Analog Output Calibration - Omega PCI-DAS1602/16 User Manual

7.2 Analog Output Calibration

The analog output circuits are calibrated for both gain and offset. Coarse and Fine offset adjust-
ments are made in the output buffer section. The tuning range of these adjustments allows for
maximum DAC and output buffer offsets. Coarse and Fine gain calibration is performed via
adjustments to the DAC reference.
Note that there are no references associated with the DAC calibration - a fully calibrated ADC set
to the respective DAC range is used as the measurement system. Sub-ranging of the ADC is used
to ensure highly accurate offset adjustments.
The calibration scheme for the Analog Out section is shown in Figure 2 below. This circuit is
duplicated for both DAC0 and DAC1 Figure 2
Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac
(Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse)
Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac
(Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine)
Analog-Out
16
DAC
Ref
Gain Adj Gain Adj Gain Adj
Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac
(Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse) (Coarse)
Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac Trim Dac
(Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine) (Fine)
Figure 2
Page 12
Analog Out
Offset Adj