OB2014

GENERAL DESCRIPTION

OB2014x 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 can support wide range of system output voltage 3V~12V.

It is suitable for multiple mode applications including discontinuous conduction mode (DCM), quasi-resonant mode (QR) and continuous conduction mode (CCM). Especially for CCM, to guarantee system reliability, super fast SR turn-off comparator and soft gate driver are used to reduce the whole propagation delay in SR turn-off control path.

To avoid the ring impact induced by parasitic elements, the innovative property ring detection is implemented on chip to prevent SR turn on falsely so that a reliable and noise free operation of the SR system is insured.

In addition，the Vds voltage is regulated to about -30mV through on-chip soft gate driver control regardless of Rdson of SR MOSFET to achieve more reliable operation.

OB2014x is offered in SOP8 package.

FEATURES

■   Secondary-side synchronous rectifier for 3V~12V output system

■   Suitable for DCM, QR and CCM operation

■   Internal Power MOSFET

■   Accurate secondary side MOSFET Vds sensing

■   Innovative property ring detection to avoid the ring impact induced by parasitic elements

■   Soft gate driver

■   VDD UVLO protection

APPLICATIONS

■   AC/DC 3V~12V chargers/adaptors

■   Low voltage rectification circuits

   

TYPICAL APPLICATION 

Flyback high side synchronous rectification

 

Flyback low side synchronous rectification