Four quadrant multiplying circuit driveable at low power supply voltage

摘要

A four quadrant multiplying circuit includes a first compression circuit having a PMOS differential input structure for reducing and outputting a first input voltage and a reference voltage by a predetermined ratio; a second compression circuit having an NMOS differential input structure for reducing and outputting a second input voltage and a reference voltage by a predetermined ratio; a current converting circuit for converting a constant current input from a constant-current circuit to a first and a second constant current on the basis of the second input voltage and reference voltage reduced by a predetermined ratio and output by the second compression circuit; first and second voltage converting circuits. The first and second constant currents output by the current converting circuit are received by the device sources, and the outputs of the first and second voltage compression circuits are received by the device gates. A Gilbert cell for multiplying together the outputs from the first and second voltage converting circuits and outputting the multiplied voltage is also used.