Reduction Method of Voltage Fluctuation of DC Power Supply in Digital IC

Tadaharu AKINO  Yasuhiro ONO  Shinichi SHINOHARA  Risaburo SATO  

IEICE TRANSACTIONS on Communications   Vol.E83-B    No.3    pp.622-625
Publication Date: 2000/03/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section LETTER (Special Issue on Recent Progress in Electromagnetic Compatibility Technology)
digital IC,  package-pin,  voltage fluctuation,  voltage spectrum,  ferrite-resin composite,  

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This paper describes how voltage fluctuation in the DC power supply of a digital IC can be reduced, by means of molding the package-pin in a ferrite-resin composite. The voltage fluctuation of the DC power supply, when the input terminal was driven by a 40 MHz, 5 Vp-p pulse wave, was measured using an oscilloscope. Simultaneously, the voltage spectrum of the fluctuation was measured using a spectrum analyzer. As a result, the voltage fluctuation was decreased by about 50 % when the IC package-pins were molded in a ferrite-resin composite, in which the µiac of the ferrite powder equalled 100, and the powder content was 80 weight-%. In the same IC, there was the reduction effect of the voltage spectrum of the fluctuation was recognized in the frequency range 40 MHz to 1 GHz.