The document introduces a low-cost replacement for discrete switchers with 20 to 50 fewer components, reducing cost and increasing reliability. The product features source-connected tab and controlled MOSFET turn-on to reduce EMI and EMI filter costs. It allows for a 50% smaller and lighter solution and is cost competitive with linears above 5W. The product achieves up to 90% efficiency in flyback topology with built-in start-up and current limit to reduce DC losses. It also has a low capacitance 350V MOSFET to cut AC losses and a CMOS controller/gate driver that consumes only 6mW. The product simplifies design, reduces time to market, and is supported by many reference designs. It has an integrated PWM controller and 350V MOSFET in a industry standard three pin TO-220 package, requiring only one external capacitor for compensation, bypass, and start-up/auto-restart functions. The product also includes system-level fault protection features such as auto-restart and cycle by cycle current limiting functions, as well as on-chip latching thermal shutdown. It is highly versatile and can implement buck, boost, flyback, or forward topology, supporting continuous or discontinuous mode of operation. The product is specified for operation down to 16V DC input.
The TOP100‑4 TOPSwitch family provides a three‑pin solution for off‑line switched‑mode power supplies. It integrates a 350 V MOSFET, CMOS controller, 100 kHz oscillator and fault‑protection features in a TO‑220 package, reducing component count, cost and size while achieving up to 90 % efficiency in flyback topologies.
The handbook describes functional blocks, pin functions, typical application circuits, and performance specifications such as duty‑cycle limits, auto‑restart behavior, thermal shutdown and voltage regulation down to 16 V DC input. It also includes selection guides for output power ranges and example schematics for bias supplies, optocoupler feedback and power‑factor‑correction circuits.
| Integrated MOSFET voltage rating | 350 V |
|---|---|
| Controller power consumption | 6 mW |
| Maximum duty cycle | 70 % |
| Minimum input voltage | 16 V DC |
| Oscillator frequency | 100 kHz |
| Typical efficiency (flyback) | up to 90 % |
The TOP100‑4 can achieve up to 90 % efficiency in flyback topology.
It is specified for operation down to 16 V DC input.
The integrated oscillator runs at a nominal 100 kHz.
The controller and gate driver together consume only about 6 mW.