OB2011E Synchronous Rectifier Controller

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

Key Features

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• 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
• sensing
• 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

Applications

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• AC/DC 5V adaptors
• Cell phone charger
• 5V Bias supply
• Low voltage rectification circuits

Part Numbers and Specifications

Product family: On-Bright official page