PHASE MIXING CIRCUIT OF PHASE SELECTOR

摘要

PURPOSE: A phase mixing circuit of a phase selector is provided, which controls a current source bias voltage of a phase mixer directly without using a digital/analog converter. CONSTITUTION: A phase mixing part(21) comprises differentially-coupled NMOS transistors(M3,M4) receiving an input signal(InE) and its differential signal(InEb) and differentially-coupled NMOS transistors(M1,M2) receiving an input signal(In0) and its differential signal(In0b), and controls phases of output signals(out,outb). Current control parts(22A-22K)(23A-23K) control a current value of a current source supplied to the NMOS transistors by controlling a bias voltage(Vbias) directly according to an input digital value. The current control part comprises NMOS transistors(M00-Mk0)(M03-Mk3) connected to sources of the NMOS transistors(M1-M4), and NMOS transistors(M01-Mk1,M02-Mk2)(M04-Mk4,M05-Mk5) controlling biases of the above NMOS transistors(M00-Mk0)(M03-Mk3) according to the input digital value.