Dynamically biased output structure

An integrated circuit including a dynamically biased output structure of an amplifier, the dynamically biased output structure having a non-inverting input terminal for receiving a first input voltage, an inverting input terminal for receiving a second input voltage, and an output terminal for outputting an output voltage, comprising:

• a transconductance amplification stage, including:
• a differential pair of transistors, wherein a first input terminal of the amplification stage includes a control electrode of a first transistor of the differential pair, wherein a second input terminal of the amplification stage includes a control electrode of a second transistor of the differential pair, and wherein a current equal to a bias current flows through a conducting electrode of the first transistor and through a conducting electrode of the second transistor when a first input voltage at the first input terminal is equal to a second input voltage at the second input terminal,
• first circuitry, coupled to the conducting electrode of the first transistor and to a node, for providing a first current,
• second circuitry, coupled to the node, for sinking a second current from the node, wherein the second current is equal to the first current minus the bias current during operation,
• tail current boosting circuitry, coupled to the node, for providing a translinear expansion of tail current of the differential pair, the tail current responsive to a voltage at the node, and
• a feedback loop that dynamically biases the differential pair by controlling the voltage at the node by negative feedback,
• wherein the current through the conducting electrode of the second transistor is maintained at a constant value, and wherein a conducting electrode of the first transistor provides a current responsive to a difference between the first input voltage and the second input voltage;
• and
• a current mirror, coupled to the transconductance amplification stage, for providing an output current at the output terminal of the output structure, wherein the output current is equal in magnitude to the current of the first conducting electrode of the second transistor.

An amplifier having at least an output terminal, comprising:

• output circuitry having at least one input terminal for receiving an input voltage, and an output terminal coupled to the output terminal of the amplifier for outputting an output voltage, the output circuitry comprising:
• a transconductance amplification stage, including:
• a differential pair of transistors, wherein a first input terminal of the amplification stage includes a control electrode of a first transistor of the differential pair, wherein a second input terminal of the amplification stage includes a control electrode of a second transistor of the differential pair,
• first circuitry, coupled to a conducting electrode of the first transistor and to a node, for providing a first current,
• second circuitry, coupled to the node, for sinking a second current from the node, wherein the second current is equal to the first current minus a bias current of the differential pair during operation,
• tail current boosting circuitry, coupled to the node, for providing a translinear expansion of a tail current of the differential pair, the tail current responsive to a voltage at the node;
• and
• a feedback loop that dynamically biases the differential pair by controlling the voltage at the node by negative feedback,
• wherein a current through a conducting electrode of the second transistor is maintained at a constant value, and wherein a conducting electrode of the first transistor provides a current responsive to a difference between a voltage at the first input terminal and a voltage at the second input terminal;
• and
• a current mirror, coupled to the transconductance amplification stage, for providing an output current at the output terminal of the output circuitry, wherein the output current has a magnitude that is equal to or greater than a magnitude of the current through the first conducting electrode of the second transistor;
• and
• other circuitry for providing the input voltage to the input terminal of the output circuitry, wherein the output circuitry acts as a buffer between the other circuitry and the output terminal of the amplifier.