Fully integrated power-management IC

With features including four DC/DC buck converters, a boost DC/DC converter, and six low-dropout regulators (LDOs), the STPMIC1 power-management IC (PMIC), from STMicroelectronics, looks to address the complex power demands of highly integrated application-processor based systems.

The chip is optimised as a companion PMIC for ST’s STM32MP1 heterogeneous multicore microprocessors, which target a broad range of applications by integrating single or dual Arm Cortex-A7 and Cortex-M4 cores, an optional 3D graphics processing unit, and rich digital and analog peripherals.

The device not only saves board space and reduces BOM cost by arranging the same number of power rails using discrete components, the STPMIC1 also provides power-rail monitoring and protection, handles power-up/down sequencing, and meets the ST32MP1 accuracy and settling-time specifications.

In addition to supplying power rails for the microprocessor unit (MPU) and external system components, the STPMIC1 also provides a DDR memory reference voltage, a 500mA USB OTG power switch, and a general-purpose power switch. An I2C interface and additional pins allow the MPU to manage the PMIC.

The four buck converters in the PMIC are designed for fast transient response and precise output-voltage control to handle a wide range of operating conditions. A pulse-frequency modulation mode boosts energy efficiency at low loads. During normal operation, pulse-width modulation (PWM) synchronisation minimises electro-magnetic interference (EMI). The boost converter, with bypass-mode capability, can power up to two USB ports and ensures smooth regulation either when operating from a battery or low-cost 5V AC/DC adapter.

Among the six LDO channels, one is featured for DDR3 termination and can operate in bypass mode for low-power DDR, while another provides automatic source detection to power a USB PHY. The remaining four LDOs are general-purpose outputs.

An evaluation board, STEVAL-PMIC1K1, is also available, which simplifies prototyping. Easy to use, it comes with with pushbuttons and digital I/Os for triggering the PMIC features and header connectors for accessing the regulators and switches. A USB dongle is also included for configuring the device registers.

The STPMIC1 is in production now and available in a 5mm x 6mm x 0.8mm WFQFN 44-lead package.