Accurate current sensing
US10234487B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2015 |
| Grant date | Mar 19, 2019 |
| Priority date | — |
| Expiry date | Sep 25, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/0054
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A current sense circuit for a pass transistor is described. The circuit comprises a sense transistor having input and control ports that are coupled to input and control ports respectively of the pass transistor. The circuit comprises a differential amplifier comprising a differential input and output. An output port of the pass transistor is coupled to a first port of the differential input and an output port of the sense transistor is coupled to a second port of the differential input. The differential amplifier comprises a first sub-amplifier and a second sub-amplifier that are arranged in parallel and which are operated in an auto-zero phase and in an amplification phase in an alternating manner, and which are operated in the auto-zero phase in a mutually exclusive manner. The output of the differential amplifier is used to control voltage drops across the sense transistor and the pass transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.