Hibernate mode minimizes the quiescent current and provides autonomous wakeup.

The following hibernate modes are available:
  • Hibernate – BOOST is running in Ultra-Low Power mode and LDOSW is available.
  • Hibernate_PT – BOOST is set to Pass-through mode (VINT=VBAT). This mode can only be used when battery voltage is high enough (VBAT > VINTBOR) to supply the chip directly without boosting. Battery and VINT voltage are not monitored and LDOSW is disabled.

Both Hibernate modes use more power than Ship mode, but provide faster wakeup (tSHPHLD_HIB). Ship mode provides the lowest power consumption and slowest wakeup. Hibernate_PT mode is the third lowest power consumption mode (IQHIB_PT).

The following are alternative ways to exit both Hibernate modes:
  • Exit automatically through the wakeup timer
  • SHPHLD pin wakeup. The pin debounce time is adjustable through register DEBOUNCE.
Note: The wakeup timer must be set for longer than tPWRDN.

Hibernate mode

The device enters Hibernate mode through register TASKS_HIBER. In Hibernate mode, BOOST is running (VINT > VBAT), VOUT is discharged to AVSS1, but LDOSW is possibly ON. This mode has higher power consumption than Hibernate_PT.

Wakeup is fast as VINT is already at the target voltage level. Register content remains.

Hibernate_PT mode

The device enters Hibernate_PT mode through register TASKS_HIBERPT. BOOST is set to Pass-through mode. VOUT is discharged to AVSS1 and LDOSW is disabled.

Upon wakeup, the device executes full power-up sequence including register reset.