Appendix B - Noise and Resolution Tables [UE9 Datasheet]
The following tables provide typical noise levels of the UE9 under ideal conditions. The resulting voltage resolution is then calculated based on the noise levels. Also see the LJTick-InAmp datasheet which provides similar tables with the instrumentation amplifier installed.
Measurements were taken with AIN0 connected to GND with a short jumper wire, or from internal ground channel #15. Similar results were obtained with other quiet signals such as a 2.048 reference (REF191 from Analog Devices), a 1.5 volt D-cell battery, and a temperature sensor (LM34CAZ from National Semiconductor).
All “counts” data are aligned as 24-bit values. To equate to counts at a particular resolution (Res) use the formula counts/(2^(24-Res)). For instance, with the UE9 set to 12-bit resolution and the 0-5 volt range, there are 8192 counts of noise when looking at 24-bit values. To equate this to 12-bit data, we take 8192/(2^12) which equals 2 counts of noise when looking at 12-bit values.
Noise-free data is determined by taking 128 readings and subtracting the minimum value from the maximum value.
RMS and Effective data are determined from the standard deviation of 128 readings. In other words, the RMS data represents most readings, whereas noise-free data represents all readings.
Table B-1. Resolution and noise table
Resolution = 0-12 |
|
|
|
|
|
|
Range | Peak-To-Peak Noise | Noise-Free Resolution | Noise-Free Resolution | RMS Noise | Effective Resolution | Effective Resolution |
volts | counts | bits | µV | counts | bits | µV |
±5 | 8192 | 11 | 4,883 | 2200 | 12.8 | 1,402 |
0-5 | 8192 | 11 | 2,441 | 2200 | 12.8 | 701 |
0-2.5 | 20480 | 9.7 | 3,006 | 4100 | 12 | 610 |
0-1.25 | 36864 | 8.8 | 2,804 | 7800 | 11.1 | 569 |
0-0.63 | 69632 | 7.9 | 2,638 | 14500 | 10.1 | 574 |
|
|
|
|
|
|
|
Resolution = 14 |
|
|
|
|
|
|
Range | Peak-To-Peak Noise | Noise-Free Resolution | Noise-Free Resolution | RMS Noise | Effective Resolution | Effective Resolution |
volts | counts | bits | µV | counts | bits | µV |
±5 | 2816 | 12.5 | 1,726 | 550 | 14.9 | 327 |
0-5 | 2816 | 12.5 | 863 | 550 | 14.9 | 164 |
0-2.5 | 4864 | 11.8 | 701 | 940 | 14.1 | 142 |
0-1.25 | 8448 | 11 | 610 | 1650 | 13.3 | 124 |
0-0.63 | 16384 | 10 | 615 | 3300 | 12.3 | 125 |
|
|
|
|
|
|
|
Resolution = 16 |
|
|
|
|
|
|
Range | Peak-To-Peak Noise | Noise-Free Resolution | Noise-Free Resolution | RMS Noise | Effective Resolution | Effective Resolution |
volts | counts | bits | µV | counts | bits | µV |
±5 | 720 | 14.5 | 432 | 140 | 16.9 | 82 |
0-5 | 720 | 14.5 | 216 | 140 | 16.9 | 41 |
0-2.5 | 1200 | 13.8 | 175 | 230 | 16.2 | 33 |
0-1.25 | 2224 | 12.9 | 164 | 400 | 15.4 | 29 |
0-0.63 | 4256 | 11.9 | 165 | 775 | 14.4 | 29 |
|
|
|
|
|
|
|
Resolution = 17 |
|
|
|
|
|
|
Range | Peak-To-Peak Noise | Noise-Free Resolution | Noise-Free Resolution | RMS Noise | Effective Resolution | Effective Resolution |
volts | counts | bits | µV | counts | bits | µV |
±5 | 352 | 15.5 | 216 | 75 | 17.8 | 44 |
0-5 | 352 | 15.5 | 108 | 75 | 17.8 | 22 |
0-2.5 | 620 | 14.7 | 94 | 120 | 17.1 | 18 |
0-1.25 | 1060 | 14 | 76 | 210 | 16.3 | 15 |
0-0.63 | 2068 | 13 | 77 | 400 | 15.4 | 15 |
|
|
|
|
|
|
|
Resolution = 18+ (UE9-Pro) |
|
|
|
|
|
|
Range | Peak-To-Peak Noise | Noise-Free Resolution | Noise-Free Resolution | RMS Noise | Effective Resolution | Effective Resolution |
volts | counts | bits | µV | counts | bits | µV |
±5 | 110 | 17.2 | 66 | 20 | 19.7 | 12 |
0-5 | 90 | 17.5 | 27 | 17 | 19.9 | 5 |