Integrated PMIC saves board space, cuts power consumption

By Gina Roos, editor-in-chief

STMicroelectronics has introduced the STPMIC1  power-management IC (PMIC), which integrates four DC/DC buck converters, a boost DC/DC converter, and six low-dropout regulators (LDOs), to meet the power demands in integrated application-processor−based systems. The chip is a companion PMIC for ST’s STM32MP1 heterogeneous multicore microprocessors that integrate single or dual Arm Cortex-A7 and Cortex-M4 cores, an optional 3D graphics processing unit, and digital and analog peripherals.

The four buck converters 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. The boost converter, with bypass-mode capability, can power up to two USB ports and ensures smooth regulation when operating from either a battery or 5-V AC/DC adapter.

Among the LDO channels, one is used 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.

The STPMIC1 also provides power-rail monitoring and protection, saving board space and bill-of-materials costs compared to using discrete components. It also handles power-up/-down sequencing and meets the ST32MP1 accuracy and settling-time specifications.

As an example, ST’s authorized partner Octavo System used the STM32MP1 and STPMIC1 to create the OSD32MP1x family of microprocessor system-in-package (SiP) devices, which is 64% smaller than an equivalent system implemented with discrete components while also addressing power sequencing.

Other features include a DDR memory reference voltage, a 500-mA USB OTG power switch, and a general-purpose power switch. An I² C interface and additional pins allow the MPU to manage the PMIC.

The STPMIC1 is in production now and available in a 5 × 6 × 0.8-mm WFQFN 44-lead package. The PMIC priced from $1.70 for orders of 1,000 pieces. An evaluation board, STEVAL-PMIC1K1, is available.