Apparatus for using a well current source to effect a dynamic threshold voltage of a MOS transistor
US7863689B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 5, 2009 |
| Grant date | Jan 4, 2011 |
| Priority date | — |
| Expiry date | Jan 5, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D86/201
Abstract
Deep submicron wells of MOS transistors, implemented over an ungrounded well, exhibit two modes of operation: a current sink mode and a current source mode. While operation as a current sink is well understood and successfully controlled, it is also necessary to control the current provided in the current source mode of the well. A Schottky diode is connected between the well and the gate, the Schottky diode having a smaller barrier height than that of the PN junction of the well-to-source. For an NMOS transistor, current flows through the PN junction when the gate is high. When the gate is low, current flows through the Schottky diode. This difference of current flow results in a difference in transistor threshold, thereby achieving a dynamic threshold voltage using the current from the well when operating at the current source mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.