Circuit for generating reference voltages and reference currents
US4970415A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1989 |
| Grant date | Nov 13, 1990 |
| Priority date | — |
| Expiry date | Jul 18, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/907
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In one embodiment, a semiconductor device which generates a substantially constant reference voltage over a broad temperature range upon application of a power supply voltage thereto, wherein a current substantially inversely proportional to the value of a load resistor is drawn through the resistor to generate a substantially constant voltage across the resistor. The current through the resistor is the sum of a first current and a second current. The first current is determined by the absolute value of the threshold voltage of a depletion mode FET (DFET) in conjunction with an associated first resistor. The second current is determined by the threshold voltage of an enhancement mode FET (EFET) in conjunction with an associated second resistor. As the temperature of the device changes the first and second currents will change in opposite directions with the sum being changed inversely proportional to the change in resistance with temperature of the load resistor. As a result, the voltage across the load resistor will remain substantially constant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.