ZHCSKD9 October 2019 ADS1235-Q1
PRODUCTION DATA.
The ADC incorporates an internal low-voltage monitor of the reference voltage. As shown in Figure 45 and Figure 46, the REFL_ALM bit of the STATUS byte asserts if the reference voltage (VREF = VREFP – VREFN) falls below 0.4 V. The alarm is read-only and resets at the next conversion after the low reference condition is no longer present.
Use the reference monitor to detect a missing or failed reference voltage. To implement detection of a missing reference, use a 100-kΩ resistor across the reference inputs. If either reference input is disconnected, the resistor biases the differential reference input toward 0 V so that the reference monitor detects the disconnected reference.