High side current sense amplifier
US5627494A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 1995 |
| Grant date | May 6, 1997 |
| Priority date | — |
| Expiry date | Dec 4, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/343
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A high side current sense amplifier (21) comprises a first resistor, a second resistor, an amplifier (22), and a darlington transistor pair. The first resistor has a first input and a second input coupled to a non-inverting input of the amplifier (22). The darlington transistor pair has a collector coupled to the non-inverting input of the amplifier (22), a base coupled to an output of amplifier (22), an emitter. The second resistor is coupled between the emitter of the darlington transistor pair and ground. A differential voltage is applied across the first input of the first resistor and an inverting input of the amplifier (22). The darlington transistor pair converts an output voltage of the amplifier (22) to a feedback current for generating a voltage across the first resistor. Under stable conditions the voltage across the first resistor is equal to the differential voltage. The voltage gain is the ratio of the second resistor to the first resistor. The high side current sense amplifier (21) has excellent common mode voltage rejection and minimizes common mode error due to semiconductor wafer process variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.