Voltage regulator circuit with adaptive current limit and method for operating the voltage regulator circuit

摘要

A voltage regulator circuit and a method for operating the voltage regulator circuit are described. In one embodiment, a voltage regulator circuit includes an input terminal to receive an input signal from a power interface, an output terminal to output an output signal using the input signal, an output voltage monitor circuit configured to compare the voltage of the output signal with a predetermined voltage threshold, and a current limit circuit configured to limit current flowing on a path from the input terminal to the output terminal to a transient current limit level. The transient current limit level is lower than a predefined current limit threshold of the power interface. Other embodiments are also described.

主权项

1. A voltage regulator circuit comprising:
an input terminal to receive an input signal from a power interface; an output terminal to output an output signal using the input signal; an output voltage monitor circuit configured to compare an output voltage of the output signal with a predetermined voltage threshold; and a current limit circuit configured to limit current flowing on a path from the input terminal to the output terminal to a transient current limit level, wherein the transient current limit level is lower than a predefined current limit threshold of the power interface, wherein the current limit circuit is further configured to increase the transient current limit level if the output voltage is higher than the predetermined voltage threshold, and wherein the current limit circuit includes a first current source that is enabled during the startup of the voltage regulator circuit and a second current source that is enabled after the output voltage is higher than the predetermined voltage threshold, wherein the current limit circuit comprises a replica bias circuit configured to generate a replica of a voltage transformed from the input signal onto an output capacitor connected to the output terminal and a current mirror circuit that is connected between the input terminal and the output terminal, and wherein the current mirror circuit includes two transistor devices, the first and second current sources, a switch circuit connected in series with the second current source and a control circuit configured to enable or disable the switch circuit to connect or disconnect the second current source.