Transistor constant bias circuits
US4763018A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 5, 1987 |
| Grant date | Aug 9, 1988 |
| Priority date | — |
| Expiry date | Feb 5, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/30
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A circuit (FIG. 4) in which a sub-circuit comprised of a bias transistor (T1), a feedback reisistor (R2) connected between the collector of this transistor (T1) and its base, and, a drive transistor (T2), is connected to its polarity-inverse sub-circuit (T1', R2', T2') in a ring configuration and is initiated by means of current injection from a start-up bias circuit. The latter may comprise a bias transistor (T1"), a drive transistor (T2") the base of which is connected to the collector of the bias transistor (T1"), and a pair of feedback current/voltage divider resistors (R1", R2") in the collector path of the bias transistor (T1"). Following start-up, constant current is maintained by feedback in the ring, and this current may be tapped at an appropriate point in the ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.