High side current monitor with extended voltage range
US6956727B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 21, 2004 |
| Grant date | Oct 18, 2005 |
| Priority date | — |
| Expiry date | Apr 10, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/0092
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A high side current monitor circuit includes an op amp which is coupled across a sensing element which carries a current Isense and develops a shunt voltage Vsense. A feedback transistor driven by the op amp output conducts an output current Iout through a resistor to a current output node necessary to make the op amp inputs equal, such that Iout is proportional to Isense. Iout is conducted through a resistor to generate a ground-referred voltage proportional to Vsense. When the common mode voltage of Vsense is greater than the op amp's breakdown voltage, a discrete transistor is connected between the current output node and ground to stand off the voltage across the amp. The monitor circuit is arranged such that it can be powered with a limited fraction of the common mode voltage when used with a discrete transistor, and is self-biased when used without a discrete transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.