AN2835 Datasheet, PDF (1/21 Pages) STMicroelectronics – This application note describes the electronic lamp ballast for 70 W high intensity discharge

AN2835
Application note
70 W HID lamp ballast
based on the L6569, L6385E and L6562A
Introduction
This application note describes the electronic lamp ballast for 70 W high intensity discharge
(HID) metal halide lamps (MHL) used for general indoor applications. The ballast is
composed of a boost converter and an inverter. The inverter is realized by a full bridge driver
with a power control circuit.
The booster converter for power factor correction (PFC) is controlled by the L6562A
controller (U1). The inverter is a full bridge topology driven by two pairs of half bridge buck
converters, L6385E (U3) and L6569 (U4), with the constant power control circuit L6562A
(U2).
In this note the dual-buck converter is introduced. One works in high frequency and the
other works in complementarity with necessary dead time at a lower frequency.
Figure 1. The demonstration board
May 2010
Doc ID 15073 Rev 1
!-V
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