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Voltage supply circuit

Imported: 23 Feb '17 | Published: 22 Oct '02

Hiroyasu Inomata, Satoshi Yatabe

USPTO - Utility Patents

Abstract

A voltage supply circuit capable of starting up a system while maintaining symmetry of a high level selection signal V

H and a low level selection signal V

L, not requiring a multistage charge pump circuit, and capable of reducing the number of parts of the system, wherein generation circuits of V

D and V

H are comprised of chopper type booster type switching regulators, and switching timings of a V

H generation circuit

12 and a V

L generation circuit

13 are controlled so that a virtual reference voltage V

S (V

D/2) and a middle point potential between V

H and V

L become the same.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the configuration of a first embodiment of a voltage supply circuit according to the present invention.

FIG. 2 is a circuit diagram of a concrete example of the configuration of a signal electrode drive voltage generation circuit according to the present invention.

FIG. 3 is a circuit diagram of a concrete example of the configuration of a high level selection voltage generation circuit according to the present invention.

FIG. 4 is a circuit diagram of a concrete example of the configuration of a low level selection voltage generation circuit according to the present invention.

FIG. 5 is a flowchart for explaining an operation at the time of startup of the voltage supply circuit according to the present invention,

FIG. 6 is a flowchart for explaining an operation in a normal mode of the voltage supply circuit according to the present invention.

FIG. 7 is a view of the configuration of a second embodiment of the voltage supply circuit according to the present invention.

FIG. 8 is a view of the configuration of a third embodiment of the voltage supply circuit according to the present invention.

Claims

1. A voltage supply circuit comprising:

2. A voltage supply circuit as set forth in claim 1, wherein said control circuit makes said third voltage generation circuit operate when a voltage difference between said virtual reference voltage and said second output voltage is larger than the voltage difference between said virtual reference voltage and said third output voltage and makes said second voltage generation circuit operate when the voltage difference between said virtual reference voltage and said second output voltage is smaller than the voltage difference between said virtual reference voltage and said third output voltage.

3. A voltage supply circuit as set forth in claim 1 or 2, wherein said virtual reference voltage is a middle point potential between said first output voltage and a ground potential, and said intermediate potential is the middle point potential between said second output voltage and said third output voltage.

4. A voltage supply circuit as set forth in claim 2, wherein said second output voltage is higher than said third output voltage.