SLASEM6C October 2017 – October 2020 TAS2770
A 12-bit SAR ADC monitors VBAT voltage and die temperature. The results of these conversions are available via register readback (VBAT_CNV[11:0] and TMP_CNV[7:0] registers respectively). VBAT voltage conversions are also used by the limiter and brown out prevention features.
The ADC runs at a fixed 667 kHz sample rate (1.5 µs per conversion) interleaved between VBAT voltage and die temperature measurements. This gives an effective sample rate of 333 kHz (3 µs per conversion) with a latency of 1 sample (1.5 µs). This gives a worst case measurement latency of 4.5 µs. Actual VBAT voltage is calculated by dividing the VBAT_CNV[11:0] register by 256. Actual die temperature is calculated by dividing the TMP_CNV[11:0] register by 16 and then subtracting 93.
|VBAT_CNV[11:0]||VBAT Voltage (V)|
|TMP_CNV[11:0]||Die Temperature (°C)|