TOP257LN

AC DC Converters, Offline Switchers Overview

The TOP257LN is an enhanced EcoSmart integrated off-line switcher from Power Integrations, incorporating a 700 V power MOSFET, high voltage switched current source, PWM control, oscillator, and startup circuit. It operates in flyback topology with switching frequencies of 66 kHz or 132 kHz. The device supports input voltages from 85 to 264 VAC, delivering up to 78 W at 85-264 VAC and 105 W at 230 VAC. It features a maximum duty cycle of 78%.

AC DC Converters, Offline Switchers Feature Summary

• Integrates a 700 V power MOSFET with high-voltage switched current source for cost-effective single-stage power conversion.
• Incorporates advanced feature set including programmable burst mode operation for low no-load power consumption.
• Provides complete protection against overvoltage, overcurrent, and overheating conditions.

AC DC Converters, Offline Switchers Applications

• Universal input offline AC/DC converters
• Battery chargers
• General purpose power supplies

AC DC Converters, Offline Switchers Procurement Notes

Verify the specific suffix 'LN' corresponds to the desired switching frequency option (66 kHz vs 132 kHz) as defined in the official datasheet. Confirm package type and pinout compatibility during integration. Ensure ordering documentation matches the manufacturer's part number format exactly to avoid substitution errors.

AC DC Converters, Offline Switchers Selection Notes

Select this component for applications requiring high efficiency and low standby power. The integrated design reduces external component count. Consider thermal management requirements given the power levels. Verify that the 700 V breakdown voltage meets the primary side stress requirements of the target transformer design.

AC DC Converters, Offline Switchers Part Context

This part belongs to the TopSwitch-HX family, which combines power switching and control functions into a single IC. The series is designed for high-reliability offline power supplies. It represents an evolution in integrated switcher technology aimed at reducing system complexity and cost while maintaining robust performance standards.

AC DC Converters, Offline Switchers Replacement Considerations

Check for direct substitutes within the TopSwitch-HX family such as TOP257EN or TOP257PN, ensuring pinout and electrical specifications match. Verify if alternative packages like DIP or eSIP are acceptable for the specific board layout constraints.