Quiescent Current Limitation for a Low-Dropout Regulator in Dropout Condition

摘要

An low dropout regulator and method that has reduced quiescent current consumption is presented. The voltage regulator circuit comprises an output terminal, a first circuit branch connected between an input voltage level and the output terminal, a second circuit branch connected between the input voltage level and a predetermined voltage level, a first current mirror for mirroring a current flowing in the second circuit branch to the first circuit branch, a first feedback circuit to regulate the output voltage, and a second feedback circuit for controlling the second switching element. The second feedback circuit comprises a current sensing means for sensing a current that depends on a current flowing in the first circuit branch and to control the second switching element such that the current flowing through the second circuit branch is limited to a current that depends on the current sensed by the current sensing means.

主权项

1. A voltage regulator circuit for outputting a regulated output voltage, comprising
an output terminal for outputting the output voltage; a first circuit branch connected between an input voltage level and the output terminal; a second circuit branch connected between the input voltage level and a predetermined voltage level, the second circuit branch comprising a first switching element and a second switching element connected in series; a first current mirror for mirroring a current flowing in the second circuit branch to the first circuit branch; a first feedback circuit for controlling the first switching element in dependence on the output voltage to thereby regulate the output voltage; and a second feedback circuit for controlling the second switching element, wherein the second feedback circuit comprises a current sensing means for sensing a current that depends on a current flowing in the first circuit branch; and the second feedback circuit is configured to control the second switching element such that the current flowing through the second circuit branch is limited to a current that depends on the current sensed by the current sensing means.