Patent · US Expired

Series voltage regulator with limited current consumption at low input voltages

US4731574A · kind A · utility

70Cited by
5References
21Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 20, 1987
Grant dateMar 15, 1988
Priority date
Expiry dateMay 20, 2007

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S323/908
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A series voltage regulator having a regulating transistor (T.sub.1) arranged with its emitter-to-collector path in a series arm of the regulator, the base of which is controlled via a control transistor (T.sub.2) by a first differential amplifier (V) which compares a reference voltage (U.sub.REF) with a voltage proportional to the voltage (U.sub.2) of the regulator output. A differential circuit (V.sub.2) which compares the collector-to-emitter voltage of the regulating transistor (T.sub.1) with an auxiliary voltage (U.sub.3) is provided, the output of which is followed by a current limiting circuit (T.sub.3) which acts upon control transistor (T.sub.2). The auxiliary voltage (U.sub.3) is larger than the collector-to-emitter voltage of the regulating transistor (T.sub.1) which occurs at the beginning of the saturation state of the regulating transistor. The current limiting circuit (T.sub.3) limits the current delivered by the control transistor (T.sub.2) to the base of the regulating transistor (T.sub.1) as soon as the differential circuit (V.sub.2) detects a drop in the collector-to-emitter voltage of the regulating transistor (T.sub.1) to the auxiliary voltage (U.sub.3). The aux…

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