Unveiling our family expansion of Flyback PWM Controllers with Integrated Active Clamp Circuits

Silanna Semiconductor focuses on the ultimate Power Management challenges with best-in-class power density and efficiency performance that delights customers with unprecedented BOM savings. First announced at APEC 2019, Silanna Semiconductor has delivered on the customer expectations and market penetration of Active Clamp Flyback Controllers, and now dominates the integrated ACF market.

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

    The device provides 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 Semiconductor’s OptiMode™ 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.

    Key Features:

    • Integrated UHV Active Clamp FET, Active Clamp Driver, and Start-up Regulator

    • Capable of over 94.5% 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 65W output power

    • Capable of over 27W/in  power density 

    • 16-pin SOIC package

    • Meets DoE and CoC efficiency and no-load standby power requirements


    • High Power Density AC/DC Power Supplies

    • High Efficiency Power Adapters 

    • USB-PD/QC AC/DC Power Adapters 

    • Battery Chargers for Mobile Devices


    Operation demo of SZ1130 active clamp flyback controller at 20V.

    Press Contact

    Lexi Hatzi