Current source having a wide range of output voltages
US4901002A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 23, 1989 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Feb 23, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F1/595
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A current source having a wide range of output voltages. The emitter-collector path of a main transistor (T.sub.30) of the npn type, arranged to define the value of the current, is connected in series with the collector-emitter paths of a plurality of cascaded npn-type output transistors (T.sub.31 . . . T.sub.35). Each output transistor (T.sub.31 . . . T.sub.35) is associated with a respective control transistor (T'.sub.31 . . . T'.sub.35) of the opposite type. At least some of the control transistors have their emitters connected to respective collectors of output transistors of a different rank. This yields an output voltage V.sub.s which can range between small values and a value close to the supply voltage V.sub.c.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.