Electrostatic discharge protection circuit and integrated circuit having electrostatic discharge protection mechanism

Abstract

This invention provides an electrostatic discharge (ESD) protection circuit and an integrated circuit with an ESD protection mechanism. Inside the integrated circuit, the ESD protection circuit executes the ESD protection mechanism. The ESD protection circuit detects the integrated circuit to determine if an ESD event has occurred. When an ESD event occurs, the ESD protection circuit directs the electrostatic energy to itself, and then to a ground terminal outside the drive circuit, preventing damage to the core integrated circuit.

Claims

1. An electrostatic discharge (ESD) protection circuit, applicable to an integrated circuit, the ESD protection circuit comprising: an ESD clamping circuit connected to the integrated circuit and an external ground terminal, configured to detect the integrated circuit to determine whether an ESD event has occurred in the integrated circuit; wherein, When the electrostatic event occurs in the integrated circuit, the electrostatic discharge clamping circuit guides the electrostatic energy inside the integrated circuit to the electrostatic discharge clamping circuit, and then guides the electrostatic energy to the external ground terminal outside the integrated circuit; wherein the plurality of pins of the integrated circuit includes a first power supply pin and a second power supply pin; wherein the electrostatic discharge clamping circuit includes: an electrostatic discharge path circuit, connecting the plurality of pins, and connecting to the external ground terminal through one of the pins; a charging time detection circuit, connected between the first power supply pin and the second power supply pin, configured to detect when a power signal between the first power supply pin and the second power supply pin is coupled to a start-up potential after a charging time, and outputs a detection time start-up signal; A voltage detection circuit, connected between the first power supply pin and the second power supply pin, is configured to output an overvoltage signal when a voltage level of the power signal reaches a start-up potential; and an electrostatic discharge start-up circuit, connected to the charging time detection circuit, the voltage detection circuit, and the electrostatic discharge path circuit, is configured to control the electrostatic discharge path circuit to conduct according to the detection time start-up signal and the overvoltage signal.

2. The electrostatic discharge protection circuit as claimed in claim 1, wherein the electrostatic discharge clamping circuit is connected to a plurality of pins of the integrated circuit and configured to detect the electrostatic energy of one or more of the plurality of pins or one or more nodes connected thereto, thereby determining whether the electrostatic event has occurred in the integrated circuit.

3. The electrostatic discharge protection circuit as claimed in claim 1, wherein the charging time detection circuit includes a plurality of chargeable elements, and the electrostatic discharge initiation circuit includes a start-up switch element and a drive switch element; wherein the plurality of chargeable elements are connected in series between the first power supply pin and the second power supply pin, the control terminal of the start-up switch element is connected to a voltage node between two chargeable elements, and the first terminal of the start-up switch element and the input terminal of the voltage detection circuit are connected to the first power supply pin; wherein the output terminal of the voltage detection circuit is connected to the control terminal of the drive switch element, the first terminal of the drive switch element is connected to the second terminal of the start-up switch element, and the second terminal of the drive switch element is connected to the control terminal of the electrostatic discharge path circuit.

4. The electrostatic discharge protection circuit as claimed in claim 1, wherein the charging time detection circuit includes a plurality of chargeable elements, and the electrostatic discharge initiation circuit includes a start-up switch element; wherein the plurality of chargeable elements are connected in series between the first power supply pin and the second power supply pin, and the input terminal of the voltage detection circuit is connected to the first power supply pin; wherein the control terminal of the start-up switch element is connected to a voltage node between two of the chargeable elements, the first terminal of the start-up switch element is connected to the output terminal of the voltage detection circuit, and the second terminal of the start-up switch element is connected to the control terminal of the electrostatic discharge path circuit.

5. The electrostatic discharge protection circuit as claimed in claim 1, wherein the charging time detection circuit includes a plurality of chargeable elements, and the electrostatic discharge initiation circuit includes a start-up switch element; wherein the plurality of chargeable elements are connected in series between the first power supply pin and the second power supply pin, a first end of the start-up switch element is connected to the first power supply pin, a control end of the start-up switch element is connected to a voltage node between two chargeable elements, a second end of the start-up switch element is connected to the input end of the voltage detection circuit, and the output end of the voltage detection circuit is connected to the control end of the electrostatic discharge path circuit.

6. An electrostatic discharge (ESD) protection circuit, applicable to a drive circuit, wherein the drive circuit includes a plurality of input terminals, the plurality of input terminals including a plurality of power receiving terminals, the ESD protection circuit comprising: an ESD clamping circuit connected to each of the power receiving terminals and an external ground terminal, configured to: detect a power signal at each of the power receiving terminals to determine whether an ESD event has occurred in the drive circuit; and, upon determining that an ESD event has occurred, guide electrostatic energy to the ESD clamping circuit, and then guide the electrostatic energy to the external ground terminal outside the drive circuit.

7. The electrostatic discharge protection circuit as claimed in claim 6, wherein the plurality of power receiving terminals include a first power receiving terminal and a second power receiving terminal, the first power receiving terminal being connected to a first input node and the first input node being connected to a first input power supply, the second power receiving terminal being connected to a second input node and the first input node being connected to a second input power supply, the electrostatic discharge clamping circuit comprising: an electrostatic discharge path circuit connected between the first input node and the second input node; and an electrostatic event detection circuit connected between the first input node and the second input node and connected to the control terminal of the electrostatic discharge path circuit, configured to detect the electrostatic energy of the first input node or the second input node and, when determining that the drive circuit has suffered the electrostatic event, control the electrostatic discharge path circuit to conduct.

8. The electrostatic discharge protection circuit as claimed in claim 7, wherein the electrostatic event detection circuit comprises: a charging time detection circuit connected to the first input node, configured to output a detection time start signal when the electrostatic energy of the first input node is coupled to a start potential after a charging time; a voltage detection circuit connected to the first input node, configured to output an overvoltage signal when the electrostatic energy of the first input node reaches a start potential; and an electrostatic discharge start circuit connected to the charging time detection circuit and the voltage detection circuit, configured to drive the electrostatic discharge path circuit according to the detection time start signal and the overvoltage signal.

9. The electrostatic discharge protection circuit as claimed in claim 8, wherein the charging time detection circuit includes a plurality of chargeable elements, the electrostatic discharge initiation circuit includes a start-up switch element, and the electrostatic discharge initiation circuit includes a start-up switch element and a drive switch element; wherein the plurality of chargeable elements are connected in series between a first input node and a second input node, the control terminal of the start-up switch element is connected to a voltage node between two chargeable elements, the first terminal of the start-up switch element and the input terminal of the voltage detection circuit are connected to the first input node; wherein the output terminal of the voltage detection circuit is connected to the control terminal of the drive switch element, the first terminal of the drive switch element is connected to the second terminal of the start-up switch element, and the second terminal of the drive switch element is connected to the control terminal of the electrostatic discharge path circuit.

10. The electrostatic discharge protection circuit of claim 8, wherein the charging time detection circuit includes a plurality of chargeable elements, and the electrostatic discharge initiation circuit includes a start-up switch element; wherein the plurality of chargeable elements are connected in series between a first input node and a second input node, and the input terminal of the voltage detection circuit is connected to the first input node; wherein the control terminal of the start-up switch element is connected to a voltage node between two of the chargeable elements, a first terminal of the start-up switch element is connected to the output terminal of the voltage detection circuit, and a second terminal of the start-up switch element is connected to the control terminal of the electrostatic discharge path circuit.

11. The electrostatic discharge protection circuit as claimed in claim 8, wherein the charging time detection circuit includes a plurality of chargeable elements, and the electrostatic discharge initiation circuit includes a start-up switch element; wherein the plurality of chargeable elements are connected in series between the first input node and the second input node, a first end of the start-up switch element is connected to the first input node, a control end of the start-up switch element is connected to a voltage node between two of the chargeable elements, a second end of the start-up switch element is connected to the input end of the voltage detection circuit, and the output end of the voltage detection circuit is connected to the control end of the electrostatic discharge path circuit.

12. An integrated circuit with an electrostatic discharge protection mechanism, comprising: a driving circuit, wherein the driving circuit includes a plurality of input terminals, the plurality of input terminals including a plurality of power receiving terminals; and an electrostatic discharge clamping circuit connected to each of the power receiving terminals and an external ground terminal, configured to: detect a power signal of each of the power receiving terminals to determine whether an electrostatic event has occurred inside the integrated circuit; and when the electrostatic event is determined to have occurred, guide the electrostatic energy inside the integrated circuit to the electrostatic discharge clamping circuit, and then guide the electrostatic energy to the external ground terminal outside the integrated circuit.

13. An integrated circuit with an electrostatic discharge protection mechanism as described in claim 12, wherein the plurality of power receivers include a first power receiver and a second power receiver, the first power receiver being connected to a first input node and the first input node being connected to a first input power supply, the second power receiver being connected to a second input node and the second input node being connected to a second input power supply, the electrostatic discharge clamping circuit comprising: an electrostatic discharge path circuit connected between the first input node and the second input node; and an electrostatic event detection circuit connected between the first input node and the second input node and connected to a control terminal of the electrostatic discharge path circuit, configured to detect the power signal of the first input node or the second input node and, upon determining that the drive circuit has suffered an electrostatic event, control the electrostatic discharge path circuit to turn on.

14. An integrated circuit with an electrostatic discharge protection mechanism as described in claim 13, wherein the electrostatic event detection circuit comprises: a charging time detection circuit connected to the first input node, configured to output a detection time start signal when the power signal of the first input node is coupled to a start potential after a charging time; a voltage detection circuit connected to the first input node, configured to output an overvoltage signal when the power signal of the first input node reaches a start potential; and an electrostatic discharge start circuit connected to the charging time detection circuit and the voltage detection circuit, configured to drive the electrostatic discharge path circuit according to the detection time start signal and the overvoltage signal.

15. An integrated circuit with an electrostatic discharge protection mechanism as claimed in claim 14, wherein the charging time detection circuit includes a plurality of chargeable elements, and the electrostatic discharge initiation circuit includes a start-up switch element and a drive switch element; wherein the plurality of chargeable elements are connected in series between a first input node and a second input node, the control terminal of the start-up switch element is connected to a voltage node between two of the chargeable elements, and a first terminal of the start-up switch element and an input terminal of the voltage detection circuit are connected to the first input node; wherein the output terminal of the voltage detection circuit is connected to the control terminal of the drive switch element, the first terminal of the drive switch element is connected to the second terminal of the start-up switch element, and the second terminal of the drive switch element is connected to the control terminal of the electrostatic discharge path circuit.

16. An integrated circuit with an electrostatic discharge protection mechanism as claimed in claim 14, wherein the charging time detection circuit includes a plurality of charged elements, and the electrostatic discharge initiation circuit includes a start-up switch element; wherein the plurality of charged elements are connected in series between a first input node and a second input node, and the input terminal of the voltage detection circuit is connected to the first input node; wherein the control terminal of the start-up switch element is connected to a voltage node between two of the charged elements, a first terminal of the start-up switch element is connected to the output terminal of the voltage detection circuit, and a second terminal of the start-up switch element is connected to the control terminal of the electrostatic discharge path circuit.

17. An integrated circuit with an electrostatic discharge protection mechanism as claimed in claim 14, wherein the charging time detection circuit includes a plurality of chargeable elements, and the electrostatic discharge initiation circuit includes a start-up switch element; wherein the plurality of chargeable elements are connected in series between a first input node and a second input node, a first end of the start-up switch element is connected to the first input node, a control end of the start-up switch element is connected to a voltage node between two of the chargeable elements, a second end of the start-up switch element is connected to the input end of the voltage detection circuit, and the output end of the voltage detection circuit is connected to the control end of the electrostatic discharge path circuit.

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