Current threshold detector
US4587442A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1983 |
| Grant date | May 6, 1986 |
| Priority date | — |
| Expiry date | Dec 1, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/343
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit for detecting a very large output current threshold with respect to a flow reference current. The threshold detector circuit includes a multiple transistor circuit wherein a pair of emitter areas are ratioed with respect to each other, and which have common bases, and an error amplifier the inputs of which are connected to the respective emitters of the multiple transistor circuit. An output current is sourced from the emitter of the multiple transistor circuit having the larger area which output current is a function of the load coupled therewith to thereby produce a voltage at this emitter the magnitude thereof being a function of the output current. The current sourced from the other emitter of the multiple transistor circuit to the additional input of the error amplifier is proportional to the bias current sourced therefrom by the error amplifier whereby the error amplifier effectfully monitors the emitter voltages of the multiple transistor circuit to provide an error signal the sense of which switches as the output load current varies above and below a threshold value that is a function of the magnitude of the reference current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.