Datasheet

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
REFERENCE LEVEL – dBm
–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
FSADJREFIO SLEEP
R
SET2
1.9kV
0.1mF
CLK
Q DATA
INPUT
I DATA
INPUT
DVDD
AVDD
100W
500V
100V
C
FILTER
100V
500V
500V
500V
500V
500V
500V
634V
+3V
IIPP
IIPN
IIQP
IIQN
AD6122
REFLO
ACOM
REFLOAVDD
REFIO
FSADJ
R
SET1
2kV
R
CAL
220V
U1
U2
AVDD
LATCHES
500V
DAC
DAC
LATCHES
100V
42
TEMPERATURE
COMPENSATION
GAIN
CONTROL
SCALE
FACTOR
REFIN
VGAIN
GAIN
CONTROL
LOIPP
LOIPN
TXOPP
TXOPN
V
CC
V
CC
PHASE
SPLITTER
MODOPP
MODOPN
Figure 36. CDMA Transmit Application Using AD9754