Current-controlled oscillator with practical implementation in phase-locked loop

A current-controlled oscillator implemented in CMOS technology is presented. The oscillator utilizes a Schmitt-trigger, pass transistors, current mirrors and grounded capacitor with /spl plusmn/3 V power supplies. Simulation was carried out using Pspice 7.1, with SCNA parameters obtained through MOSIS. Simulation results show that, the frequency range of the oscillator is controlled by a DC current over a broad range of values. This ICO is suitable in the design of current-mode phase locked loop. Practical implementation of current-mode PLL based on the AD844 (current feedback operational amplifier from Analog Devices) is also given.