ST-ONEMP digital controller supports two-port USB-PD adapters
The latest member of STMicroelectronics’ power-saving ST-ONE family of USB power delivery (USB-PD) digital controllers is the ST-ONEMP, which supports two power outputs.
The ST-ONEMP uses the ST-ONE architecture combining an Arm Cortex-M0+ microcontroller, energy-efficient non-complementary active clamp flyback controller, and USB-PD 3.1 interface in a single package. Galvanic isolation between primary-side and secondary-side circuitry allows the ST-ONE architecture to simplify the design and assembly of USB-PD power adapters, said ST. Now, adding support for power sharing, means that the ST-ONEMP simplifies implementing a second output in addition to the USB-PD output.
The Cortex-M0+ microcontroller is embedded on the secondary side and has 64kbyte of flash for customising the USB-PD protocol and power conversion firmware. USB-PD 3.1 PPS certified firmware is pre-loaded. The microcontroller controls the synchronous rectifier and the flyback converter and is optimised for zero-voltage switching non-complementary active-clamp topology, which allows high power with greater efficiency than conventional quasi-resonant flyback, said ST.
The ST-ONEMP pairs with ST’s MasterGaN power technology, which contains ST’s gallium nitride (GaN) wide-bandgap power transistors with integrated gate drivers. GaN technology permits superior switching at higher frequencies than conventional silicon MOSFETs, enabling adapters to deliver greater power density with high energy efficiency meeting the latest ecodesign codes.
ST has produced the EVLONEMP reference design leveraging ST-ONEMP and MASTERGAN4 to create a 65W + 10W AC/DC adapter at comparable weight and volume to a 20W single-port smartphone charger. Peak efficiency, at 94 per cent, is two per cent higher than comparable conventional two-port adapters, while the PCB area is a quarter of the size, reported ST.
The ST-ONEMP is available now in a SSOP36 package.
