New Industry Products

Highly-Integrated Active Clamp Flyback Digital Controllers

April 13, 2020 by Paul Shepard

Silanna Semiconductor has launched an industry leading expanded portfolio of Active Clamp Flyback (ACF) controllers. The SZ1110 and SZ1130 devices are ACF pwm controllers that integrate an adaptive digital pwm controller and the following high-voltage components: Active Clamp FET, Active Clamp Gate Driver and a Startup Regulator.

This high 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.

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 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.

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- to 265-Vac) Input Voltage and Load
  • Up to 146kHz 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
  • <50mW No Load Power Consumption
  • Up to 65W Output Power
  • 16-pin SOIC Package

"Less than a year ago we launched the SZ1101, the world's first Active Clamp Flyback Controller, to an incredible customer and industry response," said Mark Drucker, CEO of Silanna Semiconductor. "This expansion into higher power and smaller form factors speaks to our core power density leadership. Silanna Semiconductor delivers ac-dc solutions with the highest power density and efficiency while simultaneously delivering the greatest value and reduced BoM costs."

"Unlike conventional ACF designs, tight tolerances of the clamp capacitor and leakage inductance values are not required for proper operation of the circuit in high volume production," said Ahsan Zaman, Director of Marketing. "The SZ1110 and SZ1130 are well-suited for high efficiency and high power density ac-dc power adapters. The devices are designed for up to 33W (SZ1110) and 65W (SZ1130) output power, including USB-PD and Quick Charge applications."