Article by: STMicroelectronics
STMicroelectronics’ new chip, ST-ONE, will increase energy efficiency in a wide variety of AC/DC adapters.
STMicroelectronics improves the sustainability of personal computing with its latest innovation: a new chip called ST-ONE, which will increase power efficiency in a wide range of AC/DC adapters, fully compatible with USB-PD 3.1, including chargers for laptops and smart phones. New adapters built with ST-ONE can reduce both the CO2 emissions and the amount of plastic used.
The new ST-ONE chip is mated to ST’s MasterGaN power modules based on advanced gallium nitride (GaN) semiconductor technology. The GaN chips enable significant energy savings and smaller equipment sizes.
While laptops offer optional power-saving settings, any machine can save even more power if it’s equipped with a more efficient power adapter. This improves the environmental profile and CO2 footprint. The ST-ONE chip is optimized for controlling power supplies that recover energy normally dissipated as heat from conventional circuits. It also simplifies circuit design with a significant reduction in the number of components, making this type of power supply more robust, affordable and widely adopted in the market.
“If each power adapter achieved at least a 1% increase in efficiency, which is possible with the design of the ST-ONE power recovery circuit, the world could save approximately 93 terawatt hours of energy, equivalent to the output of 15 nuclear power plants. said the comment. Domenico Arrigo, General Manager, Industrial and Power Conversion Division, STMicroelectronics. “In addition, if a billion chargers worldwide were to use our technology, 0.2 million tons of plastic and raw materials could be saved.”
The reduction in the consumption of materials such as plastics is achieved through the increase in the so-called power density, which allows smaller components to manage a greater power delivery. High power density also lowers recycling and environmental costs.
On display at the Embedded World exhibition in Nuremberg, Germany, ST’s reference design, EVLONE65W, turns a 65W USB-C adapter of the same size and weight (less than 70g in a 37cm3) from a standard 20-inch Watt smartphone charger can handle the demands of charging a laptop. This unit achieves the world’s highest power density, with power exceeding 1.8 watts per cubic centimeter.
ST-ONE is optimized for designs based on a new non-complementary active-clamp flyback topology, which allows high power above 65W, with higher efficiency than other topologies such as the quasi-resonant flyback.
It is the world’s first digital controller to integrate a programmable offline power controller based on Arm® Cortex®-M0+ core, a high voltage starting circuit, a synchronous rectification controller and USB Power Delivery (USB-PD) circuitry in one package.
The ST-ONE contains all the peripherals needed to control the conversion. USB-PD communication is implemented on the secondary side and reinforced galvanic isolation is provided to allow the primary and secondary circuits to communicate in compliance with safety requirements.
Also, by utilizing the MasterGaN integrated power stage with advanced wide-bandgap transistors and optimized drivers, adapters operate at increased switching frequencies, enabling smaller magnetic components to maximize power density.
The ST-ONE comes with 64KB built-in flash to allow designers to customize both the USB-PD protocol and the power conversion stage.
The ST-ONE controller comes with USB-PD 3.1 PPS certified firmware preloaded in the flash memory, providing users with a turnkey solution for designing standard applications.