Regulator with low dropout voltage and improved output stage
AssigneeSTMicroelectronics (Rousset) SAS
InventorsJimmy Fort, Thierry Soude
Life of this patent
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Abstract
The regulator with low dropout voltage comprises an error amplifier and an output stage comprising an output transistor and a buffer circuit comprising an input connected to the output node of the error amplifier, an output connected to the output transistor, a follower amplifier connected between the input and the output of the buffer circuit. The buffer circuit furthermore comprises a transistor active load connected to the output of the follower amplifier and a negative feedback amplifier arranged in common gate configuration and connected between the output of the follower amplifier and the gate of the transistor of the active load.
Claims20
A regulator with low dropout voltage, comprising an error amplifier and an output stage comprising:
- an output transistor;
- and
- a buffer circuit comprising:
- an input connected to an output node of the error amplifier,
- an output connected to the output transistor, a follower amplifier connected between the input and the output of the buffer circuit, characterized in that the buffer circuit furthermore comprises:
- a transistor active load connected to an output of the follower amplifier;
- and
- a negative feedback amplifier arranged in common gate configuration and connected between the output of the follower amplifier and the gate of the transistor of the active load.
An integrated circuit, comprising:
- a power supply terminal;
- a ground terminal;
- a regulator connected between the power supply terminal and the ground terminal and including:
- an error amplifier and an output stage comprising:
- an output transistor;
- and
- a buffer circuit comprising:
- an input connected to an output node of the error amplifier,
- an output connected to the output transistor, a follower amplifier connected between the input and the output of the buffer circuit, characterized in that the buffer circuit furthermore comprises:
- a transistor active load connected to an output of the follower amplifier;
- and
- a negative feedback amplifier arranged in common gate configuration and connected between the output of the follower amplifier and the gate of the transistor of the active load;
- and
- a load coupled to an output of the regulator.
A regulator circuit comprising:
- an error amplifier having a first output;
- a buffer circuit having a first input connected to the first output and having a second output;
- an output stage having a second input connected to the second output and having a third output;
- wherein the buffer circuit includes:
- a follower amplifier coupling the first input and the second output,
- a transistor active load connected to an output of the follower amplifier and having a gate terminal, and
- a common gate mode negative feedback amplifier connected between the third output and the gate terminal
Dependencies are inferred from the claim text.