Temperature compensated circuit for controlling load current
US5237262A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1991 |
| Grant date | Aug 17, 1993 |
| Priority date | — |
| Expiry date | Oct 24, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/907
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A temperature compensated control circuit includes a load transistor which passes the load current and has an on-resistance which varies with temperature. To provide temperature compensation, first and second pilot transistors are integrated with the load transistor such that as the load transistor heats-up due to the load current passing through the on-resistance of the load transistor, the first and second pilot transistors heat-up due to heat conduction from the load transistor. Each of the pilot transistors has an on-resistance which varies proportionally or similarly to the on-resistance of the load transistor. A first current source supplies a first level of current to the on-resistance of the first pilot transistor to develop a first reference voltage, and a second current source supplies a second level of current to the on-resistance of the second pilot transistor to develop a second reference voltage. The range between the first and second reference voltages corresponds to an acceptable range of load current. A voltage corresponding to the load current is sensed across the load transistor, and the control circuit controls the load current to maintain the sensed voltage wit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.