Measurement Computing PC-CARD DAS16, Руководство пользователя

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PC-CARD-DAS16/16AO User's Guide Specifications
Analog output
Table 6. Analog output specifications
D/A converter type LTC1655
Resolution 16 bits
Number of channels 2
Configuration Voltage output, single-ended
Output range ±10 V
D/A pacing Software
Data transfer Programmed I/O
Throughput System dependent. Using the Universal Library programmed output
function (
cbAout
) in a loop in Visual Basic, a typical update rate of
1.5 kHz (±200 Hz) can be expected. The rate was measured on a
400 MHz Pentium II based PC.
Accuracy
Table 7. Accuracy specifications
Absolute accuracy ±12.0 LSB worst case error
Typical accuracy ±10.0 LSB worst case error
Table 8. Calibrated accuracy components
Gain error ±3.0 LSB max, ±1.0 LSB typ
Offset error ±1.5 LSB max, ±0.5 LSB typ
Integral linearity error ±20.0 LSB max, ±8.0 LSB typ
Differential linearity error ±1.0 LSB max, ±0.3 LSB typ
Each PC-CARD-DAS16/16AO is tested at the factory to assure the board’s overall error does not exceed
±12.0 LSB.
Total board error is a combination of gain, offset, integral linearity and differential linearity error. The
theoretical worst-case error of the board may be calculated by summing these component errors. Worst case
error is realized only in the unlikely event that each of the component errors are at their maximum level, and
causing error in the same direction. Although an examination of the chart and a summation of the maximum
theoretical errors shows that the board could theoretically exhibit a ±25.5 LSB error, our testing assures this
error is never realized in a board that we ship.
Typical accuracy is derived directly from the various component typical errors. This typical, maximum error
calculation for the PC-CARD-DAS16/16AO yields ±10.0 LSB. However, this again assumes that each of the
errors contributes in the same direction and the ±10.0 LSB specification is quite conservative.
Monotonicity Guaranteed monotonic over temperature
Analog output full-scale gain drift ±5.0 LSB/°C max
Analog output zero drift ±0.5 LSB/°C max
Overall analog output drift ±5.5 LSB/°C max
Slew rate ± 0.7 V/µs min
Current drive ±2 mA min
Output short-circuit duration Indefinite @ 12 mA
Output coupling DC
Output impedance 0.1 ohms max
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