ESD protection using diode-isolated gate-grounded NMOS with diode string
An ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device. A method of forming an ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device.
1. An integrated circuit, comprising:
a gate-grounded NMOS ESD device with diode-isolation having an isolation diode in series with a source of a gate-grounded NMOS transistor, where said isolation diode is segmented and placed in close proximity to, and on opposite sides of, a body of said gate-grounded NMOS ESD device; and
a diode string coupled to said gate-grounded NMOS ESD device in a forward biased configuration, where diodes of said diode string are segmented and surround said body of said gate-grounded NMOS ESD device.
2. The integrated circuit of claim 1 where said diode string is composed of between 2 and 4 diodes.
3. The integrated circuit of claim 1 where said diode string is composed of 3 diodes.
4. The integrated circuit of claim 1 where said diode string is electrically coupled in series with said diode-isolation and in parallel with said gate-grounded NMOS ESD device.
5. The integrated circuit of claim 1 where said diode string is electrically coupled in parallel with said gate-grounded NMOS ESD device and in parallel with said diode-isolation.
6. The integrated circuit of claim 1 where a gate of said gate-grounded NMOS ESD device is coupled to ground through a resistor.
7. The integrated circuit of claim 1 where said diode string is composed of a gated diode string.
8. The integrated circuit of claim 1 where a substrate contact diffusion surrounds said diodes and said gate-grounded NMOS ESD device.
9. The integrated circuit of claim 1 where said gate-grounded NMOS ESD device, is a core NMOS transistor, an I/O NMOS transistor, or a drain extended NMOS transistor.