EVLB001 Datasheet, PDF (5/35 Pages) ATMEL Corporation – Automatic microcontroller dimmable ballast

Introduction
1.1 General
Description
Fluorescent ballast topology usually includes line conditioning for CE and UL compli-
ance, a power factor correction block including a boost converter to 400 V for universal
input applications and a half bridge inverter. By varying the frequency of the inverter, the
controller will preheat the filaments (high frequency), then ignite the lamp (reducing the
frequency). Once the lamp is lit, varying the frequency will dim the light. The Atmel
AT90PWM2B/216 microcontroller can be programmed to perform all of these functions.
Figure 1-2. Ballast Demonstrator Board
1.2 Ballast
Demonstrator
Features
• Automatic microcontroller dimmable ballast
• Universal input – 90 to 265 VAC 50/60 Hz, 90 to 370 VDC
• Power Factor Corrected (PFC) boost regulator
• Power feedback for stable operation over line voltage range
• Variable frequency half bridge inverter
• 18W, up to 2 type T8 lamps
• Automatic dimmable single lamp operation
• Automatic detection of Swiss or DALI
• Very versatile power saving options with microcontroller design for most functions
1-3
7597B–AVR–10/07
ATAVRFBKIT / EVLB001 User Guide