This paper introduces a new high voltage IC driver L6569 for electronic lamp ballasts. The driver features a simple, monolithic oscillator-half bridge driver, which allows quick design of the ballast. The paper also discusses the applications and characteristics of electronic lamp ballasts.
The document introduces the L6569, a monolithic oscillator-half bridge driver developed by STMicroelectronics to drive floating transistors in symmetric half-bridge inverters. It is designed for electronic lamp ballasts used in Compact Fluorescent Lamps (CFLs), halogen transformers, and tube lamps, offering features like cost reduction and energy saving through dimming.
The note details the internal architecture of the L6569, including its 270mA buffers with a built-in 1.25 µs dead time and a high-voltage level shifter. It provides guidance on circuit design considerations such as component selection for MOSFETs, auxiliary supply generation using snubbers or secondary windings, and various shutdown methods to ensure robust operation.
| Buffer Current | 270mA |
|---|---|
| Built-in Dead Time | 1.25 µs |
| Level Shifter Voltage | 600V |
| Oscillator Frequency Range | 25 to 150 kHz |
| Internal Regulator Voltage | 15V |
| Power Up Current | 150 µA |
The primary application is the Compact Fluorescent Lamp, but it can also be used for low voltage halogen lamp transformers and industrial TL ballasts.
It uses two 270mA buffers that drive the inverter MOSFETs in complementary fashion with a built-in dead time.
In new design, this frequency should be set between 50 and 100 kHz.