Description

This IC takes full advantage of IR’s patented ballast and high-voltage technologies to realize a simple, high-performance dimming ballast solution. A single high-voltage pin senses the half-bridge current and voltage to perform necessary ballast protection functions. The DC dim input voltage reference and the AC lamp current feedback have been coupled together allowing a single pin to be used for dimming. Combining these high-voltage control algorithms together with a simple dimming method in a single 8-pin IC results in a large reduction in component count, an increase in manufacturability and reliability, a reduced design cycle time, while maintaining high dimming ballast system performance

IC Features

? Dimming ballast control plus half-bridge driver

? Closed-loop lamp current dimming control

? Internal non-ZVS protection

? Internal crest factor protection

? Programmable preheat time

? Fixed dead-time (2.0μs typ.)

? Lamp insert auto-restart

? Internal bootstrap MOSFET

? Internal 15.6V zener clamp diode on Vcc

? Micropower startup (250μA)

? Latch immunity and ESD protection

Ballast System Features

? Single chip dimming solution

? Simple lamp current dimming control method

? Single lamp current sensing resistor required

? No half-bridge current-sensing resistor required

? No external protection circuits required (fully internal)

? Flash-free lamp start at all dimming levels

? Large reduction in component count

? Easy to use for fast design cycle time

? Increased manufacturability and reliability

Typical applications

? Linear dimming ballast (down to 10)

? 3-way dimming ballast

? Multi-level switch dimming ballast