Patent · US Expired

Current reference for feedback current source

US4739246A · kind A · utility

7Cited by
5References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 1, 1987
Grant dateApr 19, 1988
Priority date
Expiry dateJun 1, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05F3/265
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A Current Reference for providing a feedback signal to a current driver in a current-series, feedback-controlled current source circuit that includes at least one, but more likely more than one, controlled current source. The Current Reference comprises a current mirror having an input transistor coupled to an output transistor in a current mirror configuration. The input transistor of the current mirror is driven by a constant current source, Icc, so that the current mirror output transistor causes a current substantially equal to Icc to flow out of a summing node. A sensing transistor is coupled to a controlled current source for providing a current into the summing node that is representative of the current delivered by the controlled current source. As a result, the current flowing away from the summing node and into a phase inverter is representative of the difference between the delivered current and Icc. The output of the phase inverter is coupled to the current driver so as to maintain the magnitude of the delivered current at the intended value.

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