High side current sense amplifier
US8648623B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Apr 16, 2012 |
| Grant date | Feb 11, 2014 |
| Priority date | — |
| Expiry date | May 5, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45548
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A single stage current sense amplifier is described that generates a differential output that is proportional to a current through a sense resistor. The voltage across the sense resistor is Vsense. The current sense amplifier includes a differential transconductance amplifier having high impedance input terminals. An on-chip RC filter filters transients in the Vsense signal. A feedback circuit for each leg of the amplifier causes a pair of input transistors to conduct a fixed constant current irrespective of Vsense, which stabilizes the transconductance. A gain control resistor (Re) is coupled across terminals of the pair of input transistors and has Vsense across it. The current through the gain control resistor is therefore Vsensex1/Re. A level shifting circuit coupled to each of the input transistors lowers a common mode voltage at an output of the amplifier. Chopper circuits at the input and output cancel any offset voltages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.