Amplifier with current mirror bias adjust
OwnerJames Pearce Hamleyinventor
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Abstract
An amplifier includes a differential amplifier stage, a voltage amplification stage and a power output stage. The bias level of the output stage is proportional to current through the voltage amplification stage. The voltage amplification stage includes a current mirror whereby controlled current through a first leg of the current mirror controls current through the remaining, second leg, which, in turn, determines the bias level of the power output stage. Control circuitry senses a parameter of the amplifier, such as DC bias or input signal level to generate a control signal which is applied to the first leg of the current mirror to thereby control bias level of the power output stage.
Claims3
An amplifier including:
- a differential amplifier stage,
- a voltage amplification stage, and
- a power output stage,
- wherein:
- a) the bias level of the output stage is proportional to current through the voltage amplification stage, and
- b) the voltage amplification stage includes a current mirror whereby controlled current through a first leg of the current mirror controls current through the remaining, second leg, which, in turn, determines the bias level of the power output stage,
- the amplifier further including control circuitry for sensing a parameter of the amplifier to generate a control signal which is applied to the first leg of the current mirror to thereby control bias level of the power output stage.
Dependencies are inferred from the claim text.