ACF integration to a new level

     Silanna Semiconductor has expanded its line of CO2 smart power supplies for AC/DC and DC-DC converter technologies with the release of an ACF controller that integrates adaptive digital PWM control and UHV components. Includes 700V primary GaN FETs, X capacitor (X-CAP) discharge circuit, active clamp driver and start regulator.

     The company's CO2 smart power technology helps engineers simplify design and improve performance while managing environmental sustainability goals through more efficient energy use. Suitable for high efficiency and high power density power supplies, USB-PD/QC AC/DC power adapters and battery charging applications, the new SZ1200 integrated ACF controller combines the easy design of a simple inverse interference controller with all the benefits of ACF. These measures include recovering leakage energy from flyback transformers and limiting primary FET drain voltage spikes during shutdown events.

     With an efficiency of more than 93% at low voltages, the device provides consistent efficiency across a variety of load conditions in a common input voltage range (90-265VAC) and up to 150W for single - and multi-port USB-PD applications. The company's OptiMode digital control architecture adjusts the operating mode cycle by cycle to maintain high efficiency, low EMI, fast dynamic load regulation and other critical power parameters as line voltage and load change. For the most stringent USB-PD applications, low no-load power consumption minimizes energy consumption during system standby.

     "Our goal is to make it as easy as possible for power supply design engineers to develop ultra-efficient, high-density power conversion designs in the shortest time possible," said Ahsan Zaman, Director of product Marketing at Silanna Semiconductor. "The SZ1200 joins our family of ACF technologies to support this goal by providing high-speed switching, unprecedented integration and functionality that ensures optimal efficiency across a wide range of input and load conditions while minimizing EMI."

     By enabling designers to program the switching frequency to 250kHz, the new controller supports high power density, while advanced digital active clamp operation ensures best-in-class efficiency. Switching frequencies are limited to a tight band to simplify EMI filtering. Further efficiency and EMI performance benefits are achieved through adaptive digital control of active clamping operation, which allows the home effector to be turned on at near zero voltage and to clamp the drain voltage during a shutdown.

     The new device also includes CCM operation that delivers up to 225% of rated output power for a limited duration without sacrificing power density. This feature is targeted at applications that require peak power, such as laptops and laptop power adapters.