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. Compared to discrete MOSFET and controller or self oscillating (RCC) switching converter solutions, a TOPSwitch integrated circuit can reduce total cost, component count, size, weight and at the same time increase efficiency and system reliability. These devices are intended for 100/110/230 VAC off-line Power Supply applications in the 0 to 100 W (0 to 50 W universal) range and 230/277 VAC off-line power factor correction (PFC) applications in the 0 to 150 W range.

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 700 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 design boards

? Integrated PWM Controller and 700 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