TOP256PN Integrated Off-Line Switcher IC PDIP-8C
TOP256PN belongs to the TOPSwitch-HX family, a monolithic off-line switcher that combines a high-voltage power MOSFET with control and protection circuitry in one device. The datasheet presents it as a compact way to build efficient flyback power supplies while reducing external parts and overall system cost.
It is designed to keep the supply stable across operating conditions by using integrated control functions such as PWM regulation, soft-start, fault handling, and thermal shutdown. The family also supports multi-mode operation, which helps maintain efficient performance from light load to full load.
In the PDIP-8C package, TOP256PN is suited to compact offline converter designs where predictable behavior, low standby consumption, and strong protection features matter. The datasheet shows it as a flexible part for universal-input and other power-supply implementations.
Features:
- Integrates a 700 V power MOSFET with PWM control, oscillator, thermal shutdown, and fault protection on one monolithic chip.
- Uses multi-mode control to improve efficiency across the load range.
- Includes a fully integrated 17 ms soft-start to reduce start-up stress and overshoot.
- Provides auto-restart and hysteretic thermal shutdown for automatic recovery from fault and overtemperature conditions.
- Supports line undervoltage, line overvoltage, output overvoltage protection, and line feed-forward functions through its control pins.
- Offers switching-frequency jitter to help reduce EMI.
- Allows external current-limit adjustment for added design flexibility.
Specifications:
| Specification | TOP256PN value |
|---|---|
| Family: | TOPSwitch-HX |
| Package: | PDIP-8C |
| Package identifier: | P = Plastic DIP-8C |
| Pin finish: | N = RoHS compliant and halogen free |
| Switching frequency: | 66 kHz (P/G/M packages) |
| Output power at 230 VAC ±15%: | 21 W adapter, 34 W open frame, 63 W peak |
| Output power at 85–265 VAC: | 15 W adapter, 26 W open frame, 40 W peak |
| DRAIN supply voltage: | 18 V to 36 V |
| Breakdown voltage: | 700 V |
| Rise time: | 100 ns |
| Fall time: | 50 ns |
| Self protection current limit: | 1.255 A min, 1.35 A typ, 1.445 A max |
| Soft-start time: | 17 ms |
| Thermal shutdown temperature: | 142 °C typ |
| Thermal shutdown hysteresis: | 75 °C |
Pinout:
- MULTI-FUNCTION (M) Pin
- DRAIN (D) Pin
- CONTROL (C) Pin
Applications:
- A High Efficiency, 35 W, Dual Output – Universal Input Power Supply.
- A High Efficiency, 150 W, 250-380 VDC Input Power Supply.
- A High Efficiency, 20 W Continuous – 80 W Peak, Universal Input Power Supply.
- A High Efficiency, 65 W, Universal Input Power Supply.
Package Contents:
- 1x TOP256PN Integrated Off-Line Switcher IC PDIP-8C