SLUUCA6 October 2021 BQ27Z746
When the sleep conditions are met, the device goes into SLEEP mode with periodic wakeups to reduce power consumption. The device returns to NORMAL mode if any exit sleep condition is met, but waits until the 4-second current measurement completes to avoid losing passed charge.
By setting DA Configuration[WAKE_SLP_1SEC] = 1, the device can be configured to exit to NORMAL on the next 1-second boundary and stop the present current measurement. However, this configuration is not recommended, especially if SLEEP mode is frequently entered and exited. The device always exits SLEEP to NORMAL on the next 1-second boundary for OperationStatus()[SDM] and OperationStatus()[CAL], which are used to enter SHUTDOWN and calibration mode.
Firmware processing is minimized by reducing the number of calculations. Some calculations are performed less frequently: only after voltage and temperature are measured. These less frequent calculations include updating lifetime data, the voltage and temperature range of the advanced charge algorithm, and averaged values such as AveragePower().
Status | Condition | Action |
---|---|---|
Activate | DA Config[SLEEP] = 1 AND |Current()| ≤ Sleep Current AND Voltage Time > 0 AND Device in RELAX mode |
The device goes to SLEEP mode. The device wakes up every Voltage Time to measure voltage and temperature.(1) The device continues to coulomb count and update current every 4 s. Tip: Synchronize these two times to save power. |
Exit | DA Config[SLEEP] = 0 OR |Current()| > Sleep Current OR Voltage Time = 0 OR (Hardware-based IWAKE threshold surpassed AND DA Configuration[IWAKE_EXIT] = 1) OR OperationStatus()[SDM] = 1 OR OperationStatus()[CAL] = 1 OR SafetyAlert() ≠ 0 |
Return to NORMAL mode |
The configuration options for SLEEP are in the following data flash.
Class | Subclass | Name | Type | Min | Max | Default | Unit | Description |
---|---|---|---|---|---|---|---|---|
Power | Sleep | Sleep Current | I2 | 0 | 32767 | 15 | mA | |Current()| threshold to enter SLEEP mode |
Power | Sleep | Voltage Time | U1 | 1 | 20 | 5 | s | Voltage and temperature sampling period in SLEEP mode |