The TNY277GN is an energy-efficient offline Switcher incorporates a 700V power MOSFET, oscillator, high voltage switched current source, current limit and thermal shutdown circuitry. It uses an ON/OFF control scheme and offers a design flexible solution with a low system cost and extended power capability. TinySwitch-III combines a high voltage power MOSFET switch with a power supply controller in one device. Unlike conventional PWM controllers, it uses a simple ON/OFF control to regulate the output voltage. The controller consists of an oscillator and enables circuit, current limit state machine, 5.85V regulator, BYPASS/MULTI-FUNCTION pin undervoltage, overvoltage circuit and current limit selection circuitry, over-temperature protection, current limit circuit, leading edge blanking. TinySwitch-III incorporates additional circuitry for line undervoltage sense, auto-restart, adaptive switching cycle on-time extension and frequency jitter.
Simple ON/OFF control, no loop compensation needed
Selectable current limit through BP/M capacitor value
Higher current limit extends peak power/in open frame, continuous power
Lower current limit improves efficiency in enclosed adapters/chargers
Allows optimum TinySwitch-III choice by swapping devices with no other circuit redesign
Maximizes MOSFET and magnetic power delivery
ON-time extension - Extends low line regulation range/hold-up time to reduce input bulk capacitance
Self-biased - No bias winding or bias components
Frequency jittering reduces EMI filter
Pin-out simplifies heat sinking to the PCB
SOURCE pins are electrically quiet for low EMI
Accurate hysteretic thermal shutdown protection with automatic recovery eliminates need for reset
Output overvoltage shutdown with optional Zener
Line undervoltage 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 field reliability
Easily meets all global energy efficiency regulations
No-load <150mW at 265VAC without bias winding, <50mW with bias winding
