IBM DAS16AO manual Analog output

PC-CARD-DAS16/16AO User's GuideSpecifications

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

21