AD9627 datasheet(52/77 Pages) AD

52 / 77 page

AD9627

Rev. B | Page 51 of 76

EVALUATION BOARD

The AD9627 evaluation board provides all of the support circuitry

required to operate the ADC in its various modes and configura-

tions. The converter can be driven differentially through a double

balun configuration (default) or optionally through the AD8352

differential driver. The ADC can also be driven in a single-ended

fashion. Separate power pins are provided to isolate the DUT

from the AD8352 drive circuitry. Each input configuration can

be selected by proper connection of various components (see

Figure 75 to Figure 92). Figure 74 shows the typical bench

characterization setup used to evaluate the ac performance of

the AD9627.

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.

See Figure 75 to Figure 79 for the complete schematics and

layout diagrams that demonstrate the routing and grounding

techniques that should be applied at the system level.

POWER SUPPLIES

This evaluation board comes with 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 output of the supply is a 2.1 mm inner diameter

circular jack that connects to the PCB at J16. Once on the PC

board, the 6 V supply is fused and conditioned before connection

to six low dropout linear regulators that supply the proper bias

to each of the various sections on the board.

External supplies can be used to operate the evaluation board

by removing L1, L3, L4, and L13 to disconnect the voltage

regulators supplied from the switching power supply. This enables

the user to individually bias each section of the board. Use P3

and P4 to connect a different supply for each section. At least

one 1.8 V supply is needed with a 1 A current capability for

AVDD and DVDD; a separate 1.8 V to 3.3 V supply is recom-

mended for DRVDD. To operate the evaluation board using the

AD8352 option, a separate 5.0 V supply (AMP VDD) with

a 1 A current capability is needed. To operate the evaluation board

using the alternate SPI options, a separate 3.3 V analog supply

(VS) is needed, in addition to the other supplies. The 3.3 V

supply (VS) should have a 1 A current capability, as well. Solder

Jumper SJ35 allows the user to separate AVDD and DVDD,

if desired.

INPUT SIGNALS

When connecting the clock and analog source, use clean signal

generators with low phase noise, such as the Rohde & Schwarz

SMA100A signal generators or the equivalent. Use 1 m long,

shielded, RG-58, 50 Ω coaxial cable for making connections to the

evaluation board. Enter the desired frequency and amplitude for

the ADC. The AD9627 evaluation board from Analog Devices,

Inc., can accept a ~2.8 V p-p or 13 dBm sine wave input for the

clock. When connecting the analog input source, it is recom-

mended that a multipole, narrow-band, band-pass filter with 50 Ω

terminations be used. Band-pass filters of this type are available

from TTE, Allen Avionics, and K&L Microwave, Inc. Connect the

filter directly to the evaluation board, if possible.

OUTPUT SIGNALS

The parallel CMOS outputs interface directly with the Analog

Devices standard ADC data capture board (HSC-ADC-EVALCZ).

For more information on the ADC data capture boards and their

optional settings, visit www.analog.com/FIFO.

USB

CONNECTION

AD9627

EVALUATION BOARD

12-BIT

PARALLEL

CMOS

12-BIT

PARALLEL

CMOS

HSC-ADC-EVALCZ

FPGA BASED

DATA

CAPTURE BOARD

PC RUNNING

VISUAL ANALOG

AND SPI

CONTROLLER

SOFTWARE

1.8V

–+

5.0V

3.3V

6V DC

2A MAX

WALL OUTLET

100V TO 240V AC

47Hz TO 63Hz

SWITCHING

POWER

SUPPLY

–+

3.3V

–+

3.3V

SPI

ROHDE & SCHWARZ,

SMA100A,

2V p-p SIGNAL

SYNTHESIZER

CLK

ROHDE & SCHWARZ,

SMA100A,

2V p-p SIGNAL

SYNTHESIZER

AINB

BAND-PASS

FILTER

ROHDE & SCHWARZ,

SMA100A,

2V p-p SIGNAL

SYNTHESIZER

AINA

BAND-PASS

FILTER

Figure 74. Evaluation Board Connection

AD9627 Datasheet(PDF) 52 Page - Analog Devices

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