Device for canceling input-stage thermal noise of resistive feedback power current amplifier

The invention discloses a device for canceling input-stage thermal noise of a resistive feedback power current amplifier. The device consists of a power current amplifier and a noise canceling circuit, wherein the power current amplifier consists of a transconductance input stage, an output current signal copy stage, a resistive current parallel negative feedback network and a resistive current series negative feedback network; the noise canceling circuit consists of a noise current signal detection stage and a mixed current signal synthesis stage and is cascaded in sequence; an output end of the transconductance input stage, an input end of the noise current signal detection stage and an input end of the resistive current parallel negative feedback network are connected in series in sequence; one input end of the mixed current synthesis stage is connected with one output end of the current signal copy stage. Since the noise of the noise canceling circuit can be inhibited by the transconductance input stage, the noise canceling effect of the device is better than that of the conventional noise canceling circuit.