AN3256 Datasheet, PDF (1/23 Pages) STMicroelectronics – Low-cost LED driver for an A19 lamp

AN3256
Application note
Low-cost LED driver for an A19 lamp
Introduction
This application note describes a prototype of a non-dimmable, non-isolated LED driver.
The physical design is small enough to fit in the base of an A19 (screw bases 40 to 60 W
equivalent) bulb outline. The coupled inductor has a stepdown winding to power the L6562A
PFC driver.
The design goals:
■ Input: 96-132VAC, 60 Hz, non-dimmable, TRIAC dimmer safe (no damage)
■ Output: 370 mA into strings of 5 to 12 LEDs
■ Topology: stepdown (buck) switching regulator
■ Features: regulation of LED current, power factor acceptable for US market for residential
use, excellent efficiency
ST devices:
■ PFC controller: L6562A
■ Switching FET: STD5NM50
■ Flywheel diode: STTH1R04
Figure 1. Physical envelope
Figure 2. Image
September 2010
Doc ID 17790 Rev 1
1/23
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