AN3011 Datasheet, PDF (1/37 Pages) STMicroelectronics – In certain applications such as LCD or plasma TVs

AN3011
Application note
Wide range input (90 - 265), single output (5 V-11 W)
EVLVIP27H-12SB, VIPer27 demonstration board
Introduction
In certain applications such as LCD or plasma TVs, desk top computers, etc., the power
supply that converts the energy from the mains often includes two modules: the main power
supply that provides most of the power which is off when the application is off or in standby
mode, and the auxiliary power supply that only provides energy to specific parts of the
equipment, like the USB ports, remote receivers, or modems, but stays on when the
application is in standby mode.
In standby mode it is often required that the equipment input power is as low as possible,
which means reducing the input power of the auxiliary power supply, in no-load or light-load
conditions, as low as possible. This demonstration board meets the specifications of a wide
range of auxiliary power supplies for the above mentioned applications. Furthermore, it is
optimized for very low standby consumption which helps to meet the most stringent energy
saving requirements. Using the VIPer27, which has a switching frequency of 115 kHz, helps
to reduce the transformer size.
Figure 1. Demonstration board image
January 2011
Doc ID 16043 Rev 1
!-V
1/37
www.st.com