Electrostatic Discharge (ESD) Protection Circuit with EOS and Latch-Up Immunity

• US 20140355157A1
• Filed: 05/22/2014
• Published: 12/04/2014
• Est. Priority Date: 05/28/2013
• Status: Active Grant

• Current Assignee: Princeton Technology Corporation
• Original Assignee: Princeton Technology Corporation
• Inventors: HUANG, Mine-Yuan, CHI, Li-Hung
• Granted Patent: US 9,634,483 B2
• Time in Patent Office: Days
• US Class Current: 361/56
• CPC Class Codes: H01L 27/0248 for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection
• CPC Class Codes: H01L 27/0921 Means for preventing a bipolar, e.g. thyristor, action between the different transistor regions, e.g. Latchup prevention
• CPC Class Codes: H02H 9/041 using a short-circuiting device
• CPC Class Codes: H02H 9/043 Protection of over-voltage protection device by short-circuiting
• CPC Class Codes: H02H 9/046 responsive to excess voltage appearing at terminals of integrated circuits protection by specific structural integration design H01L27/0248

Abstract

An electrostatic discharge (ESD) protection circuit with electrical overstress (EOS) and latch-up immunity has a main ESD circuit, a voltage detection circuit and an electrostatic driving circuit. The main ESD circuit is coupled between a first rail and a second rail and has a control end. The main ESD circuit is configured to establish an electrical connection between the first rail and the second rail based on a voltage of the control end. The voltage detection circuit is coupled between the first rail and the second rail for setting the voltage of the control end when a voltage of the first rail is greater than a limiting voltage. The electrostatic driving circuit is used to drive the main ESD circuit when an ESD phenomenon occurs.

Claims

1. An electrostatic discharge protection circuit, comprising:

a main electrostatic discharge (ESD) circuit, coupled between a first rail and a second rail, and having a control end, wherein the main ESD circuit is arranged to establish an electrical connection between the first rail and the second rail based on a voltage of the control end;

a voltage detection circuit, coupled between the first rail and the second rail for setting the voltage at the control end when a voltage of the first rail is greater than a limiting voltage, thereby driving the main ESD circuit to establish the electrical connection between the first rail and the second rail; and

an electrostatic driving circuit, coupled between the main ESD circuit and the control end for setting the voltage at the control end when an instant variation of the voltage at the first rail is greater than a predetermined value, thereby driving the main ESD circuit to establish the electrical connection between the first rail and the second rail.

2. The electrostatic discharge protection circuit as claimed in claim 1, wherein the voltage detection circuit comprises:

a first switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the first switch is coupled to the first rail;

a limiting voltage setup circuit, having a first terminal and a second terminal, wherein the limiting voltage setup circuit is coupled between the control terminal of the first switch and the second rail for establishing an electrical connection between the first terminal of the limiting voltage setup circuit and the second terminal of the limiting voltage setup circuit when voltage at the first rail is greater than the limiting voltage;

a first resistor, having a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the second terminal of the first switch, and the second terminal of the first resistor is coupled to the second rail; and

a second switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the second switch is coupled to the electrostatic driving circuit, the second terminal of the second switch is coupled to the second rail, and the control terminal of the second switch is coupled to the second terminal of the first switch and the first terminal of the first resistor.

3. The electrostatic discharge protection circuit as claimed in claim 1, wherein the voltage detection circuit comprises:

a resistor, having a first terminal and a second terminal, wherein the second terminal of the resistor is coupled to the second rail;

a limiting voltage setup circuit, having a first terminal and a second terminal, wherein the first terminal of the limiting voltage setup circuit is coupled to the first rail, the second terminal of the limiting voltage setup circuit is coupled to the first terminal of the resistor, and wherein the limiting voltage setup circuit is arranged to establish an electrical connection between the first terminal of the limiting voltage setup circuit and the second terminal of the limiting voltage setup circuit when voltage at the first rail is greater than the limiting voltage; and

a switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the switch is coupled to the electrostatic driving circuit, the second terminal of the switch is coupled to the second rail, and the control terminal of the switch is coupled to the second terminal of the limiting voltage setup circuit and the first terminal of the resistor.

4. The electrostatic discharge protection circuit as claimed in claim 1, wherein the voltage detection circuit comprises:

a limiting voltage setup circuit, having a first terminal and a second terminal, wherein the first terminal of the limiting voltage setup circuit is coupled to the first rail, and wherein the limiting voltage setup circuit is arranged to establish an electrical connection between the first terminal of the limiting voltage setup circuit and the second terminal of the limiting voltage setup circuit when voltage at the first rail is greater than the limiting voltage;

a first switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the first switch is coupled to the second terminal of the limiting voltage setup circuit;

a first resistor, having a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the control terminal of the first switch, and the second terminal of the first resistor is coupled to the second rail;

a second resistor, having a first terminal and a second terminal, wherein the first terminal of the second resistor is coupled to the second terminal of the first switch, and the second terminal of the second resistor is coupled to the second rail; and

a second switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the second switch is coupled to the electrostatic driving circuit, the second terminal of the second switch is coupled to the second rail, and the control terminal of the second switch is coupled to the second terminal of the first switch and the first terminal of the second resistor.

5. The electrostatic discharge protection circuit as claimed in claim 1, wherein the voltage detection circuit comprises:

a first switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the first switch is coupled to the first rail;

a limiting voltage setup circuit, having a first terminal and a second terminal, wherein the limiting voltage setup circuit is coupled between the control terminal of the first switch and the second rail, the limiting voltage setup circuit is arranged to establish an electrical connection between the first terminal of the limiting voltage setup circuit and the second terminal of the limiting voltage setup circuit when voltage at the first rail is greater than the limiting voltage;

a first resistor, having a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the second terminal of the first switch, and the second terminal of the first resistor is coupled to the second rail; and

a second switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the second switch is coupled to the control end of the main ESD circuit, the control terminal of the second switch is coupled to the second terminal of the first switch and the first terminal of the first resistor, and the second terminal of the second switch is coupled to the second rail.

6. The electrostatic discharge protection circuit as claimed in claim 5, wherein the voltage detection circuit further comprises:

a second resistor, coupled to the limiting voltage setup circuit in series between the control terminal of the first switch and the second rail.

7. The electrostatic discharge protection circuit as claimed in claim 1, wherein the voltage detection circuit comprises:

a first resistor, having a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the first rail;

a limiting voltage setup circuit, having a first terminal and a second terminal, wherein the first terminal of the limiting voltage setup circuit is coupled to the second terminal of the first resistor, and the second terminal of the limiting voltage setup circuit is coupled to the second rail, and wherein the limiting voltage setup circuit is arranged to establish an electrical connection between the first terminal of the limiting voltage setup circuit and the second terminal of the limiting voltage setup circuit when voltage at the first rail is greater than the limiting voltage;

a first switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the first switch is coupled to the first rail, the control terminal of the first switch is coupled to the second terminal of the first resistor and the first terminal of the limiting voltage setup circuit;

a second resistor, having a first terminal and a second terminal, wherein the first terminal of the second resistor is coupled to the second terminal of the first switch, and the second terminal of the second resistor is coupled to the second rail;

a third resistor, having a first terminal and a second terminal, wherein the first terminal of the third resistor is coupled to the first rail;

a second switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the second switch is coupled to the second terminal of the third resistor, the second terminal of the second switch is coupled to the second rail, and the control terminal of the second switch is coupled to the second terminal of the first switch and the first terminal of the second resistor; and

a third switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the third switch is coupled to the first rail, the second terminal of the third switch is coupled to the electrostatic driving circuit, and the control terminal of the third switch is coupled to the first terminal of the second switch and the second terminal of the third resistor.

8. The electrostatic discharge protection circuit as claimed in claim 7, wherein the electrostatic driving circuit comprises a resistor, a capacitor and an inverter, and wherein the resistor of the electrostatic driving circuit and the capacitor of the electrostatic driving circuit are coupled in series with each other between the first rail and the second rail, the resistor of the electrostatic driving circuit and the capacitor of the electrostatic driving circuit are coupled to an input terminal of the inverter, and an output terminal of the inverter is coupled to the control end of the main ESD circuit.

9. The electrostatic discharge protection circuit as claimed in claim 1, wherein the voltage detection circuit comprises:

a limiting voltage setup circuit, having a first terminal and a second terminal, wherein the first terminal of the limiting voltage setup circuit is coupled to the first rail, and the limiting voltage setup circuit is arranged to establish an electrical connection between the first terminal of the limiting voltage setup circuit and the second terminal of the limiting voltage setup circuit when voltage at the first rail is greater than the limiting voltage;

a first resistor, having a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the second terminal of the limiting voltage setup circuit, and the second terminal of the first resistor is coupled to the second rail; and

a first switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the first switch is coupled to the control end of the main ESD circuit, the second terminal of the first switch is coupled to the second rail, and the control terminal of the first switch is coupled to the second terminal of the limiting voltage setup circuit and the first terminal of the first resistor.

10. The electrostatic discharge protection circuit as claimed in claim 9, wherein the electrostatic driving circuit comprises a resistor and a capacitor, and wherein a first terminal of the resistor of the electrostatic driving circuit is coupled to the first rail, a second terminal of the resistor of the electrostatic driving circuit and a first terminal of the capacitor of the electrostatic driving circuit are coupled with each other to the control end of the main ESD circuit, and a second terminal of the capacitor of the electrostatic driving circuit is coupled to the second rail.

11. The electrostatic discharge protection circuit as claimed in claim 1, wherein the voltage detection circuit comprises:

a limiting voltage setup circuit, having a first terminal and a second terminal, wherein the first terminal of the limiting voltage setup circuit is coupled to the first rail, and the limiting voltage setup circuit is arranged to establish an electrical connection between the first terminal of the limiting voltage setup circuit and the second terminal of the limiting voltage setup circuit when voltage at the first rail is greater than the limiting voltage;

a first resistor, having a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the second terminal of the limiting voltage setup circuit, and the second terminal of the first resistor is coupled to the second rail;

a current mirror circuit, having a first terminal, a second terminal and a third terminal, wherein the first terminal of the current mirror circuit is coupled to the first rail, and the third terminal of the current mirror circuit is coupled to the control end of the main ESD circuit; and

a first switch, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the first switch is coupled to the second terminal of the current mirror circuit, the second terminal of the first switch is coupled to the second rail, and the control terminal of the first switch is coupled to the second terminal of the limiting voltage setup circuit and the first terminal of the first resistor.

12. The electrostatic discharge protection circuit as claimed in claim 11, wherein the electrostatic driving circuit comprises a second resistor, having a first terminal coupled to the control end of the main ESD circuit, and a second terminal coupled to the second rail.

13. The electrostatic discharge protection circuit as claimed in claim 11, wherein the main ESD circuit comprises a fourth switch, having a first terminal coupled to the first rail, a second terminal coupled to the second rail, and a control terminal coupled to the control end of the main ESD circuit.

14. The electrostatic discharge protection circuit as claimed in claim 11, wherein the limiting voltage setup circuit includes a zener diode, a plurality of serially-connected diodes, or a plurality of serially-connected transistors.