Trimming method of DCR sensing circuits
US10650946B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 2018 |
| Grant date | May 12, 2020 |
| Priority date | — |
| Expiry date | Aug 24, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/158
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit and method provide improved trimming of a DCR sensing circuit where a sensing element is sensitive to self-heating or having a large tolerance. The circuit includes a resistive divider circuit coupled to a sensing element. The resistive divider circuit includes a trim resistor and two test points. Prior to trimming the trim resistor, an actual resistance of the sensing element is determined. A target voltage across the trim resistor to be trimmed is calculated according to the determined sensing element resistance and a known small trim current that is to be injected into the circuit during the trimming process. This injected trim current has a low current value so there is no self-heating of the sensing element. Then, the trim resistor is trimmed while injecting this small trim current into the resistive divider circuit and the voltage across the trim resistor is monitored.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.