Existar EX9506

Ex9506 is a synchronous rectification switch with an integrated 60V breakdown voltage power transistor featuring 10mΩ low on-resistance. Designed for the secondary side of AC/DC flyback switching power supply transformers as a replacement for output rectifier diodes, it significantly improves switching power supply conversion efficiency. The integrated high-voltage self-powering function eliminates the need for a transformer auxiliary winding supply — only a single 1uF capacitor is required for chip power supply, with a self-supply voltage of 7.7V. It can be flexibly placed at either the positive or negative output terminal of the transformer. The Ex9506 controls the turn-on and turn-off of the built-in MOSFET by detecting the VDS voltage. When the VDS voltage drops below -350mV, the MOSFET is turned on; with integrated dynamic MOSFET driving, the VDS voltage is regulated to approximately -40mV. When the VDS voltage rises above 0mV, the MOSFET is turned off. The built-in power transistor uses an SGT MOSFET with lower gate capacitance, enabling faster turn-off, effectively reducing voltage spikes, thereby lowering voltage stress and improving reliability. An integrated resonant ringing voltage slew rate detection function prevents false turn-on due to resonance. Compatible with high-frequency applications where the primary-side PWM uses GaN power transistors. The synchronous rectification switch features fast turn-off capability and supports DCM discontinuous conduction mode, QR quasi-resonant operation, and CCM continuous conduction mode.

• AC/DC switching power supply USB PD adapters, chargers