Analog Output; Analog Output Circuitry - DAQ DAQCard-1200 User Manual

Chapter 4 Theory of Operation
Note If you use external conversions for single-channel acquisitions, the maximum
sampling rate is 90 kS/s.

Analog Output

DAC0OUT
AGND
EXTUPDATE*
DAC1OUT

Analog Output Circuitry

DAQCard-1200 User Manual
The recommended acquisition rates in Table 4-2 assume that voltage levels
on all the channels included in the scan sequence are within range for the
given gain and are driven by low-impedance sources.
The DAQCard-1200 has two channels of 12-bit D/A output. Each AO
channel can provide unipolar or bipolar output. The DAQCard-1200 also
contains timing circuitry for waveform generation timed either externally
or internally. Figure 4-5 shows the AO circuitry.
DAC0
5 V Internal
External Update
Reference
DAC1
Dual DAC Chip
Figure 4-5. Analog Output Circuitry
Each AO channel contains a 12-bit DAC. The DAC in each AO channel
generates a voltage proportional to the 5 V reference (provided in the Dual
DAC chip) multiplied by the 12-bit digital code loaded into the DAC. The
voltage output from the two DACs is available at the DAQCard-1200 I/O
connector DAC0OUT and DAC1OUT pins.
You can program each DAC channel for a unipolar voltage output or a
bipolar voltage output range. A unipolar output gives an output voltage
Two's Complement
DAC0WRT
Data
8
Counter
A2
DAC1WRT
Two's Complement
4-10
Data
8
Control
Signal
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