SBAS784A January 2019 – May 2019 ADS1260-Q1 , ADS1261-Q1
PRODUCTION DATA.
The PGA has voltage monitors to provide indication when the PGA is overloaded. In overload condition, the conversion data are no longer valid. If either the PGA positive or negative output exceeds AVDD – 0.2 V, the high alarm bit is set (PGAH_ALM). Similarly, if either PGA positive or negative output is less than AVSS + 0.2 V, the low alarm bit is set (PGAL_ALM). The monitor alarm state is read in the STATUS byte. The monitor alarm is read-only and automatically resets at the start of the next conversion cycle after the overload condition is cleared. The monitor diagram and threshold values are shown in Figure 12 and Figure 13.
The PGA monitors consist of fast-responding voltage comparators. Comparator operation is disabled during multiplexer changes to minimize the false triggering during these input switching events. However, it is possible the monitors can detect other transient overload conditions that may occur after gain changes, sensor connection changes, and so on.