Description

The TOPSwitchfamily implements, with only three terminals, all functions necessary for a DC to DC, converter: high voltage N-channel power MOSFET with controlled turn-on gate driver, voltage mode PWM controller with integrated 120 kHz oscillator, high voltage start-up bias circuit, bandgap derived reference, bias shunt regulator/error amplifier for loop compensation and fault protection circuitry.

Product Highlights

Low Cost Replacement for Discrete Switchers

? Up to 15 fewer components - cuts cost, increases reliability

? Allows for a smaller and lighter solution under 12 mm height, all surface mount components

Over 80 Efficiency in Flyback Topology

? Built-in start-up and current limit reduce DC losses

? Low capacitance MOSFET cuts switching losses

? CMOS controller/gate driver consumes only 7 mW

? 70 maximum duty cycle minimizes conduction losses

Simplifies Design - Reduces Time to Market

? Integrated PWM Controller and high power MOSFET

? Only one external capacitor needed for compensation, bypass and start-up/auto-restart functions

System Level Fault Protection Features

? Auto-restart and cycle by cycle current limiting functions handle both primary and secondary faults

? On-chip latching thermal shutdown protects the entire system against overload

Highly Versatile

? Implements Buck, Boost, Flyback or Forward topology

? Easily interfaces with both opto and primary feedback

? Supports continuous or discontinuous mode of operation

? Specified for operation down to 16 V DC input