Silanna launches Active Clamp Flyback reference design

1 min read

Silanna Semiconductor has launched an Active Clamp Flyback (ACF)-based reference design that will help to simplify and speed the development of 65W 1C fast charger applications.

Built around the company's SZ1131 ACF controller and incorporating Transphorm’s Super GaN FET, the RD-29 is a production-ready 65W 1C USB-PD reference design for travel adapters and battery chargers.

The reference design delivers peak efficiencies of 94.5% and flat efficiency across universal (90 – 265Vac) input voltages and loads. No-load power is just 23mW @ 230Vac and the design measures only 34.5mm x 34mm x 30.5mm, giving it an uncased power density of 30W/inch3.

“The RD-29 is a production-ready design that incorporates everything a designer needs to develop a charger and that already exceeds conducted and radiated EMI requirements by more than 6 dB,” said Ahsan Zaman, director of product marketing at Silanna Semiconductor. “Benchmarked against the best-in-class commercially available 65W charging products this reference design provides an impressive 1% higher efficiency and reduces vampire power by as much as 44%.

"Combined with the integration of our SZ1131 ACF controller, this has allowed us to create a solution that engineers can use to quickly develop compact and lightweight 65W chargers that operate with the least possible power consumption.”

Supplied in a 16-pin SOIC package, the SZ1131 ACF controller is the latest addition to Silanna's family of CO2 Smart Power technologies. These technologies simplify design and improve performance while addressing environmental sustainability goals through more efficient energy use.

The SZ1131 incorporates an adaptive digital PWM controller, ultra-high-voltage (UHV) active clamp FET, active clamp gate driver and start-up regulator and employs Silanna’s OptiMode digital control architecture.

This architecture adjusts operation mode on a cycle-by-cycle basis to maintain high efficiency, low EMI, fast dynamic load regulation, and other key power supply parameters in response to varying line voltage and load.

The SZ1131 incorporates protection against over-temperature, over-voltage, over-current, over-power, short circuit conditions and transformer core saturation faults without the need for additional external components.