Patent ID: 11886214
Assignee: STMICROELECTRONICS S.R.L.
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A low-dropout voltage regulation device, comprising:
a power stage having an output terminal configured to be coupled to a load circuit, the load circuit being operable in a plurality of operating modes, the load circuit being configured to receive a different respective output current when in each of the plurality of operating modes;
an error amplifier having an output coupled to an input terminal of the power stage; and
a compensation circuit coupled to the input terminal of the power stage, wherein the compensation circuit is operable in a plurality of selectable configurations that are respectively tailored to the plurality of operating modes, the plurality of selectable configurations being selectable in response to a control signal representative of a current operating mode of the load circuit;
wherein the plurality of operating modes of the load circuit include a first operating mode in which the load circuit is intended to receive a first output current and a second operating mode in which the load circuit is intended to receive a second output current;
wherein the plurality of selectable configurations of the compensation circuit include a first configuration tailored to the first operating mode of the load circuit and a second configuration tailored to the second operating mode of the load circuit;
wherein in the first configuration, the compensation circuit is configured to attenuate variations in voltage at the output terminal of the power stage that occur upon a change from the second operating mode to the first operating mode, and to precharge an initial compensation voltage able to be usable upon change from the first operating mode to the second operating mode;
wherein in the second configuration, the compensation circuit is configured to apply the initial compensation voltage to the input terminal of the power stage upon the change from the first operating mode to the second operating mode;
wherein the compensation circuit comprises:
a first compensation stage including a compensation resistor and a first compensation capacitor that are coupled in series between the input terminal of the power stage and ground, the first compensation capacitor having a capacitance value that smooths variations in the voltage at the output terminal of the power stage that occur upon the change from the second operating mode to the first operating mode; and
a second compensation stage comprising at least one second compensation capacitor and being configured:
in the first configuration, to be electrically disconnected from the input terminal of the power stage at all times when operating in the first configuration and to charge the at least one second compensation capacitor so as to precharge the initial compensation voltage, and
in the second configuration, to be electrically coupled to the input terminal of the power stage and deliver, to the input terminal, the initial compensation voltage;

wherein the power stage includes a power transistor having a gate is coupled to the input terminal of the power stage;
wherein the error amplifier includes a first input coupled to a reference voltage and a second input coupled to a conduction terminal of the power transistor, and the precharged initial compensation voltage is approximately a sum of the reference voltage and a threshold voltage of the power transistor;
wherein the power transistor of the power stage is an n-channel power transistor, and wherein the conduction terminal to which the second input of the error amplifier is coupled comprises a source of the n-channel power transistor.