© National Instruments Corporation
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DAQCard-500 User Manual
Appendix A
Specifications
This appendix lists the specifications of the DAQCard-500. These specifications are typical at 25° C unless
otherwise specified. The operating temperature range is 0° to 70° C.
Analog Input
Input Characteristics
Number of channels ..................................................... 8 single-ended
Type of ADC ................................................................Successive approximation
Resolution..................................................................... 12 bits, worst-case code range -2,021 to +2,020 (due to
software calibration)
Maximum sampling rate............................................... 50 kS/s, 25 kS/s sustained under DOS, 10 kS/s sustained
under Windows 3.x
Input signal ranges ....................................................... ±5 V
Input coupling ..............................................................DC
Overvoltage protection................................................. ±25 V powered on, ±25 V powered off
Inputs protected..................................................... ACH<0..7>
FIFO buffer size ........................................................... 16 samples
Data transfers ............................................................... Interrupts, programmed I/O
Transfer Characteristics
Relative accuracy ........................................................±1.5 LSB typ, ±2.5 LSB max
DNL ............................................................................. ±0.7 LSB typ, ±1 LSB max
INL ............................................................................... ±0.7 LSB typ, ±1 LSB max
No missing codes ......................................................... 12 bits, guaranteed
Offset error
After software calibration ..................................... ±1 LSB
Before software calibration................................... ±8 LSB typ, ±12 LSB max
Gain error (relative to calibration reference)
After software calibration ..................................... ±0.045% of reading typ, ±0.09% max
Before software calibration................................... ±0.87% of reading typ, ±1.5% max
Amplifier Characteristics
Input impedance ........................................................... 1 G in parallel with 40 pF
Dynamic Characteristics
Settling time to ±0.024% (±1 LSB) for
full-scale step ............................................................... 20 µs
System noise................................................................. 0.5 LSBrms
Stability
Recommended warm-up time ......................................15 min
Offset temperature coefficient......................................10 ppm/° C max
Gain temperature coefficient ........................................15 ppm/° C max