Title:
PWM CONTROL CIRCUIT AND SWITCHING POWER SUPPLY DEVICE
Document Type and Number:
WIPO Patent Application WO/2015/002125
Kind Code:
A1
Abstract:
Provided is a PWM control circuit in which a square wave signal having a discretionary frequency and duty ratio is input from a terminal (11), a modulation signal is input from a terminal (12), and two modified signals having different timing (phase) are output from terminals (21, 22). A first ramp wave generation circuit (31) generates a first ramp wave that is synchronized with the rising edge of the square wave signal. A second ramp wave generation circuit (32) generates a second ramp wave that is synchronized with the falling edge of the square wave signal. A first comparison circuit (32) generates a first modulated signal by inverting the level in accordance with the result of comparing the first ramp wave and the modulation signal. A second comparison circuit (42) generates a second modulated signal by inverting the level in accordance with the result of comparing the second ramp wave and the modulation signal. As a result, two PWM signals having a phase difference other than 180° are generated, and a quasi-square wave signal having a duty ratio other than 50% is obtained.
Inventors:
IJIRI YASUNORI (JP)
MITSUHASHI SOTARO (JP)
MITSUHASHI SOTARO (JP)
Application Number:
PCT/JP2014/067324
Publication Date:
January 08, 2015
Filing Date:
June 30, 2014
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H02M7/48
Foreign References:
| JPS62130016A | 1987-06-12 | |||
| JP2004282352A | 2004-10-07 | |||
| JPH03169255A | 1991-07-22 |
Attorney, Agent or Firm:
Kaede Patent Attorneys' Office (JP)
Patent business corporation Kaede Patent Attorneys' Office (JP)
Patent business corporation Kaede Patent Attorneys' Office (JP)
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