Functional description

STC3115

12/31

DocID023755 Rev 4

6.1.3

Internal temperature monitoring

The chip temperature (close to the battery temperature) is measured using one conversion

cycle of the A/D converter every 16 s.

conversion cycle time is 250 ms. Resolution is 1° C and range is -40 to +125 °C.

The result is stored in the REG_TEMPERATURE register (see Table 12).

6.1.4

Current sensing

Voltage drop across the sense resistor is integrated during a conversion period and input to

the 14-bit sigma-delta A/D converter.

Using the 32768 Hz internal clock, the conversion cycle time is 500 ms for a 14-bit

resolution. The LSB value is 5.88 µV. The A/D converter output is in two’s complement

format.

When a conversion cycle is completed, the result is added to the Coulomb counter

accumulator and the number of conversions is incremented in a 16-bit counter.

The current register is updated only after the conversion closest to the voltage conversion

(that is: once per 4-s measurement cycle). The result is stored in the REG_CURRENT

register (see Table 12).