AD9754

–19–

REV. A

Figure 37 shows the AD9754 reconstructing a wideband, or

W-CDMA test vector with a bandwidth of 5 MHz, centered at

15.625 MHz and being sampled at 62.5 MSPS. ACP for the

given test vector is measured at 70 dB.

FREQUENCY – MHz

–30

–50

–110

–70

–90

13.125

15.625

18.125

–40

–60

–80

–100

–20

–120

Figure 37. CDMA Signal, Sampled at 65 MSPS, Adjacent

Channel Power >70 dB

AD9754 EVALUATION BOARD

General Description

The AD9754-EB is an evaluation board for the AD9754 14-bit

DAC converter. Careful attention to layout and circuit design,

combined with a prototyping area, allows the user to easily and

effectively evaluate the AD9754 in any application where high

resolution, high speed conversion is required.

This board allows the user the flexibility to operate the AD9754

in various configurations. Possible output configurations in-

clude transformer coupled, resistor terminated, inverting/

noninverting and differential amplifier outputs. The digital inputs

are designed to be driven directly from various word generators

with the onboard option to add a resistor network for proper

load termination. Provisions are also made to operate the

AD9754 with either the internal or external reference or to

exercise the power-down feature.

Refer to the application note AN-420 for a thorough description

and operating instructions for the AD9754 evaluation board.

AD9754

(“I DAC”)

AD9754

(“Q DAC”)

IOUTA

IOUTB

QOUTA

QOUTB

DCOM

FSADJ

REFIO

SLEEP

1.9k

0.1 F

CLK

Q DATA

INPUT

I DATA

INPUT

DVDD

AVDD

100W

500

100

100

500

500

500

500

500

500

634

+3V

IIPP

IIPN

IIQP

IIQN

AD6122

REFLO

ACOM

REFLO

AVDD

REFIO

FSADJ

2k

220

U1

U2

AVDD

LATCHES

500

DAC

DAC

LATCHES

100

2

TEMPERATURE

COMPENSATION

GAIN

CONTROL

SCALE

FACTOR

REFIN

VGAIN

GAIN

CONTROL

LOIPP

LOIPN

TXOPP

TXOPN

PHASE

SPLITTER

MODOPP

MODOPN

Figure 36. CDMA Transmit Application Using AD9754