Differential or single-ended amplifier and relative control method
AssigneeSTMicroelectronics S.r.l.
InventorPhilippe Sirito-Olivier
Life of this patent
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Abstract
The method controls, in a feedback mode, a common collector or common drain amplifier, biased with a voltage applied on a bias node produced by a biasing circuit that generates a temperature compensated reference voltage from which the bias voltage applied on the bias node of the amplifier is derived. The quiescent voltage on the output node of the amplifier is made substantially independent from temperature by sensing the quiescent voltage on the output node, and adjusting the voltage applied on the bias node of the amplifier based upon the difference between the reference voltage and the sensed quiescent voltage for maintaining it constant.
Claims17
A method of controlling, in a feedback mode, a common-terminal amplifier biased with a bias voltage applied to a control node thereof and generating an output signal proportional to an input signal, with a quiescent voltage on an output node thereof;
- a biasing circuit including a voltage generator of a temperature independent reference voltage producing the bias voltage applied on the control node of the amplifier, the method comprising:
- sensing the quiescent voltage of the amplifier;
- and
- adjusting the bias voltage applied to the control node of the amplifier based upon a difference between the temperature independent reference voltage and the sensed quiescent voltage to maintain the quiescent voltage constant.
A method of controlling a common-terminal amplifier in a feedback mode comprising:
- biasing a control node of the amplifier with a bias voltage generated with a temperature independent reference voltage;
- generating an output signal, proportional to an input signal, with a quiescent voltage on an output node of the amplifier;
- sensing the quiescent voltage of the amplifiers;
- and
- adjusting the bias voltage applied to the control node of the amplifier based upon a difference between the temperature independent reference voltage and the sensed quiescent voltage to maintain the quiescent voltage constant.
A common-terminal amplifier circuit generating an output signal proportional to an input signal and with a DC component, comprising:
- a common-terminal amplifier having a control node;
- a biasing circuit including a voltage generator to generate a temperature independent reference voltage;
- and
- a feedback circuit comprising
- a sensing circuit for sensing the DC component of the output signal, and
- an operational amplifier outputting a bias voltage applied to the control node of the common-terminal amplifier based upon a difference between the reference voltage and the sensed DC component of the output signal.
A common-terminal differential amplifier circuit comprising:
- a pair of common-terminal single-ended amplifiers each biased with a bias voltage applied on respective control nodes, and generating a differential output signal proportional to a differential input signal with a common mode output voltage;
- a biasing circuit including a voltage generator to generate a temperature independent reference voltage for producing the bias voltage applied to the control nodes of the common-terminal amplifiers;
- and
- a feedback circuit comprising
- a sensing circuit connected to the outputs of the amplifiers to sense the common mode output voltage, and
- an operational amplifier outputting a bias voltage applied to the control nodes of the common-terminal amplifiers based upon a difference between the reference voltage and the sensed common mode output voltage.
Dependencies are inferred from the claim text.