 Image Number 4 for United States Patent #6011440.
Amplifier circuitry is provided having an output voltage range that exceeds its supply rail voltage. Such an amplifier may be useful in battery powered applications calling for driving a high impedance load with a low current, moderate bandwidth signal The amplifier circuitry includes a transconductance amplifier, for providing a high output impedance, and a charge pump DC/DC converter, for providing a high supply voltage to the transconductance amplifier. In one embodiment of the invention, the gain of the amplifier is a function of the input voltage so as to linearize a transfer function between the amplifier input and a response of a load at the amplifier's output.
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