AN2300 Datasheet, PDF (1/21 Pages) STMicroelectronics – An alternative solution to Capacitive power

AN2300
Application Note
An alternative solution to Capacitive power
supply using Buck converter based on VIPer12A
Introduction
In this paper three different power supplies with two outputs are introduced: a Capacitive
passive network, and two versions of a low cost SMPS Buck converter. The last two are
based on VIPer12A, a high voltage Power MOSFET with a dedicated current mode PWM
controller, start-up circuit and protection integrated on the same silicon chip by
STMicroelectronics.
The considered converters are compared in terms of output voltage regulation, efficiency
and EMI, under the same output power conditions (about 0.6W).
Finally some modifications to the Buck converters are presented, in order to extend the
output power level to higher values, up to 1.1W.
The main specifications of the converters are listed in Table 1.
Table 1. Power supplies main specifications
AC input voltage V_IN
185÷265V_AC
Outputs
Total output power
V_out1=12V; I_out1=30mA
V_out2=5V; I_out2=40mA
0.6W
January 2006
Rev1
1/21
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