Method and apparatus for electrostatic discharge protection
AssigneeFairchild Semiconductor Corporation
InventorGuangchun Tian
Life of this patent
Estimating the term…
Abstract
This application discusses, among other things, apparatus and methods for electrostatic discharge (ESD) protection. In an example, an ESD protection circuit can include an ESD control circuit, and a driver-off circuit, wherein the ESD control circuit is configured to send an enable signal to the driver-off circuit and to perform electrostatic discharge to a ground node when detecting occurrence of electrostatic charges, and wherein the driver-off circuit is configured to disable a driving device upon reception of the enable signal.
Claims15
An Electrostatic Discharge (ESD) protection circuit configured to couple to an output terminal driven by an output transistor, the ESD protection circuit comprising:
- an ESD detection circuit;
- an ESD protection circuit including an ESD protection transistor, the ESD protection transistor distinct from the output transistor;
- and
- a power supply control circuit including:
- a power supply detection circuit configured to detect a state of a power supply;
- and
- an ESD-off transistor, wherein the ESD-off transistor is configured to control a control node of the ESD protection transistor when a power supply is in a normal “on” state;
- wherein the ESD detection circuit is configured to send an enable signal to the ESD protection circuit;
- wherein the an ESD protection transistor is configured to perform electrostatic discharge directly to a ground node upon reception of the enable signal.
A driving circuit comprising:
- an ESD protection circuit including an ESD protection transistor, the ESD protection circuit configured to detect an occurrence of electrostatic charges;
- and
- a driving device distinct from the ESD protection transistor;
- and
- a power supply detection circuit including an ESD-off transistor, the ESD-off transistor configured to control a control node of the ESD protection transistor when a power supply is in a normal “on” state;
- wherein the ESD protection circuit is configured to disable the driving device,
- wherein the ESD protection transistor is configured to perform electrostatic discharge to a ground node during the occurrence of electrostatic charges;
- and
- wherein the driving device is configured to output, during normal operation, a driving signal.
An ESD protection method for protecting an output terminal, configured to be driven by an driving device, from damage due to an occurrence of electrostatic charge, the method comprising:
- detecting the occurrence of electrostatic charge using and ESD protection circuit;
- providing an ESD enable signal to an ESD protection transistor, the ESD protection transistor distinct from the driving device;
- performing electrostatic discharge directly to a ground node using the ESD protection transistor in response to the ESD enable signal;
- detecting whether a power supply is normal by using a power supply control circuit;
- and
- when detecting that the power supply is normal, controlling a control node of the ESD protection transistor using a ESD-off transistor of the power supply control circuit to disable the ESD protection transistor from discharging charge to ground, such that the ESD protection transistor does not interfere with a driving signal output from the driving device.
Dependencies are inferred from the claim text.