DESIGN OF VCO USING CURRENT MODE LOGIC WITH LOW SUPPLY SENSITIVITY

Abstract

The function of an oscillator is to convert dc ener gy into RF. Voltage Controlled Oscillator (VCO) is a type of oscillator whose output frequency can be varied by a control voltage. Here the VCO is designed using 0.18µm CMOS-RF technology using current mode logic. The Current mode logic is the fastest logic and is mainly used in Clock and Data Recovery appli cations. Current mode logic (CML) is a differential logic and provides noise im munity. Using the proposed design the current mode logic VCO operates with a supply voltage of 1.8 V and frequency varies from 2 MHz to 2.5 MHz. Its normalized supply sensitivity is 0.976 and optimum sensitivity is 0.966.