The STSW-USBPD27SFW software package contains the application source code designed to demonstrate the capabilities of the STEVAL-USBPD27S 27 W AC-DC USB-C and Power Delivery adapter with PPS functionality.
The application firmware is designed to run on the mainstream ARM®
-M0+ 32-bit STM32G071RB microcontroller integrated in the STEVAL-USBPD27S and embeds the USB-PD 3.0 middleware stack coming from the STM32CubeG0 firmware package, making the solution compliant with the USB Type-C v.1.3 and Power Delivery v.3.0 specifications.
The STSW-USBPD27SFW embeds three proprietary software IPs (as compiled libraries) that allow the STM32G071RB microcontroller to manage the synchronous rectification (SR) mechanism and to operate on the output voltage/current to cope with the Programmable Power Supply feature. Thus, the microcontroller acts as synchronous rectification manager and USB Power Delivery controller, maximizing the power conversion efficiency and reducing the system-level power consumption and the BOM components. These requirements, together with the microcontroller low power mode, allow a low standby power consumption in line with the energy efficiency regulation (CoC Tier 2 and DoE Level VI).
The application firmware enables the adapter to deliver two fixed PDOs (5 V at 5 A, 9 V at 3 A), properly managing the constant voltage (CV) mechanism, and two APDOs (5 V Prog at 5 A and 9 V Prog at 3 A), adjusting the output voltage with 20 mV steps in CV mode and the output current with 50 mA steps in constant current (CC) mode.