Capacitive measurements with fast recovery current return
AssigneeElectro Scientific Industries, Inc.
InventorsDavid W. Newton, Kenneth V. Almonte
Life of this patent
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Abstract
An apparatus and method for measuring the leakage current of capacitive components. A switch that grounds a terminal of a component being tested is closed while the component is charged to a desired test voltage. When this charging is complete, the switch opens so that the diode terminal is at the same potential as the input amplifier's virtual ground. An accurate and fast measurement of the leakage current of the component can be measured.
Claims14
An apparatus for testing a capacitive component including a current source coupled to one terminal of the capacitive component and that supplies a current to the capacitive component to reach a desired test voltage and a meter coupled to a second terminal of the capacitive component that measures a leakage current across the capacitive component, the improvement comprising:
- a switch coupled between the second terminal of the capacitive component and ground;
- and
- a control device for the switch, the control device operable to:
- keep the switch closed while the current source supplies the current to capacitive component;
- and
- open the switch after the capacitive component reaches the desired test voltage at the one terminal and prior to measurement of the leakage current by the meter.
An apparatus for testing a capacitive component including a current source coupled to one terminal of the capacitive component and that supplies a current to the capacitive component to reach a desired test voltage and a meter coupled to a second terminal of the capacitive component that measures a leakage current across the capacitive component, the apparatus further comprising:
- a normally-closed switch coupled between the second terminal of the capacitive component and ground;
- and
- means for opening the normally-closed switch after the capacitive component reaches the desired test voltage at the one terminal and prior to measurement of the leakage current by the meter.
A method for testing a capacitive component using a current source coupled to one terminal of the capacitive component and a meter coupled to a second terminal of the capacitive component, the method comprising:
- A) charging the one terminal of the capacitive component to a desired test voltage using a current from the current source while a switch coupled between the second terminal of the capacitive component and ground is closed;
- B) opening the switch when the one terminal of the capacitive component reaches the desired test voltage;
- and
- C) measuring a leakage current of the capacitive component using the meter after opening the switch.
Dependencies are inferred from the claim text.