LC RESONANCE TYPE VOLTAGE CONTROL OSCILLATOR

摘要

PURPOSE: An LC resonant voltage-controlled oscillator is provided which is able to be integrated into a chip to reduce the area of the chip and the number of external components to decrease costs, and has a wide controllable frequency domain when applied to a PLL. CONSTITUTION: An LD resonant voltage-controlled oscillator includes the first inductor(L31) one end of which is connected to a power supply and the second inductor(L32) one end of which is connected to the power supply, and the first active element(M1) whose drain is connected to the other end of the first inductor. The oscillator further has the second active element(M2) whose drain is connected to the other end of the second inductor and the gate of the first active element and whose gate is connected to the drain of the first active element, and a current supply(I) one end of which is connected to the sources of the first and second active elements. The oscillator also has the third active element(M3) whose gate is connected to the other end of the first inductor and whose source and drain are connected to a control voltage, and the fourth active element(M4) whose gate is connected to the other end of the second inductor and whose source and drain are connected to the control voltage.