JAJSIU8B June 2015 – April 2020 ADS131E08S
The ADS131E08S has integrated comparators to detect out-of-range conditions on the input signals. The basic principle is to compare the input voltage against a threshold voltage set by a 3-bit digital-to-analog converter (DAC) based off the analog power supply. The comparator trigger threshold level is set by the COMP_TH[2:0] bits in the FAULT register.
If the ADS131E08S is powered from a ±2.5-V supply and COMP_TH[2:0] = 000 (95% and 5%), the high-side trigger threshold is set at 2.25 V [equal to AVSS + (AVDD – AVSS) × 95%] and the low-side threshold is set at –2.25 V [equal to AVSS + (AVDD – AVSS) × 5%]. The threshold calculation formula applies to unipolar as well as to bipolar supplies.
A fault condition can be detected by setting the appropriate threshold level using the COMP_TH[2:0] bits. To determine which of the inputs is out of range, read the FAULT_STATP and FAULT_STATN registers individually or read the FAULT_STATx bits as part of the output data stream; see the Data Output (DOUT) section.