Patent ID: 8289077
Filing Date: 2012-10-16
Classification: H03F

Abstract:
1. A signal processor comprising an amplifier comprising: a pair of complementary differential pairs such that one differential pair comprises transistors having a polarity opposite to that of transistors in the other differential pair, the one and the other differential pair being coupled to commonly receive a differential input signal, which has a common mode component; and a current combining circuit arranged to combine output currents of the one and the other differential pair so as to obtain an output current that varies as a function of the differential input signal, the one and the other differential pair being each provided with a biasing circuit for providing a tail current that varies with the common mode component in a substantially linear fashion, the current combining circuit comprising: the amplifier being provided with a feedback circuit so that the differential input signal represents a difference between an input signal and an output signal of the amplifier.