Voltage Regulator and Method for Voltage Regulation

A voltage regulator, comprising:

• an input terminal;
• an output terminal at which an output voltage is provided;
• an output transistor which couples the input terminal of the voltage regulator to the output terminal of the voltage regulator;
• and
• a transimpedance amplifier including
• an input terminal which is coupled to the output terminal of the voltage regulator and
• an output terminal which is coupled to a control terminal of the output transistor via a coupling, the coupling having an impedance value between the output terminal of the transimpedance amplifier and the control terminal of the output transistor which at a given frequency is smaller than or equal to an impedance value of an output impedance of the transimpedance amplifier,
• wherein the transimpedance amplifier comprises an amplifier including
• an input terminal which is coupled to the input terminal of the transimpedance amplifier, and
• an output terminal which is coupled to the output terminal of the transimpedance amplifier, and
• wherein the transimpedance amplifier further comprises a first impedance which couples the output terminal of the transimpedance amplifier to the input terminal of the transimpedance amplifier and which comprises
• a first resistor with a first terminal which is connected to a first terminal of the first impedance,
• a second resistor with a first terminal which is connected to a second terminal of the first resistor and a second terminal which is connected to the second terminal of the first impedance and
• a first capacitor which couples the second terminal of the first resistor to the input terminal of the voltage regulator.

A method for voltage regulation, comprising the steps of:

• supplying an input voltage to an output transistor which provides an output voltage;
• providing a feedback current which depends on the output voltage;
• and
• providing a control voltage by a transimpedance amplifier depending on the feedback current, wherein the control voltage is provided to a control terminal of the output transistor via a coupling, the coupling having an impedance value between the output terminal of the transimpedance amplifier and the control terminal of the output transistor which at a given frequency is smaller than or equal to an impedance value of the output impedance of the transimpedance amplifier, and wherein the feedback current is provided to the input terminal of the transimpedance amplifier, wherein the transimpedance amplifier comprises:
• an amplifier with an input terminal that is coupled to the input terminal of the transimpedance amplifier and with an output terminal that is coupled to the output terminal of the transimpedance amplifier, and
• a first impedance which couples the output terminal of the transimpedance amplifier to the input terminal of the transimpedance amplifier and which comprises
• a first and a second resistor that are connected in series between the input terminal and the output terminal of the transimpedance amplifier, and
• a first capacitor, wherein a node between the first resistor and the second resistor is coupled to the input terminal via the first capacitor.

A voltage regulator, comprising:

• an input terminal;
• an output terminal at which an output voltage is provided;
• an output transistor which couples the input terminal of the voltage regulator to the output terminal of the voltage regulator;
• and
• a transimpedance amplifier including
• an input terminal which is coupled to the output terminal of the voltage regulator and
• an output terminal which is coupled to a control terminal of the output transistor,
• wherein the transimpedance amplifier comprises an amplifier including
• an input terminal which is coupled to the input terminal of the transimpedance amplifier, and
• an output terminal which is coupled to the output terminal of the transimpedance amplifier, and
• wherein the transimpedance amplifier further comprises a first impedance which couples the output terminal of the transimpedance amplifier to the input terminal of the transimpedance amplifier and which comprises
• a first resistor with a first terminal which is connected to a first terminal of the first impedance,
• a second resistor with a first terminal which is connected to a second terminal of the first resistor and a second terminal which is connected to the second terminal of the first impedance and
• a first capacitor which couples the second terminal of the first resistor to the input terminal of the voltage regulator.