Datasheet

AD9734/AD9735/AD9736
Rev. A | Page 49 of 72
The full-scale output current range is approximately 10 mA to
30 mA for register values from 0x000 to 0x3FF. The default
value of 0x200 generates 20 mA full scale. The typical range is
shown in
Figure 89.
35
30
25
20
I
FS
(mA)
15
10
5
0
0 200 400 600 800
DAC GAIN CODE
1000
04862-087
Figure 89. I
FS
vs. DAC Gain Code
Always connect a 10 kΩ resistor from the I120 pin to ground
and use the digital controls to vary the full-scale current. The
AD973x is not a multiplying DAC. Applying an analog signal to
I120 is not supported.
VREF (Pin C14) must be bypassed to ground with a 1 nF
capacitor. The band gap voltage is present on this pin and can
be buffered for use in external circuitry. The typical output
impedance is near 5 kΩ. If desired, an external reference can be
used to overdrive the internal reference by connecting it to the
VREF pin.
IPTAT (Pin D14) is used for factory testing. Leave this pin
floating.