IR21571S Datasheet PDF - International Rectifier

●Description

●The IR21571 is a fully integrated, fully protected 600V ballast control IC designed to drive virtually all types of rapid start fluorescent lamp ballasts. Externally programmable features such as preheat time & frequency, ignition ramp characteris tics, and running mode operating frequency provide a high degree of flexibility for the ballast design engineer. Comprehensive protection features such as protection from failure of a lamp to strike, filament failures, low dc bus conditions, thermal

●overload, or lamp failure during normal operation, as well as an automatic restart function, have been included in the design. The heart of this control IC is a variable frequency oscillator with externally programmable deadtime. Precise control of a 50% duty cycle is accomplished using a T-flip-flop. The IR21571 is available in both 16 pin DIP and 16 pin narrow body SOIC packages.

●Features

●•Programmable preheat time & frequency

●•Programmable ignition ramp

●•Protection from failure-to-strike

●•Lamp filament sensing & protection

●•Protection from operation below resonance - 0.2V CS threshold sync’d to falling edge on LO

●•Protection from low-line condition

●•Automatic restart for lamp exchange

●•Thermal overload protection

●•Programmable deadtime

●•Integrated 600V level-shifting gate driver

●•Internal 15.6V zener clamp diode on VCC

●•Micropower startup (150uA)

●•Latch immunity protection on all leads

●•ESD protection on all leads