Circuit arrangement for producing a D.C. current

Abstract

A circuit arrangement (16) for producing a D.C. current, includes a feedback loop for producing a reference current from an output terminal (27) with a negative temperature coefficient. The feedback loop includes a current-source stage (17, 18) which feeds a current mirror stage (19, 20, 21) in response to a measuring current supplied from a current bank (24, 25, 28, 29), which also produces the output reference current. The output of the current mirror stage (19, 20, 21) drives a working impedance formed by the main current path of a transistor 22, across which a control voltage is developed which is applied to a control input (23) of the current bank (24, 25, 28, 29). The circuit arrangement is advantageously combined with a reference current source (1) arranged as a bandgap circuit for producing a reference current on an output terminal (2) with a positive temperature coefficient, by enabling the user to select a current reference with either a positive or negative temperature coefficient. Further, the respective reference current outputs with positive and negative temperature coefficients, properly dimensioned, may be combined to provide an output current from a common output terminal (35) which is independent of temperature in a predefined temperature range.

Dependencies are inferred from the claim text.