OB2301中文资料High Performance synchronous rectification controller数据手册OB规格书

描述 Description

OB2301 is a high performance and tightly integrated secondary side synchronous rectification controller and driver used for secondary side rectification in switch mode power supply system. It drivers 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. OB2301 can support low system output voltage down to 2V at constant current mode.
It is suitable for multiple mode applications including discontinuous conduction mode and quasi-resonant mode. With its versatility and optimization, OB2301 can be used in various switch mode power supply topologies including secondary-side control topology and primary-side control topology.
From the information on the secondary side of the isolation transformer, OB2301 generates a driving signal with dead time with respect to the primary side PWM signal to turn the integrated N-channel SR switch on and off in proximity of the zero current transition with the help of smart driver voltage control. It is optimized for 5V output voltage. In primary-side control topology, OB2301 can detect the output voltage and feed back a series of warning pulses to primary side controller when the output voltage is lower than an inner-determined threshold to awaken the primary-side power switch to improve dynamic response.
The externally adjustable minimum on time and property off time control scheme effectively avoid the ring impact induced by parasitic elements so that a reliable and noise free operation of the SR system is insured.
OB2301is ofered in SOT23-6 package.

特性 Features

• Secondary-side synchronous rectificationcontroller optimized for 5V output system
• Suitable for DCM,QR operation
• Accurate secondary side MOSFET Vds sensing
• Low cost small size CC/CV mode support Up to 200kHz operation frequency
• 3A/2A peak current sink/source driver capability
• Output voltage over-shoot and under-shoot control
• Enhanced dynamic response with firing warning pulses scheme
• VDD UVLO protection

应用 Application

• AC/DC 5V adaptors

• Cell phone charger

• 5V Bias supply

• Low voltage rectification circuits