A 16-bit integrating ADC, commonly referred to as the coulomb counter (CC), provides measurements of accumulated charge across the current sense resistor. The integration period for this reading is 250 ms.

The CC may be operated in one of two modes: ALWAYS ON and 1-SHOT.

• In ALWAYS ON mode, the CC runs at 100%, gathering a fresh reading every 250 ms. The conclusion of each reading sets the CC_READY bit, which toggles the ALERT pin high to inform the microcontroller that a new reading is available. To enable Always On mode, set [CC_EN] = 1.
• In 1-SHOT mode, the CC performs a single 250-ms reading, and similarly sets the CC_READY bit when completed. This mode is intended for non-gauging usages, where the host simply desires to check the pack current.

  To enable a 1-SHOT reading, ensure [CC_EN] = 0 and set [CC_ONESHOT] = 1.

The fullscale range of the CC is ± 270 mV, with a max recommended input range of ± 200 mV, thus yielding an LSB of approximately 8.44 µV.

The following equation shows how to convert the 16-bit CC reading into an analog voltage if no board-level calibration is performed: