System description

The device has the following core components that are described in detail in their respective chapters.

The system regulator (SYSREG) is supplied by VBUS. It supports 4.0 V to 5.5 V for internal functions and tolerates transient voltages up to 22 V. Overvoltage protection is implemented for both internal and external circuitry. SYSREG also implements current limiting for VBUS to comply with the USB Type-C specification. SYSREG supports Type-C charger detection.

The battery charger (CHARGER) is a JEITA compliant linear battery charger for lithium-ion (Li-ion), lithium-polymer (Li-poly), and lithium iron phosphate (LiFePO₄) batteries. CHARGER controls the charge cycle using a standard Li-ion charge profile. CHARGER implements dynamic power-path management regulating current in and out of the battery, depending on system requirements, to ensure immediate system operation from VBUS if the battery is depleted. Safety features, such as battery temperature monitoring and charger thermal regulation are supported.

Two independent, highly efficient buck regulators (BUCK) supply the application circuitry and offer several output voltage options. BUCK is controlled through registers or GPIO pins. Default output voltage can be set with external resistors.

The two load switches (LOADSW/LDO) can function as switches or linear voltage regulators to complement the power distribution network. LOADSW/LDO is controlled through registers or GPIO pins.

The System Monitor provides measurements for battery voltage, battery current, VBUS, battery, and die temperature.

The device also features Ship and Hibernate modes, the lowest quiescent current states. They disconnect the battery from the system and reduce the quiescent current of the device to extend battery life. Hibernate mode can be utilized during normal operation as the device can autonomously wake-up after a preconfigured timeout. This makes it possible to extend battery life to the maximum capacity.