Breakdown protection circuit using high voltage detection
US5493244A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 1994 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | Jan 13, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A high voltage circuit includes a first switching device for supplying one of a high voltage (V.sub.pp) and a low voltage (V.sub.cc) to a controlled path that includes a series connection of a control p-channel transistor and a protection p-channel transistor. A high voltage detector is utilized to determine whether V.sub.pp or V.sub.cc is applied to the controlled path. The high voltage detector also establishes a protecting condition for the protection p-channel transistor during V.sub.pp operation. On the other hand, the detector establishes a non-protecting condition during V.sub.cc operation, thereby rendering the protecting p-channel transistor transparent to circuit performance. A signal input switches the control p-channel transistor between on and off states. When the control transistor is in an off state and the protection transistor is in a protecting condition, the voltage drop along the controlled path will cause the protection transistor to turn off, so as to limit the voltage across the control transistor. A second controlled path is preferably in series connection with the first controlled path. The second controlled path includes n-channel transistors, with one of …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.