OB2011x is a high performance and tightly integrated secondary side synchronous rectifier for switch mode power supply system. It combines a much lower voltage drop N-channel MOSFET to emulate the traditional diode rectifier at the secondary side of Flyback converter, which can reduce heat dissipation, increases output current capability and efficiency and simplify thermal design.

It is suitable for multiple mode applications including discontinuous conduction mode (DCM) and quasi-resonant mode (QR) .The drain-to-source voltage of SR MOSFET is sensed to control the turn on and off of the SR MOSFET. In addition, to reduce SR falling time further, soft gate is implemented in OB2011x, which would pull down the gate voltage level before being turned off  thoroughly.

OB2011x is offered in CDFN8-7  package.


   Secondary-side synchronous rectifier

optimized for 5V output system

   Suitable for DCM, QR operation

   Soft gate drive for fast turn-off

   Accurate secondary side MOSFET Vds


   Vds slope detection effectively avoid the ring

impact induced by parasitic elements

   Low cost small size CV mode support

   Up to 200kHz operation frequency

   VDD UVLO protection


   AC/DC 5V adaptors

   Cell phone charger

   5V Bias supply

   Low voltage rectification circuits