Active-clamp flyback PWM controllers enable high-efficiency supply designs

Silanna Semiconductor announced the launch of an expanded portfolio of Active Clamp Flyback Controllers (ACF). The SZ1110 and SZ1130 devices are active clamp flyback PWM controllers that integrate an adaptive digital PWM controller and the following Ultra High-Voltage (UHV) components: an active clamp FET, active clamp gate driver, and a startup regulator.  This unprecedented level of integration facilitates designing efficient, high-power-density adapters with low BoM cost to satisfy power-hungry mobile phones, tablets, notebooks and video game consoles.

Customers can see demonstrations of the ACF controllers, delivering over 94% efficiency with an all-silicon design and 27 W/in3 power density at 65 W for AC/DC power adapters together with the extensive DC/DC and AC/DC products at the demo room here.

The devices provide the ease-of-design of a simple flyback controller with all the benefits of an ACF design, including recycling of the leakage inductance energy of the flyback transformer and limiting the primary FET drain voltage spike during the turn-off events. Employing Silanna’s OptiModeTM digital control architecture, the SZ1110 and SZ1130 adjusts the device’s mode of operation 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.

SZ1110 and SZ1130-based AC/DC power supplies easily meet the stringent DoE and CoC efficiency and no-load standby power requirements.

Key Features:
•       Integrated UHV Active Clamp FET, Active Clamp Driver, and Start-up Regulator
•       Capable of Over 94% Efficiency
•       Flat Efficiency Across Universal (90 – 265 Vac) Input Voltage and Load
•       Up to 146 kHz Switching Frequency Operation
•       OptiMode™ Cycle-by-Cycle Adaptive Digital Control
•       Self-Tuning Valley Mode Switching (VMS)
•       Multi-Mode Operation (Burst Mode, QR, VMS)
•       > 6dB EMI Margin
•       OTP, OVP, OCP, OPP, and Output Short Circuit Protections
•       <50 mW No Load Power Consumption
•       Up to 65 W Output Power
•       16-pin SOIC Package

Applications
•       High Power Density AC/DC Power Supplies
•       High Efficiency Power Adapters
•       USB-PD/QC AC/DC Power Adapters
•       Battery Chargers for Mobile Devices