National Instruments Low-Cost Multifunction I/O Board for ISA Lab-PC+ - Manual (Page 85)

Specifications Appendix A
Lab-PC+ User Manual A-4 © National Instruments Corporation
Analog Output
Output Characteristics
Number of channels ......................................
2
Resolution ..................................................... 12 bits, 1 in 4,096
Type of DAC................................................. Double-buffered multiplying
Data transfers ................................................ Interrupts, programmed I/O
Transfer Characteristics
Relative accuracy (INL) ................................
bipolar range ...........................................
±
0.25 LSB typ,
±
0.5 LSB max
DNL ..............................................................
±
0.25 LSB typ,
±
0.75 LSB max
Monotonicity ................................................. 12 bits, guaranteed
Offset error ....................................................
After calibration ...................................... Adjustable to 0 V
Before calibration....................................
±
37 mV max
Gain error (relative to internal reference)
After calibration ...................................... Adjustable to 0%
Before calibration....................................
±
0.5% of reading (3,900 ppm) max
Voltage Output
Ranges ...........................................................
±
5 V, or 0 to 10 V, jumper selectable
Output coupling............................................. DC
Output impedance ......................................... 0.2
Ω
max
Current drive .................................................
±
2 mA max
Protection ...................................................... Short to AGND
Power on state ............................................... 0 V for
±
5 V range, 5 V for 0 to 10 V range
Dynamic Characteristics
Settling time to FSR for 10 V step ................
5
µ
s
Slew rate........................................................ 10 V/
µ
s
Stability
Offset temperature coefficient ......................
±
30
µ
V/
°
C
Gain temperature coefficient
internal reference.....................................
±
10 ppm/
°
C
Explanation of Analog Output Specifications
Relative accuracy in a D/A system is the same as nonlinearity, because no uncertainty is added
due to code width. Unlike an ADC, every digital code in a D/A system represents a specific
analog value rather than a range of values. The relative accuracy of the system is therefore
limited to the worst-case deviation from the ideal correspondence (a straight line), excepting
noise. If a D/A system has been calibrated perfectly, then the relative accuracy specification
reflects its worst-case absolute error.