AN993 Datasheet, PDF (15/27 Pages) STMicroelectronics – Electronic ballast with PFC using L6574 and L6561

AN993
4
Description of the demonstration application
Description of the demonstration application
The design has been developed to drive a TL fluorescent lamp up to 58 W. It is composed of
two sections: the PFC, using the L6561 controller, and the ballast, based on the L6574 (see
Figure 13 and Figure 14). The application is provided with a current feedback that can be
used to control the power (and, if necessary, the dimming function) by varying the switching
frequency during normal burning of the lamp. The application is also provided with a safety
circuitry that gets activated when an open load or faulty ignition of the lamp is detected.
Figure 13. Demonstration application circuit
Doc ID 5656 Rev 10
AM01321v1
15/27