For your reference, this PMIC includes a list of SOT-143 functions. Using Surface Mount, IC management is mounted. There are 4 pins on the supervisor. Normally, the supply voltage (Vsup) for this PMIC should not be lower than 1V. The maximum supply voltage (Vsup) in this PMIC should not exceed 5.5V volts. It also contains ICs of other kinds, such as POWER SUPPLY SUPPORT CIRCUIT, which are included in the power management.
MAX6421US17+ Features
Minimum supply voltage of 1V
MAX6421US17+ Applications
There are a lot of Maxim Integrated MAX6421US17+ Voltage Supervisors applications.