Filter
Top Products
Appendix B Digitizer Basics
©
National Instruments Corporation B-5 NI 5911 User Manual
to Appendix A, Specifications, for the maximum input voltage for
your NI 5911 device. Figure B-5 shows that a gain of 5 is the best
setting to digitize a 300 mV, 1 MHz sine wave without clipping the
signal.
Figure B-5. Dynamic Range of an 8-Bit ADC with Three Different Gain Settings
+127 LSB
+38.4 LSB
–38.4 LSB
0 LSB
–128 LSB
+127 LSB
+7 LSB
–8 LSB
0 LSB
–128 LSB
+127 LSB
+153 LSB
–154 LSB
0 LSB
–128 LSB
Acquired Signal
a. Gain = 1, Input Range
±5 V, Number of LSBs = 15
b. Gain = 5, Input Range ±1 V, Number of LSBs = 77
c. Gain = 20, Input Range ±250 mV, Number of LSBs = 307.2
CBIHWum.book Page 5 Thursday, October 29, 1998 1:56 PM