High accuracy low temperature drift high-side current sensing hardware and method
US11175319B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2020 |
| Grant date | Nov 16, 2021 |
| Priority date | — |
| Expiry date | Sep 18, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0012
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A wireless-power-transmission-system includes a bridge with a tank-capacitor coupled thereto, a sense-resistor coupled between the bridge and an input of a regulator, a switching-circuit having first and second inputs coupled across the sense-resistor, and a gain-stage having first and second inputs capacitively coupled to first and second outputs of the switching-circuit. An ADC digitizes output of the gain-stage by comparing the output to a reference voltage, and a temperature-independent current source is coupled to a reference-resistor to generate the reference voltage. In a reset-phase, the switching-circuit shorts the inputs of the gain-stage to one another, and the gain-stage shorts its inputs to its output. The switching-circuit, in a first-chopping-phase, couples the sense-resistor between the first and second inputs of the gain-stage, and in a second-chopping-phase, couples the sense-resistor in reverse between the second and first inputs of the gain-stage. The resistance of the reference-resistor tracks the sense-resistor across temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.