• Proprietary Operation Mode for Flyback ZVS
• Adaptive Gate Voltage Control
• DSEN Falling Slope Rate Detecting to Prevent SR False Triggering
• 130V DSEN Pin to Directly Sense DRAIN Voltage of SR MOSET
• Power Saving Mode to Improve Light Load Efficiency
• Dual Power Supply Channel for 3.3V to 21V Output Systems
• Compact Package: CPC8

The SQ33239 is a Flyback synchronous rectifier (SR) controller compatible with quasi-resonant (QR) mode converters, used to achieve zero voltage switching (ZVS) operation. The device is designed to complement primary side PWM converters operating in the QR mode.

Using a proprietary architecture, SQ33239 enables Flyback ZVS turn on, which can greatly improve the efficiency and increase the power density, while using adaptive gate voltage control to ensure system reliability.

The SQ33239 uses DRAIN sense (DSEN) voltage falling slope rate detection to avoid SR MOSFET false turn on caused by parasitic ringing in discontinuous conduction mode (DCM) or QR mode.

The SQ33239 is available in a CPC8 package.