCZ-1.8

Part Number

NRC04F1001TRF

NRC04J330TRF

NRC04F4990TRF

NRC04F1003TRF

NRC04F4121TRF

NRC04F4991TRF

CT94EW103

NRC04J474TRF

NRC04J393TRF

NRC04F1870TRF

NRC04F3740TRF

NRC04F2740TRF

ERJ-1GE0R00C

NRC04J472TRF

NRC04F2610TRF

NRC06F2610TRF

NRC04F2430TRF

NRC04F1000TRF

Rev. A | Page 48 of 52

AD9287

Manufacturer’s

Item Qty. Reference Designator Device Package Value Manufacturer

57 2 U301, U401 IC

LFCSP, CP-32

AD8332ACP, ultralow noise

Analog Devices AD8332ACPZ

precision dual

VGA 58 1 U504 IC SOT-223 ADP3339AKC-5 Analog Devices ADP3339AKCZ-5 59 1 U502 IC SOT-223 ADP3339AKC-3.3 Analog Devices ADP3339AKCZ-3.3 60 1 U201 IC

LFCSP, CP-48-1

AD9287BCPZ-100,

quad, 8-bit, 100

Analog Devices AD9287BCPZ-100

MSPS serial LVDS

1.8 V ADC

61 1 U203 IC SOT-23

ADR510ARTZ, 1.0 V,

Analog Devices ADR510ARTZ precision low noise shunt voltage reference

62 1 U202 IC

LFCSP

AD9515BCPZ Analog Devices AD9515BCPZ

CP-32-2

63 1 U403 IC

SC70,

NC7WZ07 Fairchild NC7WZ07P6X_NL

MAA06A

64 1 U404 IC

SC70,

NC7WZ16 Fairchild NC7WZ16P6X_NL

MAA06A

65 1 U402 IC 8-SOIC

Flash prog

Microchip PIC12F629-I/SN mem 1k × 14, RAM size 64 × 8, 20 MHz speed, PIC12F controller series

1

This BOM is RoHS compliant.

Part Number

Rev. A | Page 49 of 52

AD9287

OUTLINE DIMENSIONS

0.30

0.23

0.18 PIN 1

48

INDICATOR

1

BSC SQ

PIN 1 INDICATOR

7.00

0.60 MAX

37

36

0.60 MAX

1.00

0.85

0.80

12° MAX

SEATING PLANE

TOP

VIEW

0.80 MAX

0.65 TYP

0.50 BSC

COMPLIANT TO JEDEC STANDARDS MO-220-VKKD-2

6.75

BSC SQ

0.20 REF

0.50

0.40

0.30

0.05 MAX

0.02 NOM COPLANARITY

0.08

25

24

EXPOSED

PAD

(BOTTOM VIEW)

5.50 REF

13

5.25

5.10 SQ

4.95

12

0.25 MIN

Figure 71. 48-Lead Lead Frame Chip Scale Package [LFCSP_VQ]

7 mm × 7 mm Body, Very Thin Quad

(CP-48-1)

Dimensions shown in millimeters

ORDERING GUIDE

Model Temperature Range Package Description Package Option

AD9287BCPZ-100 AD9287BCPZRL7-1001−40°C to +85°C 48-Lead Lead Frame Chip Scale Package [LFCSP_VQ] Tape and Reel CP-48-1 AD9287-100EB Evaluation Board AD9287-100EBZ

1

Z = RoHS Compliant Part.

1

−40°C to +85°C 48-Lead Lead Frame Chip Scale Package [LFCSP_VQ] CP-48-1

1

Evaluation Board

Rev. A | Page 50 of 52

AD9287

NOTES

Rev. A | Page 51 of 52

AD9287

NOTES

Rev. A | Page 52 of 52

Analog Devices AD9287 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

FEATURES

APPLICATIONS

GENERAL DESCRIPTION

FUNCTIONAL BLOCK DIAGRAM

PRODUCT HIGHLIGHTS

REVISION HISTORY

SPECIFICATIONS

AC SPECIFICATIONS

DIGITAL SPECIFICATIONS

SWITCHING SPECIFICATIONS

TIMING DIAGRAMS

ABSOLUTE MAXIMUM RATINGS

THERMAL IMPEDANCE

ESD CAUTION

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

EQUIVALENT CIRCUITS

TYPICAL PERFORMANCE CHARACTERISTICS

THEORY OF OPERATION

ANALOG INPUT CONSIDERATIONS

Differential Input Configurations

Single-Ended Input Configuration

CLOCK INPUT CONSIDERATIONS

Clock Duty Cycle Considerations

Clock Jitter Considerations

Power Dissipation and Power-Down Mode

Digital Outputs and Timing

SDIO/ODM Pin

SCLK/DTP Pin

CSB Pin

RBIAS Pin

Voltage Reference

Internal Reference Operation

External Reference Operation

SERIAL PORT INTERFACE (SPI)

HARDWARE INTERFACE

MEMORY MAP

READING THE MEMORY MAP TABLE

RESERVED LOCATIONS

DEFAULT VALUES

LOGIC LEVELS

Power and Ground Recommendations Exposed Paddle Thermal Heat Slug Recommendations

EVALUATION BOARD

POWER SUPPLIES

INPUT SIGNALS

OUTPUT SIGNALS

DEFAULT OPERATION AND JUMPER SELECTION SETTINGS

ALTERNATIVE ANALOG INPUT DRIVE CONFIGURATION

OUTLINE DIMENSIONS

ORDERING GUIDE