Depletion controlled isolation stage
US5925922A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1993 |
| Grant date | Jul 20, 1999 |
| Priority date | — |
| Expiry date | Aug 19, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D89/711
Abstract
An input protection device is presented having a depletion controlled isolation stage. In one embodiment of the invention, a depletion controlled isolation resistor is formed between adjacent N+ diffused regions by N-well diffusion. One N+ diffused region electrically contacts an input bond pad and a primary protective device. The other N+ diffused region electrically contacts a second protective device and the internal circuit it is to protect. The depletion controlled isolation resistor limits the amount of current passing through the resistor to a safe level during an over-voltage condition. In another embodiment of the invention, a depletion controlled isolation stage includes a silicon controlled rectifier (SCR) as the primary protective device in combination with the depletion controlled isolation resistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.