STMicroelectronics STPMIC1 Power Management IC is a fully integrated PMIC designed for products based on highly integrated application processor designs requiring low power and high efficiency. The STPMIC1 PMIC integrates advanced low-power features controlled by a host processor via I2C and IO interface. This PMIC integrates four synchronous step-down converters, which are optimised for high efficiency. To improve transient response, the converters use an adaptive constant on-time (COT) controller with a nominal switching frequency of 2MHz. The device also incorporates low dropout (LDO) regulators to supply power to the application processor as well as to the external system peripherals such as DDR memory, flash memory, and other system devices.