SLUSE91B September 2020 – January 2022 BQ769142
PRODUCTION DATA
At initial power up of the BQ769142 device from a SHUTDOWN state, the device progresses through a sequence of events before entering NORMAL mode operation. These are described below for an example configuration, with approximate timing shown for the cases when [FASTADC] = 0 and [FASTADC] = 1.
Step | Comment | FASTADC Setting | Time (relative to wakeup event) |
---|---|---|---|
Wakeup event | Either the TS2 pin is pulled low, or the LD pin is pulled up, triggering the device to exit SHUTDOWN mode. | 0, 1 | 0 |
REG1 powered | This was measured with the OTP programmed to autonomously power the REG1 LDO. | 0, 1 | 20 ms |
INITSTART asserted | This was measured with the OTP programmed to provide the INITSTART bit in the Alarm signal on the ALERT pin. | 0, 1 | 23 ms |
INITCOMP and ADSCAN asserted | This was measured with the OTP programmed to provide the INITCOMP and ADSCAN bits in the Alarm signal on the ALERT pin. | 0 | 88 ms |
1 | 58 ms | ||
FULLSCAN asserted | This was measured with the OTP programmed to provide the FULLSCAN bit in the Alarm signal on the ALERT pin. | 0 | 221 ms |
1 | 129 ms | ||
FETs enabled | This was measured with the OTP programmed to autonomously enable FETs. | 0 | 282 ms |
1 | 284 ms |
Figure 16-5 shows an example of an oscilloscope plot of a startup sequence with the device configured in OTP with [FASTADC] = 1, [FET_EN] = 1 for autonomous FET control, setup to use three thermistors, and providing the [INITCOMP] flag on the ALERT pin. The TS2 pin is pulled low to initiate device wakeup from SHUTDOWN.