Fully integrated power management IC saves board space

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 analogue peripherals.

More than simply saving board space and BOM cost, compared to 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.

ST Authorised Partner Octavo Systems has utilised the STM32MP1 and STPMIC1 to create the OSD32MP1x family of microprocessor System-in-Package (SiP) devices, which occupy a footprint up to 64% smaller than an equivalent system implemented with discrete components while also addressing engineering challenges such as power sequencing.

Greg Sheridan, VP of Strategy at Octavo Systems commented: “The STPMIC1 is the perfect power-management solution for the OSD32MP1x family of system-in-package devices. With a single power input and 14 output rails including a 5V boost, it provides all the power needed for the STM32MP1 microprocessor while still providing plenty of options to power the rest of the system giving our SiP, which is packed in a tiny 18x18mm package, the flexibility to support a wide range of applications.”

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 with the STPMIC1. The board is easy to use, 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 5x6x0.8mm WFQFN 44-lead package, priced from $1.7 for orders of 1,000 pieces.