SLUUCO9A April 2023 – November 2023 BQ28Z620
To minimize power consumption and avoid draining the battery, the device can be configured to shut down at a programmable stack voltage threshold.
| Status | Condition | Action |
|---|---|---|
| Enable | Min cell voltage < Shutdown Voltage | OperationStatus()[SDV] = 1 |
| Trip | Min cell voltage continuous < Shutdown Voltage for Shutdown Time | Turn DSG FET off |
| Shutdown | Voltage at PACK terminal < Charger Present Threshold AND Current() ≤ 0 | Send device into SHUTDOWN mode |
| Exit | Voltage at PACK terminal > VSTARTUP OR Min cell voltage > Shutdown Voltage if not in SHUTDOWN mode | OperationStatus()[SDV] = 0 Return to NORMAL mode. When booting from a SHUTDOWN mode, the gauge will take an OCV measurement of the cells before the FETs are enabled. |
The device goes through a full reset when exiting from SHUTDOWN mode, which means the device will reinitialize. On power up, the gauge checks certain special memory locations. If the memory checksum is incorrect, or if either the gauge of the AFE watchdog has been triggered, the gauge will do a full reset.
If the memory checksum is good, for example in the case of a short power glitch, the gauge will do a partial reset. The initialization is faster in partial reset, and certain memory data will not be reinitialized (for example, all SBS registers, last known FET state, last ADC and CC readings, and so on) and so a partial reset is usually transparent to the host.