Hiroyuki Hirashima

US Patent:

6043998, Mar 28, 2000

Filed:

Jun 15, 1999

Appl. No.:

9/333272

Inventors:

Hiroyuki Hirashima - Vancouver WA
Masahiko Monomohshi - Kashihara, JP

Assignee:

Sharp Kabushiki Kaisha - Osaka

International Classification:

H02M 318

US Classification:

363 59

Abstract:

A voltage multiplying device of the present invention is provided with: a voltage multiplication level setting circuit for setting a voltage multiplying level which indicates how many times the power source voltage is multiplied; a voltage multiplication pulse signal generating circuit for outputting a plurality of voltage multiplication pulse signals, each having a predetermined period and varying with a predetermined phase difference; a condition decoder circuit and a voltage multiplication pulse selecting circuit for outputting a voltage multiplication controlling signal, which varies in accordance with the determined voltage multiplication level, in synchronization with the pulse signal; and a voltage multiplication level outputting circuit for multiplying the power source voltage step by step to the set voltage multiplication level in accordance with the voltage multiplication controlling signal and for outputting the voltage multiplication level in each of the steps. This arrangement makes it possible to obtain a plurality of voltage multiplication levels by using a single voltage multiplying device, without changing a circuit connection.