The L6574 is a high voltage driver chip suitable for lamp ballasts. It has high voltage and dV/dt immunity, providing 250mA driver current and 450mA sink current. The chip integrates features such as CMOS shutdown input, undervoltage lockout, preheat and frequency shifting timing, closed loop control, and protection.
The L6574 is a high‑voltage ballast driver designed for fluorescent lamp applications. It integrates a pre‑heat timing section, a voltage‑controlled oscillator, and a built‑in operational amplifier for closed‑loop lamp current control. The device can drive two power MOSFETs in a half‑bridge configuration and includes an integrated bootstrap circuit that eliminates the need for an external diode.
The handbook provides detailed pin descriptions, absolute maximum ratings, recommended operating conditions, electrical characteristics, timing diagrams, and mechanical dimensions. It also outlines protection features such as EN1/EN2 comparators and dV/dt immunity.
| Driver current capability | 250 mA source, 450 mA sink |
|---|---|
| High‑voltage rail | up to 600 V |
| Supply voltage range | 10 V to 600 V |
| dV/dt immunity | +50 V/ns |
It replaces an external bootstrap diode and provides the bootstrap voltage using a high‑voltage DMOS driver.