ESD protection circuit and ESD protection method thereof
AssigneeSilicon Motion, Inc.
InventorTe-Wei Chen
Life of this patent
Estimating the term…
Abstract
The present invention provides an ESD protection circuit including a discharge transistor, a first switch, a second switch, a third switch and a fourth switch. The discharge transistor forms a discharge path between a first voltage terminal and a second voltage terminal. The first switch selectively provides voltage at the first voltage terminal to a control terminal of the discharge transistor. The second switch selectively provides voltage at the second voltage terminal to the control terminal of the discharge transistor. The third switch selectively provides voltage at the first voltage terminal to a substrate of the discharge transistor. The fourth switch selectively provides voltage at second voltage terminal to the substrate of the discharge transistor.
Claims26
An ESD protection circuit, comprising:
- a first voltage terminal;
- a second voltage terminal;
- a discharge transistor, having a first terminal coupled to the first voltage terminal, a second terminal coupled to the second voltage terminal, a control terminal coupled to a first node, and a substrate coupled to a second node, wherein the discharge transistor forms a discharge path between the first voltage terminal and the second voltage terminal;
- a first switch, coupled between the first voltage terminal and the first node, arranged to selectively provide voltage at the first voltage terminal to the control terminal of the discharge transistor;
- a second switch, coupled between the first node and the second voltage terminal, arranged to selectively provide voltage at the second voltage terminal to the control terminal of the discharge transistor;
- a third switch, coupled between the first voltage terminal and the second node, arranged to selectively provide voltage at the first voltage terminal to the substrate of the discharge transistor;
- and
- a fourth switch, coupled between the second node and the second voltage terminal, arranged to selectively provide voltage at the second voltage terminal to the substrate of the discharge transistor.
An ESD protection method, applied to an ESD protection circuit, wherein the ESD protection circuit comprises a discharge transistor, a first switch, a second switch, a third switch and a fourth switch, the ESD protection method comprising:
- selectively providing voltage at a first voltage terminal or a second voltage terminal to a control terminal of the discharge transistor by the first switch or the second switch according to the voltage at the first voltage terminal and the second voltage terminal to turn on the discharge transistor;
- selectively providing the voltage at the first voltage terminal or the second voltage terminal to a substrate of the discharge transistor by the third switch or the fourth switch according to the voltage of the first voltage terminal or the second voltage terminal to turn on the discharge transistor;
- and
- discharging current of the first voltage terminal to the second voltage terminal by the discharge transistor, or discharging current of the second voltage terminal to the first voltage terminal by the discharge transistor.
Dependencies are inferred from the claim text.