AN3407 Datasheet, PDF (1/25 Pages) STMicroelectronics – Resonant driver for LED SMPS demonstration board

AN3407
Application note
Resonant driver for LED SMPS demonstration board
based on the L6585DE
Introduction
This application note describes the performance of a 100 W LED switched-mode power
supply (SMPS). The L6585DE embeds a high-performance transition mode (TM) power
factor correction (PFC) controller, half-bridge (HB) controller and all the relevant drivers
necessary to build a combo IC. The L6585DE embeds a wide range of features to provide
an energy-saving and cost-effective solution for the LED SMPS demonstration board
(STEVAL-ILL038V1).
Previous dedicated ICs for LED SMPS applications allowed designers to achieve good
driver efficiency. The PFC section has superior performance in terms of harmonic content
mitigation. High power factor (PF) and total harmonic distortion (THD) reduction are
obtained as required by international norms, especially concerning universal input voltage
operations. The TM PFC operation and high-efficiency performance of the half-bridge
topology provide very good overall circuit efficiency.
Film capacitors are one of the most popular types of discrete components. They generally
offer excellent electrical properties and are advantageous in high current and high
temperature conditions. For these reasons, film capacitors are used in LED SMPS
applications. In order to guarantee maintenance-free operation required by these types of
applications during the useful lifetime of the LED, electrolytic capacitors have been replaced
by film capacitors in the STEVAL-ILL038V1 board.
Other features, such as half-bridge overcurrent with frequency increase and PFC
overvoltage, allow designers to build a reliable, flexible solution with a reduced component
count.
Figure 1. STEVAL-ILL038V1 demonstration board
August 2011
Doc ID 018857 Rev 1
1/25
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