SLUSE13A January 2020 – May 2021 BQ76952
The BQ76952 voltage measurements are taken in a measurement loop that consists of multiple measurement slots. All 16 cell voltages are measured on each loop, then one slot is used for one of the VC16 or PACK or LD pin voltages, one slot is used for internal temperature or Vref or VSS measurement, then up to three slots are used to measure thermistors or multifunction pin voltages (ADCIN functionality). Over the course of three loops, a full set of measurements is completed. One measurement loop consists of either 18 (if no thermistors or ADCIN are enabled), 19 (if one thermistor or ADCIN is enabled), 20 (if two thermistors or ADCIN are enabled), or 21 (if three or more thermistors or ADCIN are enabled) measurement slots.
The speed of a measurement loop can be controlled by settings. Each voltage measurement (slot) takes 3 ms (or 1.5 ms depending on setting), so a typical measurement loop with 21 slots per loop takes 63 ms (or 31.5 ms depending on setting). If measurement data is not required as quickly, the timing for the measurement loop can be programmed to slower speeds, which injects idle slots in each loop after the measurement slots. Using slower loop cycle time will reduce the power dissipation of the device when in NORMAL mode.