Patent ID: 7688144

Claim:
A variable-gain wide-dynamic-range amplifier, comprising: an amplifier module for amplifying an input signal, the amplifier module comprising a plurality of amplifier units coupled to each other in parallel, the gains of the amplifier units being different; a control unit for enabling at least one of the amplifier units according to a gain control signal, the at least one of the amplifier units which is enabled being for outputting a current signal in response to the input signal; and an output current regulating circuit for receiving the current signal which is outputted from the at least one of the amplifier units which is enabled, and regulating the magnitude of the current signal to output an output signal accordingly under the control of the control unit, each of the amplifier units being coupled to the output current regulating circuit in series; wherein the control unit is for controlling the output current regulating circuit according to the gain control signal; wherein the gain control signal corresponds to the magnitude of the input signal, and the control unit comprises: a pre-segmenting unit for receiving the gain control signal, and outputting a plurality of enabling signal accordingly to respectively enable the amplifier units according to the magnitude of the gain control signal, and further for generating a segment control signal according to the gain control signal, the output current regulating circuit regulating the magnitude of the current signal according to the segment control signal, wherein the segment control signal is substantially of a sawtooth-like waveform relating to an axis of the input signal strength when the gain control signal increases or decreases with respect to the linear change in the strength of the input signal.