Low-consumption voltage regulator

A circuit, comprising:

• an AB class operational amplifier having an inverting input, a non-inverting input, an output, and a non-drivable input coupled to an input voltage, the AB class operational amplifier comprising a first AB amplifier cell and a second AB amplifier cell;
• a power transistor having a gate terminal coupled to the output terminal of the operational amplifier, a source terminal coupled to the input voltage, and a drain terminal coupled to an output terminal of the regulator;
• a voltage divider having an input coupled to the drain terminal of the power transistor and an output coupled to the non-inverting input of the AB class amplifier;
• and
• the inverting input of the AB class amplifier coupled to a first reference voltage, the AB class amplifier adapted to amplify a voltage difference between the further reference voltage and the output of the voltage divider.

A voltage regulator circuit, comprising:

• a power transistor having a source terminal coupled to a voltage input, a drain terminal coupled to an output terminal, and a control terminal;
• a voltage divider having a first terminal coupled to the source terminal of the power transistor, a second terminal coupled to a ground reference potential, and an output terminal;
• and
• an AB class amplifier having an output coupled to the control terminal of the power transistor, a non-drivable terminal coupled to the input voltage, a non-inverting input coupled to the output terminal of the voltage divider, and an inverting input coupled to a reference voltage source, the AB class amplifier comprising a cascode mirror, a first amplifier cell comprising a first differential pair, a second amplifier cell comprising a second differential pair, and each amplifier cell comprising an output coupled to the cascode mirror and to a drivable terminal of a respective further transistor, the AB class amplifier adapted to amplify a voltage difference between the reference voltage and the output of the voltage divider.

A circuit, comprising:

• an AB class operational amplifier having an inverting input, a non-inverting input, an output, and a non-drivable input coupled to an input voltage, the AB class operational amplifier comprising a first AB amplifier cell and a second AB amplifier cell, each AB amplifier cell comprising a differential pair of transistors having a pair of input terminals connected in phase opposition, and each amplifier cell comprising an output terminal coupled to a common terminal of the respective differential pair of transistors, the output of each AB amplifier cell connected to the drivable terminal of a respective further transistor, each farther transistor having a non-drivable terminal connected to the common terminal of the differential pair;
• a power transistor having a gate terminal coupled to the output terminal of the operational amplifier, a source terminal coupled to the input voltage, and a drain terminal;
• a voltage divider having an input coupled to the drain terminal of the power transistor and an output coupled to the non-inverting input of the AB class amplifier;
• and
• the inverting input of the AB class amplifier coupled to a first reference voltage, the AB class amplifier adapted to amplify a voltage difference between the further reference voltage and the output of the voltage divider.