Wed, 04/07/2004 - 11:03am
Semtech announces the SC4901, a secondary side synchronous regulator that can convert a transformer secondary voltage into multiple regulated DC outputs. The device is based on Combi-Sync technology, which enables this secondary side controller to combine synchronous rectification and synchronous post-regulation for isolated outputs. The product is a single-chip solution that eliminates the need for point-of-load regulators and primary side controllers in isolated power conversion applications such as voltage regulator modules, power converter bricks, and power supplies for telecommunications and networking applications. The regulator is self-biased from the transformer winding and also uses the transformer signal to create all of the timing functions necessary for regulation. No external bias synchronizing or drive signals are required. The device drives a back-to-back MOSFET combination that increases power conversion efficiency by eliminating the in-series rectifier diode that is the industry norm. This product can operate from a square wave input thus eliminating the need for a primary side regulator and the supporting circuitry across the isolation boundary. In addition, it can generate multiple regulated output voltages from a single transformer winding. The SC4901 device operates over an input voltage range of 4.5 to 18 V and can operate at speeds up to 1 MHz.