Niveau: Supérieur, Doctorat, Bac+8
? Semiconductor Components Industries, LLC, 2004 April, 2004 ? Rev. 1 1 Publication Order Number: AN1080/D AN1080/D External-Sync Power Supply with Universal Input Voltage Range for Monitors Prepared by: S.K. Tong and K.T. Cheng ABSTRACT This paper describes the design of a low?cost 90 W flyback switching power supply for a multi?sync color monitor. In order to minimize the screen interference from the switching noise, the power supply can be automatically synchronized at the fixed frequency of the horizontal scanning frequency (15 to 32 kHz) of the color monitor. The line and load regulations of the power supply are excellent. Also, a new universal input?voltage adaptor enables the power supply to operate at two input voltage ranges, 90?130 Vac or 180?260 Vac. It can minimize the ripple current requirement of the input bulk capacitors and the stresses on the power switch. The design demonstrates how to use recently introduced components in a low?cost power supply. The state?of?the?art perforated emitter epi?collector bipolar power transistor MJE18004 and opto?isolator MOC8102 are utilized. 1. INTRODUCTION As the resolution of modern color display increases, the power supply for these high?definition monitors become critical in its features and performance. Nowadays, switching power supplies replace the linear regulators due to high efficiency and light weight. However, the EMI/RFI generated by switching power supplies has adverse effects on the resolution of high?definition color monitors (e.
- universal input?voltage
- dc isolation
- flyback converter
- into consideration
- output voltage
- discontinuous?mode flyback
- input filter
- constant current
- power supply