A highly linear CMOS current-controlled oscillator using a novel frequency detector

A CMOS current-controlled oscillator capable of operating over a range of frequencies (100 MHz to 1.0 GHz) is presented. It achieves a highly linear frequency-variation with control current by using a novel switched-capacitor frequency- detector and a simple single-ended ring oscillator in a feedback loop. The simple low-power circuit does not use operational amplifiers or resistors. This circuit, realized in TSMC 0.18-mum CMOS process shows 0.1% linearity over a tuning range of 100 MHz to 1.0 GHz. The simulated results show power dissipation of 1.7 mW at 1.0 GHz and 326 muW at 100 MHz from a 1.8 V supply.