If VCC is connected to VBAT through a
switch, the MCU LDO cannot be used to power the MCU because the MCU LDO is not powered
when the switch disconnects power to VCC. There are three options to power the MCU:
- Connect the MCU to the battery and VMCU to VCC.
- Use an external LDO to power the MCU and the MCU LDO to power VMCU. The MCU LDO
is programmed nearest to the value of the external LDO: 1.5 V, 1.8 V, 2.5 V, or
3.3 V. The 2.0 μA MCU LDO current is consumed only while the TPS880x is
powered.
- Use an external LDO to power the MCU and a switch to connect the external LDO to
VMCU while the VCC switch is enabled.