Integrated MOSFET interface for a synchronously-rectified SMPS

The availability of high-performance bipolar and MOSFET transistors upon the same substrate offers substantial advantages to the linear designer. NPN pulse power transistors combined with MOSFET predrive circuitry yield a high-performance gate driver that requires no DC bias current. Similarly, the availability of NPN transistors allows the use of translinear circuitry for analog computation. A SMPS control IC, incorporating gate drive and current limit circuitry that makes use of these advantages for a BiCMOS synchronously rectified buck switch-mode power supply, is described.