Temperature stabilized constant fraction voltage controlled current source
US5672961A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1995 |
| Grant date | Sep 30, 1997 |
| Priority date | — |
| Expiry date | Dec 29, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/225
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A current source includes a control stage responsive to a stable, d.c. input voltage that is operative to produce a control voltage proportional to absolute temperature (PTAT), and an output stage responsive to the PTAT control voltage that is operative to produce an output current that is an essentially constant fraction of an output constant current source. The control stage includes a temperature-dependent control resistor of a given resistor type, and at least one control constant current source providing the control resistor with a temperature dependent control current. The temperature dependent current source includes a temperature dependent current source resistor based on the given resistor type such that the temperature dependencies of the control current and the control resistor tend to cancel in such a manner that a true PTAT control voltage is developed. The output stage includes an output transistor coupled to an output constant current source such that an output current of the output stage has no current contribution other than from the output current source. A method for providing a current that is a constant fraction of an output constant current source includes the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.