Leakage current blocking circuit and leakage current blocking method for decoupling capacitor
AssigneeRealtek Semiconductor Corp.
InventorHung-Der Su
Life of this patent
Estimating the term…
Abstract
A leakage current blocking circuit and a leakage current blocking method for a decoupling capacitor are provided. A first end of the decoupling capacitor is coupled to a power voltage. The leakage current blocking circuit is coupled between a second end of the decoupling capacitor and a ground voltage, and the leakage current blocking circuit includes at least one switch. The at least one switch is used to provide a channel for the decoupling capacitor to be coupled to the ground voltage when the decoupling capacitor is not damaged, and when the decoupling capacitor is damaged, the at least one switch is turned off to block a leakage current of the decoupling capacitor.
Claims8
A leakage current blocking circuit for a decoupling capacitor, wherein a first end of the decoupling capacitor is coupled to a power voltage, the leakage current blocking circuit is coupled between a second end of the decoupling capacitor and a ground voltage, and the leakage current blocking circuit comprises:
- at least one switch used to provide a channel allowing the decoupling capacitor to be coupled to the ground voltage when the decoupling capacitor is not damaged;
- wherein the at least one switch is turned off to block a leakage current of the decoupling capacitor when the decoupling capacitor is damaged;
- wherein the at least one switch is a first N-type MOSFET, a drain of the first N-type MOSFET is coupled to the second end of the decoupling capacitor, and a source of the first N-type MOSFET is coupled to the ground voltage;
- wherein the leakage current blocking circuit further includes:
- a second N-channel depletion-mode MOSFET, wherein a drain of the second N-channel depletion-mode MOSFET and the drain of the first N-type MOSFET are commonly coupled to the second end of the decoupling capacitor via a first node;
- and a source of the second N-channel depletion-mode MOSFET and a gate of the second N-channel depletion-mode MOSFET are commonly coupled to a second node;
- and
- an inverter, wherein an input end of the inverter is coupled to the second node, and an output end of the inverter is coupled to a gate of the first N-type MOSFET.
A leakage current blocking method for a decoupling capacitor, wherein a first end of the decoupling capacitor is coupled to a power voltage, and the leakage current blocking method comprises:
- providing a leakage current blocking circuit coupled between a second end of the decoupling capacitor and a ground voltage, wherein, at least one switch of the leakage current blocking circuit is used to provide a channel allowing the decoupling capacitor to be coupled to the ground voltage when the decoupling capacitor is not damaged;
- and
- the at least one switch of the leakage current blocking circuit being turned off so as to block a leakage current of the decoupling capacitor when the decoupling capacitor is damaged;
- wherein the at least one switch is a first N-type MOSFET, a drain of the first N-type MOSFET is coupled to the second end of the decoupling capacitor, and a source of the first N-type MOSFET is coupled to the ground voltage;
- wherein the leakage current blocking circuit further includes:
- a second N-channel depletion-mode MOSFET, wherein a drain of the second N-channel depletion-mode MOSFET and the drain of the first N-type MOSFET are commonly coupled to the second end of the decoupling capacitor via a first node;
- and a source of the second N-channel depletion-mode MOSFET and a gate of the second N-channel depletion-mode MOSFET are commonly coupled to a second node;
- and
- an inverter, wherein an input end of the inverter is coupled to the second node, and an output end of the inverter is coupled to a gate of the first N-type MOSFET.
Dependencies are inferred from the claim text.