AN2600 Datasheet, PDF (1/30 Pages) STMicroelectronics – SMPS for high-end PVR based on L6668

AN2600
Application note
SMPS for high-end PVR based on L6668
Introduction
The set-top box (STB) market is growing very fast due to the high growth of both satellite
and terrestrial/cable broadcasting. As expected, the market is always looking for solutions
with high cost effectiveness and performance.
This document introduces a reference design of a 55 W switch-mode power supply
dedicated to high-end set-top box applications, and in particular for PVRs (Personal Video
Recorders). This kind of solution in addition to typical loads is able to supply HD and VFD
front panels. The board accepts European input voltage range (from 185 to 265V_ac) and
delivers eight outputs. It is based on the advanced current mode PWM controller L6668,
working at fixed frequency. Despite high performance, standard parts are used, e.g.
standard capacitors are connected on the outputs in place of low ESR components
commonly used, contributing to an overall decrease of the total cost of the solution.
Figure 1. STEVAL-ISA040V1
January 2008
Rev 1
1/30
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