SLASF96 April 2024 AFE20408
PRODUCTION DATA
The device provides independent out-of-range detection for each of the ADC inputs. Figure 6-10 shows the out-of-range detection block. When the measurement is out-of-range, the corresponding alarm bit in the alarm status register is set to flag the out-of-range condition. The values in the ADC high limit and low limit registers define the upper and lower bound thresholds for the ADC inputs.
To prevent false alarms, an alarm event is only registered when the monitored signal is out of range for an N number of consecutive conversions. If the monitored signal returns to the normal range before N consecutive conversions, an alarm event is not issued. The false alarm factor, N, for the ADC input alarms can be configured by writing to the FALR_ADC, FALR_SENSE and/or FALR_TMP fields in the ADC_GEN_CFG register (located in the ADC Configuration register page).
If an ADC input signal is out of range and the alarm is enabled, the corresponding alarm bit is set to 1. However, the alarm condition is cleared only when the conversion result returns either a value lower than the high limit register setting or higher than the low limit register setting by the number of codes specified in the ADC hysteresis setting (see Figure 6-11). The hysteresis for ADC alarms can be set by writing to bits 7 through 0 in the ADC_HYST_0 register. Hysteresis can also be set for the SENSE input alarms, by writing to bits 7 through 0 in the ADC_HYST_1 register. In both these cases, the hysteresis is a programmable value between 0 LSB to 127 LSB.