High breakdown-voltage transistor with transient protection
US6169309A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 1998 |
| Grant date | Jan 2, 2001 |
| Priority date | — |
| Expiry date | Sep 24, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/516
Abstract
A circuit for protecting a transistor against electrical transients. The circuit comprises a first diode coupled between a first terminal coupled to a power supply and a control terminal of the protected transistor. The circuit also comprises a second diode and a resistor coupling the control terminal of the protected transistor to a reference potential. A second transistor is coupled in shunt to the protected transistor. The voltage on the control terminal of the second transistor is determined by the current through the resistor. The embodiments may be implemented in an integrated circuit wherein the second, shunting transistor is formed from parasitic elements within the semiconductor body in which the protected transistor is formed. In one embodiment, the protected MOS transistor is formed in an n-well 504 and a shunting bipolar transistor is formed between the n-well 504 and an n-doped guard ring 500 formed adjacent to the n-well in the p-doped substrate 508.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.