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US 9,425,616 B2Granted
RC triggered ESD protection device
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYen-Lin Liu, Kuo-Ji Chen, Tzu-Yi Yang
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Abstract
An RC triggered ESD protection device comprises a discharge transistor, a driver circuit and a trigger circuit. The trigger circuit comprises a plurality of native NMOS transistors connected in parallel with a plurality of PMOS transistors operating as resistors. The relatively small resistance of the plurality of native NMOS transistors helps to keep a stable RC time constant value so that the ESD protection device can avoid a leakage current during a power up operation.
Claims20
A device comprising:
- a native n-type metal oxide semiconductor (NMOS) transistor having a first drain/source region directly connected to a first voltage potential and a second drain/source region directly connected to a first terminal of a capacitor, wherein a gate of the native NMOS transistor is connected to the first terminal of the capacitor, and wherein parameter values of the native NMOS transistor are selected such that the native NMOS transistor functions as a pull-up resistor;
- a resistance element connected between the first voltage potential and the first terminal of the capacitor, wherein the resistance element comprises at least a p-type metal oxide semiconductor (PMOS) transistor, and wherein the resistance element has at least two resistance values, and wherein a first resistance value of the resistance element is greater than a resistance value of the pull-up resistor, and a second resistance value of the resistance element is less than the resistance value of the pull-up resistor;
- and
- the capacitor having a second terminal coupled to a second voltage potential, wherein the first voltage potential is higher than the second voltage potential, and wherein the native NMOS transistor, the resistance element and the capacitor form an electrostatic discharge (ESD) trigger circuit.
1 more element
A system comprising:
- a discharge transistor coupled between a first voltage potential and a second voltage potential;
- a driver circuit generating an output signal fed to a gate terminal of the discharge transistor;
- and
- a trigger device having an output coupled to the driver circuit comprising:
- a native n-type metal oxide semiconductor (NMOS) transistor having a first drain/source region directly connected to the first voltage potential and a second drain/source region directly connected to a first terminal of a capacitor, wherein a gate of the native NMOS transistor is connected to the first terminal of the capacitor, and wherein parameter values of the native NMOS transistor are selected such that the native NMOS transistor functions as a pull-up resistor;
- a resistance element connected between the first voltage potential and the first terminal of the capacitor, wherein the resistance element comprises at least a p-type metal oxide semiconductor (PMOS) transistor, and wherein the resistance element has at least two resistance values, and wherein a first resistance value of the resistance element is greater than a resistance value of the native NMOS transistor, and a second resistance value of the resistance element is less than the resistance value of the native NMOS transistor;
- and
- the capacitor having a second terminal coupled to the second voltage potential, wherein the first voltage potential is higher than the second voltage potential.
5 more elements
An Electrostatic Discharge (ESD) clamp comprising:
- a resistor-capacitor (RC) trigger circuit coupled between a first voltage potential and a second voltage potential comprising:
- a capacitor formed by a plurality of metal oxide semiconductor (MOS) capacitors, wherein the capacitor has a first terminal coupled to the second voltage potential;
- and
- a resistance element comprising a plurality of MOS transistors and a plurality of native transistors, wherein the plurality of native transistors are connected in parallel with the plurality of MOS transistors, and wherein the resistance element has a terminal directly connected to the first voltage potential and the first voltage potential is higher than the second voltage potential, and wherein gates of the plurality of native transistors are directly connected to a second terminal of the capacitor, wherein the resistance element has at least two resistance values, and wherein a first resistance value of the plurality of MOS transistors is greater than a resistance value of the plurality of native transistors, and a second resistance value of the MOS transistors is less than the resistance value of the plurality of native transistors, and wherein parameter values of the plurality of native transistors are selected such that the plurality of native transistors function as a pull-up resistor;
- a driver circuit receiving an ESD protection signal from the RC trigger circuit;
- and
- a discharge transistor having a gate coupled to an output of the driver circuit.
4 more elements
Dependencies are inferred from the claim text.