POWER SUPPLY APPARATUS, TEST APPARATUS, AND ELECTRONIC DEVICE

• US 20080297121A1
• Filed: 06/01/2007
• Published: 12/04/2008
• Est. Priority Date: 06/01/2007
• Status: Active Grant

• Current Assignee: Advantest Corporation
• Original Assignee: Advantest Corporation
• Inventors: MATSUDA, MINEKI
• Granted Patent: US 7,969,124 B2
• Time in Patent Office: Days
• US Class Current: 323/220
• CPC Class Codes: G05F 1/62 using bucking or boosting dc sources

Abstract

There is provided a power supply apparatus including a power supply section that supplies an output current to an external load, and a current control section that flows an electric current varying in a direction opposite to a supply current being supplied to the power supply section into a ground of the power supply section.

Claims

1. A power supply apparatus comprising:

a power supply section that supplies an output current to an external load; and

a current control section that flows an electric current varying in a direction opposite to a supply current being supplied to the power supply section into a ground of the power supply section.

2. The power supply apparatus as claimed in claim 1, wherein the current control section flows an analog current varying in a direction opposite to the supply current into the ground of the power supply section.

3. The power supply apparatus as claimed in claim 2, wherein

the current control section comprises:

a current detecting section that detects an external current being supplied from an external power supply apparatus connected to this power supply apparatus;

a variable current circuit that is connected between a current supplying line for supplying the supply current to the power supply section and the ground of the power supply section; and

a control section that controls an electric current flowed by the variable current circuit from the current supplying line to the ground of the power supply section, in order to bring the external current detected by the current detecting section close to a preset reference current.

4. The power supply apparatus as claimed in claim 3, wherein the control section flows an electric current obtained by subtracting the reference current from the external current from the current supplying line to the ground of the power supply section.

5. The power supply apparatus as claimed in claim 3, wherein the control section reduces the reference current, on condition that a value obtained by subtracting the supply current from the reference current is larger than a preset reference offset current, for a predetermined period.

6. The power supply apparatus as claimed in claim 3, wherein the control section increases the reference current on condition that a value obtained by subtracting the supply current from the reference current becomes smaller than a preset reference offset current.

7. The power supply apparatus as claimed in claim 2, wherein

the current control section comprises:

a variable current circuit that is connected between an external current line for inputting an external current being supplied from an external power supply apparatus connected to this power supply apparatus and the ground of the power supply section;

a current detecting section that detects the supply current; and

a control section that controls the variable current circuit so that an electric current varying in a direction opposite to the supply current detected by the current detecting section flows from an external current input terminal to the ground.

8. A test apparatus that tests a device under test,

the test apparatus comprising:

a test section that tests the device under test;

a power supply apparatus that supplies an output current to the device under test; and

a main power supply that outputs a main power supply current for operating the power supply apparatus, and the power supply apparatus comprising;

a power supply section that supplies the output current to the device under test; and

a current control section that flows an electric current varying in a direction opposite to a supply current being supplied to the power supply section into a ground of the power supply section.

9. The test apparatus as claimed in claim 8, wherein

the current control section comprises:

a current detecting section that detects a main power supply current being supplied from the main power supply; and

a variable current circuit and a switch that are serially connected between a current supplying line for supplying the supply current to the power supply section and the ground of the power supply section; and

a control section that controls an electric current flowed by the variable current circuit from the current supplying line to the ground of the power supply section, in order to bring the main power supply current detected by the current detecting section close to a preset reference current, and

the test section;

disconnects the switch for a test period for which the output current being supplied to the device under test is fluctuated within a predetermined reference range; and

connects the switch for a test period for which the output current being supplied to the device under test is fluctuated outside the reference range.

10. An electronic device comprising:

an electronic circuit;

a power supply section that supplies an output current to the electronic circuit; and

a current control section that flows an electric current varying in a direction opposite to a supply current being supplied to the power supply section into a ground of the power supply section.