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