Description

   The TOPSwitch family implements, with only three pins, all functions necessary for an off-line switched mode control system: high voltage N-channel power MOSFET with controlled turn-on gate driver, voltage mode PWM controller with integrated 100 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

• 20 to 50 fewer components - cuts cost, increases reliability

• Source-connected tab and Controlled MOSFET turn-on

reduce EMI and EMI filter costs

• Allows for a 50% smaller and lighter solution

• Cost competitive with linears above 5 W

Up to 90% Efficiency in Flyback Topology

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

• Low capacitance 350 V MOSFET cuts AC losses

• CMOS controller/gate driver consumes only 6 mW

• 70% maximum duty cycle minimizes conduction losses

Simplifies Design - Reduces Time to Market

• Supported by many reference designs

• Integrated PWM Controller and 350 V MOSFET in a

   industry standard three pin TO-220 package

• 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