Input/output protection device for use in semiconductor device
US5717559A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 26, 1996 |
| Grant date | Feb 10, 1998 |
| Priority date | — |
| Expiry date | Jul 26, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D89/911
Abstract
An input/output protection device for protecting an internal circuit of an integrated circuit formed on a P-type substrate, from an electrostatic discharge (ESD), includes a thyristor connected between a terminal connected to the internal circuit and a common wiring conductor. The protection device comprises a N-well formed in the P-type substrate, a first P-type diffused region formed in the N-well and connected to the terminal, a first N-diffused region formed to adjoin the first N-well, a second P-type diffused region formed in close proximity to the first N-type diffused region, and a second N-type diffused region formed in the P-type substrate and connected to the common wiring conductor. An external resistor is connected between the first P-type diffused region and the first N-type diffused region, and another external resistor is connected between the second P-type diffused region and the second N-type diffused region. A diode is constituted of the first N-diffused region and the second P-type diffused region in close proximity to each other, so that the diode has a low parasitic resistance. Thus, when a negative electrostatic pulse is applied to the terminal, the diode allo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.