HIGH PERFORMANCE SYNCHRONOUS RECTIFIER
DESCRIPTION
UTC USR5V10X 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 and quasi-resonant mode. With its versatility and optimization, UTC USR5V10X 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, UTC USR5V10X 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. It is optimized for 5V output voltage. In primary-side control topology, UTC USR5V10X 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 internally 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.
FEATURES
* Low cost small size CC/CV mode support
* Accurate secondary side MOSFET VDS sensing
* Secondary-side synchronous rectifier optimized for 5V output system
* Output voltage over-shoot control and under-shoot control
* Suitable for DCM, QR operation
* Up to 150kHz operation frequency
* VDD UVLO protection
Singapore
