L6574

Lighting, Ballast Controllers Overview

The L6574 is a CFL/TL ballast driver manufactured using BCD OFF LINE technology, enabling voltage ratings exceeding 600V. It drives two power MOSFETs in a half-bridge topology for fluorescent lamp control. Key electrical parameters include a high-voltage rail up to 600V, driver current capability of 250mA source and 450mA sink, switching times of 80ns rise and 40ns fall, and dV/dt immunity of ±50 V/ns with a 1nF load. The device integrates an accurate current-controlled oscillator, a sense operational amplifier for closed-loop control, and a bootstrap section.

Lighting, Ballast Controllers Feature Summary

• Integrated bootstrap section eliminates the need for external bootstrap diodes and Zener clamping on Vs.
• Dedicated timing section allows user-defined preheat and ignition parameters for proper lamp startup.
• Sense operational amplifier supports closed-loop control or protection features during normal operation.
• High dV/dt immunity ensures stable performance across the full temperature range.

Lighting, Ballast Controllers Applications

• Cold cathode fluorescent lamp (CCFL) backlighting for LCD TVs
• PC monitor backlighting inverters
• CFL and TL ballast driver circuits

Lighting, Ballast Controllers Procurement Notes

Verify the specific package variant (SO16 or DIP16) required for your design. Confirm that the application utilizes a half-bridge topology compatible with the L6574's dual MOSFET drive capability. Ensure input voltages and lamp requirements align with the device's 600V rating and current specifications before finalizing procurement.

Lighting, Ballast Controllers Selection Notes

Select the L6574 when designing cost-effective, high-performance ballasts requiring integrated bootstrap functionality to reduce component count. It is suitable for applications needing precise preheat timing and closed-loop current control via the internal op amp. Consider this part for systems where high-voltage isolation and robust dV/dt immunity are critical for reliability.

Lighting, Ballast Controllers Part Context

The L6574 is part of STMicroelectronics' offline ballast driver family, leveraging BCD technology for high-voltage integration. It addresses efficiency improvements in AC-DC power supplies and inverters by reducing conduction losses in primary switches and bridge rectifiers. The device simplifies design by integrating timing, driving, and control functions into a single IC.

Lighting, Ballast Controllers Replacement Considerations

No public confirmed substitute part numbers are available in the provided documentation. Designers should consult official STMicroelectronics resources for potential alternatives or newer generations of ballast drivers.

Lighting, Ballast Controllers FAQ

What is the purpose of the integrated bootstrap section in the L6574?

The integrated bootstrap section eliminates the need for an external bootstrap diode and Zener clamping on the Vs pin, reducing the number of additional components required for high-performance ballast designs.

How does the L6574 handle lamp preheating?

A dedicated timing section within the L6574 allows users to set necessary parameters for proper preheat and ignition of the lamp, ensuring optimal startup conditions.

What is the dV/dt immunity specification of the L6574?

The L6574 offers dV/dt immunity of ±50 V/ns in the full temperature range with a 1nF load, ensuring reliable operation under high-speed switching conditions.