Patent · US Expired

Current threshold detector circuit

US5057709A · kind A · utility

5Cited by
1References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 1, 1990
Grant dateOct 15, 1991
Priority date
Expiry dateNov 1, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K5/1534
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A dectector circuit responsive to a current suppled to an input thereof provides an output signal when the magnitude of the current exceeds a predetermined threshold level includes a multi-collector transistor having a first one of its collectors connected to the base thereof and an emitter coupled to the input. A diode formed by a diode-connected transistor is coupled to the first collector of the multi-collector transistor. A second transistor is provided having its collector coupled to the second collector of the multi-collector transistor, a base coupled to the first collector and an emitter which is coupled to a pair of series connected resistors. The second transistor is operated at a lower current density than the diode-connected transistor such that the former operates in a saturated condition until such time that the input current exceeds the threshold level to produce the output signal.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.