Method and apparatus for power supplying capable of effectively eliminating overshoot voltage

• US 20050116692A1
• Filed: 11/29/2004
• Published: 06/02/2005
• Est. Priority Date: 12/02/2003
• Status: Active Grant

• Current Assignee: RICOH Electronic Devices Co., Ltd. (Nisshinbo Holdings Incorporated)
• Original Assignee: Ricoh Company Limited
• Inventors: Sugiyama, Minoru
• Granted Patent: US 7,638,987 B2
• Time in Patent Office: Days
• US Class Current: 323/222
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

A power supply apparatus includes a switching transistor, a transistor control circuit, and a reference voltage generator. The switching transistor performs a switching operation for converting an input source voltage to an output power voltage according to a control signal. The transistor control circuit generates the control signal based on a reference voltage and a feedback voltage associated with the output power voltage. The reference voltage generator generates the reference voltage, increases the reference voltage in a phased manner to increase the output power voltage in a phased manner to a desired value, and decreases the reference voltage to decrease the output power voltage. A power supply method is also described.

Claims

1. A power supply apparatus comprising:

a switching transistor configured to perform a switching operation for converting an input source voltage to an output power voltage according to a control signal;

a transistor control circuit configured to generate said control signal based on a reference voltage and a feedback voltage associated with said output power voltage; and

a reference voltage generator configured to generate said reference voltage, to increase said reference voltage in a phased manner for increasing said output power voltage in a phased manner to a desired value, and to decrease said reference voltage for decreasing said output power voltage.

2. A power supply apparatus comprising:

an input terminal configured to receive an input source voltage;

an output terminal configured to output an output power voltage;

an inductor provided between said input terminal and said output terminal and configured to store energy of said input source voltage and discharge said energy to generate said output power voltage;

a switching transistor provided between said input terminal and said inductor and configured to control outputting of said input source voltage to said inductor by performing a switching operation according to a control signal input in the switching transistor;

an output power voltage detection circuit configured to detect said output power voltage to generate a feedback voltage proportional to said detected output power voltage;

a switching control circuit configured to control switching of said switching transistor to desirably change said output power voltage by comparing said feedback voltage with a predetermined reference voltage; and

a reference voltage generation circuit configured to generate and output said reference voltage, to increase said reference voltage in a phased manner for increasing said output power voltage in a phased manner to a desired value, and to decrease said reference voltage for decreasing said output power voltage.

3. The power supply apparatus as described in claim 2, wherein said reference voltage generation circuit comprises:

a D/A converter configured to convert digital data into said predetermined reference voltage; and

a DAC control circuit configured to output said digital data to said D/A converter for controlling said predetermined reference voltage to be output from said D/A converter, to change said digital data in a phased manner for increasing said reference voltage in a phased manner to a desired value, and to change said digital data for decreasing said reference voltage.

4. The power supply apparatus as described in claim 3, wherein said DAC control circuit has a conversion resolution that changes said reference voltage in a phased manner.

5. The power supply apparatus as described in claim 4, wherein said DAC control circuit changes said digital data bit-by-bit on a binary basis within said conversion resolution to increase said reference voltage in a phased manner.

6. The power supply apparatus as described in claim 2, wherein said power supply apparatus uses a non-isolated switching system.

7. A power supply apparatus comprising:

switching means for performing a switching operation for converting an input source voltage to an output power voltage according to a control signal;

control means for generating said control signal based on a reference voltage and a feedback voltage associated with said output power voltage; and

reference voltage generation means for generating said reference voltage, increasing said reference voltage in a phased manner to increase said output power voltage in a phased manner to a desired value, and decreasing said reference voltage to decrease said output power voltage.

8. A power supply apparatus comprising:

an input terminal configured to receive an input source voltage;

an output terminal configured to output an output power voltage;

an inductor provided between said input terminal and said output terminal and configured to store energy of said input source voltage and discharge said energy to generate said output power voltage;

switching means for controlling outputting of said input source voltage to said inductor by performing a switching operation according to a control signal;

output power voltage detection means for detecting said output power voltage to generate a feedback voltage proportional to said detected output power voltage;

switching control means for controlling switching of said switching means to desirably change said output power voltage by comparing said feedback voltage with a predetermined reference voltage; and

reference voltage generation means for generating and outputting said reference voltage, increasing said reference voltage in a phased manner to increase said output power voltage in a phased manner to a desired value, and decreasing said reference voltage to decrease said output power voltage.

9. The power supply apparatus as described in claim 8, wherein said reference voltage generation means comprises:

converting means for converting digital data into said predetermined reference voltage; and

conversion control means for outputting said digital data to said converting means to control said predetermined reference voltage to be output from said converting means, changing said digital data in a phased manner to increase said reference voltage in a phased manner to a desired value, and changing said digital data to decrease said reference voltage.

10. The power supply apparatus as described in claim 9, wherein said conversion control means has a conversion resolution that changes said reference voltage in a phased manner.

11. The power supply apparatus as described in claim 10, wherein said conversion control means changes said digital data bit-by-bit on a binary basis within said conversion resolution to increase said reference voltage in a phased manner.

12. The power supply apparatus as described in claim 8, wherein said power supply apparatus uses a non-isolated switching system.

13. A power supply method comprising:

applying an input source voltage;

providing an output terminal configured to output an output power voltage;

generating a reference voltage;

producing a control signal based on said reference voltage and a feedback voltage associated with said output power voltage;

performing a switching operation for converting an input source voltage to said output power voltage according to said control signal;

increasing said reference voltage in a phased manner to increase said output power voltage in a phased manner to a desired value; and

decreasing said reference voltage to decrease said output power voltage.

14. A power supply-method comprising:

providing a switching transistor between an input terminal and an inductor, said input terminal receiving an input source voltage, and said inductor having one end connected to an output terminal for outputting an output power voltage to a load;

detecting said output power voltage to produce a feedback voltage proportional to said detected output power voltage;

generating a predetermined reference voltage;

comparing said feedback voltage with said predetermined-reference voltage to output a control signal to said switching transistor;

performing a switching operation of said switching transistor by using said control signal;

repeating an operation of storing energy of said input source voltage in said inductor and discharging said energy from said inductor to generate said output power voltage to be output;

increasing said reference voltage in a phased manner to increase said output power voltage in a phased manner to a desired value; and

decreasing said reference voltage to decrease said output power voltage.

15. The power supply method as described in claim 14, wherein said generating step comprises:

outputting digital data; and

converting said digital data to said predetermined reference voltage,

wherein said outputting step changes said digital data in a phased manner to increase said reference voltage in a phased manner to a desired value, and changes said digital data to decrease said reference voltage.

16. The power supply method as described in claim 15, wherein said outputting step has a conversion resolution that changes said reference voltage in a phased manner.

17. The power supply method as described in claim 16, wherein said outputting step changes said digital data bit-by-bit on a binary basis within said conversion resolution to increase said reference voltage in a phased manner.

18. The power supply method as described in claim 14, wherein the power supply method uses a non-isolated switching system.