FEATURES
n Works with DCM and BCM/CrCM Conduction Mode Flyback Topologies n VCC: 4.5V to 40V n Supports Up to 150V MOSFETs n 26ns Turn-Off Propagation Delay n Accurate Minimum On and Off Timers for Reliable Operation n Adjustable and Accurate Trip Point: +5mV to –30mV n 1Ω Gate Driver Pull-Down n SOT-23 5-Lead Package APPLICATIONS
n High Output Current Flybacks n High Efficiency Flybacks DESCRIPTION
The LT®8309 is a secondary-side synchronous rectifier driver that replaces the output rectifier diode in a flyback topology. By replacing the diode with a N-channel MOSFET, applications are no longer restricted by the heat constraints of the output diode. The IC replicates the behavior of a diode by sensing the drain-to-source voltage to determine when the current becomes negative. The 40V VCC rating allows the part to be driven from the output voltage or the rectified drain voltage of the MOSFET. A low quiescent current of 400µA maximizes efficiency at low output currents. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation.
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