Measurement Specialties PC-CARD-DAS16/12AO manual Crosstalk, Noise performance

PC-CARD-DAS16/12AO User's Guide						Specifications
			Table 3. Calibrated accuracy specifications
	Range	Gain Error		Offset Error	DLE (Note 1)	ILE (Note 1)
	All ranges	±1.0 max		±1.0 max	±1.0 max	±1.0 max

Note 1: These are the intrinsic specifications of the ADC. Software calibration may introduce a small additional amount of linearity error.

As shown in Table 3, total board error is a combination of gain, offset, differential linearity and integral linearity error. The theoretical worst-case error of the board may be calculated by summing these component errors. Worst case errors are realized only in the unlikely event that each of the component errors are at their maximum level, and causing error in the same direction.

Analog input full-scale gain drift	±0.66 LSB/°C max
Analog input zero drift	±0.61 LSB/°C max
Overall analog input drift	±1.27 LSB/°C max
Common mode range	±10 V min
CMRR @ 60 Hz	-72 dB min
Input leakage current	±20 nA max
Input impedance	10 MOhms min
Absolute maximum input voltage	+55/-40 V (Fault Protected via Input Mux)

Crosstalk

Crosstalk is defined here as the influence of one channel upon another when scanning two channels at the maximum rate. A full scale 100 Hz triangle wave is input on channel 1; channel 0 is tied to analog ground at the connector. The table below summarizes the influence of channel 1 on channel 0 with the effects of noise removed. The residue on channel zero is described in LSB's.

Table 4. Channel to channel crosstalk specifications

Condition	Crosstalk	Per channel Rate	ADC Rate
All ranges	1LSB pk-pk	50 kHz	100 kHz

Noise performance

Table 5 summarizes the noise performance for the PC-CARD-DAS16/12AO. Noise distribution is determined by gathering 50 K samples at 100 kHz with inputs tied to ground at the user connector.

Table 5. Noise performance specifications

Range	% within ±2 LSBs	% within ±1 LSB	Typical LSBrms*	Max LSBrms*
0 to 1.250 V	100%	99%	0.61	0.90
All other ranges	100%	100%	0.45	0.75

* RMS noise is defined as the peak-to-peak bin spread divided by 6.6.

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