Low voltage bias circuit
US4833344A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 1987 |
| Grant date | May 23, 1989 |
| Priority date | — |
| Expiry date | Feb 5, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/30
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A bias circuit (FIG. 5) of the type comprising a bias transistor (T1) having a pair of resistors (R1, R2) in its collector path, the junction of these two resistors (R1 and R2) being connected to the transistor base. The base of a drive transistor (T2), of like polarity type, is connected to the collector of the bias transistor (T1), this serving as current source or sink. To provide and increase extended operation, operation at supply voltages lower than usual and current regulation from low supply voltage (0.9V) to much high voltage, this circuit is modified by the provision of a third resistor (R3) in the collector path and a diode shunt (T3) between the base of the drive transistor T2 and the junction of the third and first resistors (R3 and R1). The polarity inverse of this modified circuit is also effective and may be combined, in cascade or in ring feedback loop configuration, with the aforementioned modified circuit. These latter combinations serve to provide yet higher order current regulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.