Silanna takes ACF integration to next level
Combines PWM control, 700V GaN FET, X-Cap discharge, ACF driver and UHV start-up regulator in single chip
Silanna Semiconductor has expanded its CO2 Smart Power Family of AC/DC and DC/DC converter technologies with the launch of an active clamp flyback (ACF) controller that integrates adaptive digital PWM control with a 700 V primary GaN FET, X capacitor (X-Cap) discharge circuit, active clamp driver and start-up regulator.
Suited for high-efficiency and high-power-density power supplies, USB-PD/QC AC/DC power adapters and battery charging applications, the SZ1200 is said to combine the ease of design of a simple flyback controller with all the benefits of ACF. These include recycling of the leakage inductance energy of the flyback transformer and limiting primary FET drain voltage spikes during turn-off events.
Silanna says that the chip delivers above 93 percent efficiency at low line, and offers consistent efficiency across the universal input voltage range (90 - 265 Vac) and various loading conditions of up to 150W single-port and multi-port USB-PD applications. Silanna’s OptiMode digital control 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 as line voltage and load vary. Very low no-load power consumption for the most stringent USB-PD applications further minimizes energy use during system stand-by.
“Our goal is to make it as easy as possible for power design engineers to develop ultra-efficiency, high-density power conversion designs in the shortest time possible,” says Ahsan Zaman, Silanna Semiconductor’s, director of product marketing. “The addition of the SZ1200 to our family of ACF technologies supports this goal by offering high-speed switching, unprecedented levels of integration and functionality that ensures optimum efficiency across wide input and loading conditions while minimising EMI.”
SZ1200 also incorporates continuous conduction mode (CCM) operation, which allows delivering up to 225 percent rated output power for a limited duration without sacrificing the power density. This feature is targeted for applications requiring peak power, such as laptop and notebook power adapters.
