4.2.4 Measurement Ranges and Accuracy
The XAM has four measurement ranges. These are defined by two shunt resistors and two gain stages.
| Measurement Range | Hardware | Resolution | Accuracy | Comments |
|---|---|---|---|---|
| Range 1 | Low current shunt and high gain stage | 20 nA | 1 LSB ±1% | Accuracy will decrease below 1μA. Typical accuracy for 300nA is 1 LSB ± 10%. |
| Range 2 | Low current shunt and low gain stage | 150 nA | 1 LSB ±1% | |
| Range 3 | High current shunt and high gain stage | 10 μA | 1 LSB ±1% | |
| Range 4 | High current shunt and low gain stage | 100 μA | 1 LSB ±1% | Accuracy will decrease above 100 mA. Typical accuracy is 1 LSB ±5% at 400 mA. Maximum current is 400 mA. |
The ranges are automatically switched by the XAM to achieve the best measurement results and the currently active range is visualized in the Data Visualizer front-end tool. The maximum voltage drop over the shunt resistor is 100 mV, and the XAM switches the range automatically before reaching this limit.