TNY 274-280 IC Chip

TNY 274-280(Energy Efficient, Off-Line Switcher with Enhanced Flexibility and Extended Power Range)

Introduction

TinySwitch-Ⅲ（TNY 274-280）incorporates a 700V power MOSFET,oscillator,high voltage switched current source, current limit (user selectable) and thermal shutdown circuitry. The IC family uses an ON/OFF control scheme and offers a design flexible solution with a low system cost and extended power capability.

Lowest System Cost with Enhanced Flexibility：

• Simple ON/OFF control, no loop compensation needed
• Selectable current limit through BP/M capacitor value
  – Higher current limit extends peak power or, in open frame applications, maximum continuous power
  – Lower current limit improves efficiency in enclosed adapters/chargers
  – Allows optimum TinySwitch-II choice by swapping devices with no other circuit redesign
• Tight I2f parameter tolerance reduces system cost
  – Maximizes MOSFET and magnetics power delivery
  – Minimizes max overload power, reducing cost of transformer, primary clamp & secondary components
• ON-time extension – extends low line regulation range/hold-up time to reduce input bulk capacitance
• Self-biased: no bias winding or bias components
• Pin-out simplifies heatsinking to the PCB
• SOURCE pins are electrically quiet for low EMI

Features

• Accurate hysteretic thermal shutdown protection with automatic recovery eliminates need for manual reset
• Improved auto-restart delivers <3% of maximum power in short circuit and open loop fault conditions
• Output overvoltage shutdown with optional Zener
• Line under-voltage detect threshold set using a single optional resistor
• Very low component count enhances reliability and enables single-sided printed circuit board layout
• High bandwidth provides fast turn on with no overshoot and excellent transient load response
• Extended creepage between DRAIN and all other pins improves feld reliability

Appearance