SC4901 Datasheet | SEMTECH

Description BI-SYNC Secondary Side Synchronous Rectifier and Regulator Features ‹ Single controller performs synchronous rectification ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ and post regulation Independent regulation of multiple outputs from a mon secondary winding Turn on shoot through inherently eliminated Primary switch turns ON and OFF with zero current No synchronising or any other signals needed across the isolation boundary Eliminates the need for a secondary bias supply Independent soft start, ON/OFF, remote sense and current limit for each output Resistive or inductive current sensing with 2V current signal and 2.5V reference for external applications. 4.5 to 18V operation Max operating frequency to 1 MHz Low profile 16 pin TSSOP package Based on Semtech’s patented bi Sync concept SC4901 is a unique secondary side regulator designed for implementing Semtech’s proprietary bi-Sync topology for isolated convertors with multiple outputs. The bi-Sync is a true all-MOSFET topology that allows synchronous rectification and post regulation of transformer isolated outputs, resulting in higher efficiency and low ponent count. Details of this unique topology are described in the Application Information section. .. Multiple outputs can be synchronously rectified and independently regulated by individual SC4901s. Each output has its own ON/OFF control, soft start, remote sense and current limits. They can be turned on or off without affecting the primary or other outputs. The secondary side control makes it much easier to design tight control loops and implement load current sharing and hot swap Features . All devices are synchronised to the transformer winding. The current sense can be either from the output inductor for high efficiency or a resistor for better accuracy. An amplified current signal is provided for external use. Each device is capable of driving high side MOSFETs with 2A current. The forward drive is configured for direct connection to a 1:1 pulse...