Patent · US Expired

Voltage level detecting circuit

US4424457A · kind A · utility

4Cited by
3References
17Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 20, 1981
Grant dateJan 3, 1984
Priority date
Expiry dateMay 20, 2001

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG04C10/04
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A voltage level detector circuit, which enables an input voltage to be compared with a predetermined stable reference level, defined on the basis of the sum of a first value of the direct voltage across the terminals of a diode and of the product of the difference between this first value and a second value of the voltage across the terminals of the diode by a predetermined coefficient, comprises substantially identical bipolar transistors (1, 2), connected as diodes, in series with current sources (3, 4) for generating voltages representative of these first and second values, a capacitive calculating circuit (5-8) which produces a signal representative of the algebraic value of the difference between the input voltage and the reference level and an amplifier (9) for bringing this signal to a logic level.

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