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