Overview
The L6574, produced by STMicroelectronics, is a dedicated driver IC designed for controlling fluorescent lamps, particularly in CFL (Compact Fluorescent Lamp) and TL (Tubular Fluorescent Lamp) ballast applications. It is manufactured using BCD OFF LINE technology, enabling it to handle high voltage ratings up to 600V. The device is optimized for driving two power MOSFETs in a half-bridge topology, ensuring all necessary features for proper preheat, ignition, and control of the lamp.
The L6574 includes a dedicated timing section for setting preheat and ignition parameters, an integrated bootstrap section to eliminate the need for an external bootstrap diode, and an OP AMP for closed-loop control of the lamp current during normal operation.
Key Specifications
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| Supply Voltage (VS) | 10 | - | VCL | V |
| Supply Voltage Turn On Threshold (Vsuvp) | 9.5 | 10.2 | 10.9 | V |
| Supply Voltage Turn Off Threshold (Vsuvn) | 7.3 | 8 | 8.7 | V |
| Supply Voltage Clamping (Vcl) | 14.6 | 15.6 | 16.6 | V |
| Driver Current Capability (Source/Sink) | 250mA / 450mA | - | - | mA |
| Switching Times (Rise/Fall) | 80ns / 40ns | - | - | ns |
| dV/dt Immunity | ±50 V/ns | - | - | V/ns |
| Operating Temperature (Tamb) | -40 | - | 125 | °C |
| Storage Temperature (Tstg) | -40 | - | 150 | °C |
Key Features
- High Voltage Rail: Up to 600V, making it suitable for lamp ballast applications.
- Driver Current Capability: 250mA source and 450mA sink.
- Switching Times: 80ns rise and 40ns fall with a 1nF load.
- dV/dt Immunity: ±50 V/ns in the full temperature range.
- CMOS Shut Down Input: Allows for shutdown and restart of the device.
- Under Voltage Lock Out (UVLO): Protects the device from undervoltage conditions.
- Preheat and Frequency Shifting Timing: Dedicated timing section for setting preheat and ignition parameters.
- Integrated Bootstrap Diode: Eliminates the need for an external bootstrap diode.
- Clamping on Vs: Internal clamping at 15.6V typical.
- Sense OP AMP: For closed-loop control or protection features.
- High Accuracy Current Controlled Oscillator: For precise frequency control.
- SO16 and DIP16 Packages: Available in both narrow SO16 and DIP16 packages.
Applications
The L6574 is primarily designed for use in CFL (Compact Fluorescent Lamp) and TL (Tubular Fluorescent Lamp) ballast applications. It is well-suited for driving fluorescent bulbs in various lighting systems, including residential, commercial, and industrial lighting solutions.
Its features make it ideal for applications where high voltage handling, precise timing, and closed-loop control are necessary. This includes dimming and preheating functions, which are critical for efficient and reliable lamp operation.
Q & A
- What is the primary application of the L6574?
The L6574 is primarily used in CFL (Compact Fluorescent Lamp) and TL (Tubular Fluorescent Lamp) ballast applications.
- What is the maximum voltage rating of the L6574?
The L6574 can handle high voltage rails up to 600V.
- What are the driver current capabilities of the L6574?
The L6574 can source 250mA and sink 450mA of current.
- What is the switching time of the L6574 with a 1nF load?
The switching times are 80ns rise and 40ns fall with a 1nF load.
- Does the L6574 have built-in protection features?
Yes, it includes under voltage lock out (UVLO) and CMOS shut down input for protection.
- How does the L6574 handle preheat and ignition of the lamp?
The L6574 has a dedicated timing section that allows users to set the necessary parameters for proper preheat and ignition of the lamp.
- What is the role of the integrated OP AMP in the L6574?
The integrated OP AMP is used for closed-loop control of the lamp current during normal lamp burning and for protection features.
- What packages are available for the L6574?
The L6574 is available in SO16 and DIP16 packages.
- Does the L6574 have an integrated bootstrap diode?
Yes, the L6574 has an integrated bootstrap section that eliminates the need for an external bootstrap diode.
- What is the operating temperature range of the L6574?
The operating temperature range is from -40°C to 125°C.
- Is the L6574 RoHS compliant?
Yes, the L6574 is RoHS compliant with an Ecopack2 grade.
