Patent · US Expired

Exponential function circuitry

US5065053A · kind A · utility

7Cited by
9References
33Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 26, 1990
Grant dateNov 12, 1991
Priority date
Expiry dateFeb 26, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06G7/24
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Circuitry and method for generating electrical currents representative of an exponential function of an input current. The circuit includes an input diode chain and an output diode chain. Each of the diodes in the input diode chain has an input current passing therethrough. The input current is produced by an input current source connected in sources with the diode below the cathode of the diode. A voltage driving circuit drives a voltage drop across the output diode chain that has a predetermined relationship to the voltage drop across the input diode chain. The voltage drop across the output diode chain results in a current through the output diode chain. The number of diodes in the output diode chain is preselected relative to the number of diodes in the input diode chain such that the current through the output diode chain is representative of an exponential function of the input current or currents.

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