MOS threshold control circuit
US4791318A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1987 |
| Grant date | Dec 13, 1988 |
| Priority date | — |
| Expiry date | Dec 15, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/00384
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit for controlling the circuit thresholds on an MOS integrated circuit takes advantage of the fact that all MOS devices of a particular type on the same chip have nearly identical characteristics. The circuit thresholds are varied by applying a control voltage to the back gate of an MOS device in each stage to be controlled. The control voltage is generated in a reference stage which utilizes a feedback loop to servo the back gate voltage of an MOS transistor in the loop. A reference voltage equal to the desired circuit threshold votlage is applied to the input of the reference stage. The reference voltage and the reference stage output are applied to an amplifier in the feedback loop. The amplifier applies to the back gate of the MOS transistor in the reference stage a control voltage that tends to equalize or establish a desired offset between the reference voltage and the reference stage output. The control voltage applied to the reference stage back gate is coupled to the back gate of the MOS transistor in each operating stage. The threshold control circuit is particularly useful in CMOS circuits, but can be utilized in any MOS circuit having an MOS transistor with an ac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.