ANALOG MULTIPLYING CIRCUIT

摘要

PURPOSE:To enable an operation by means of a low constant voltage source and to secure linearity in a wide in/out level area and a wide dynamic range by providing a common-mode output generating part which imparts the common- mode component of an input signal to a multiplying output generating part so as to remove an opposite phase component. CONSTITUTION:The output of the left half circuit of the circuit incorporated simultaneously the component of the input voltage V1 of an opposite phase input terminal 20 and the multiplying output component of the opposite input voltage V1 and the input voltage V2 of a common-mode input terminal 21. The differential circuit in the right half of the circuit adjusts the value of the constant voltage source 24 and the resistance values of resistors 28 and 29 and adds the opposite phase component of the voltage V1 being the adequate value. Thus, the V1 component in the output voltage V0 component of the output terminal 31 is removed so that only the multiplying component of V1 and V2 is obtained. Then, an analog multiplying circuit used for the modulating/ demodulating circuit of the transmitting/receiving circuit for a radio is constituted of the two stages in the number of the longitudinal load stages of a transistor.