Digitally controlled oscillator with storage based randomization for spurs reduction

This paper presents a storage based randomization method for spurs reduction in digitally controlled oscillator (DCO). The storage size is very compact as compared with conventional large size. A modified linear feedback shift register is applied for random address generator. The proposed method has been demonstrated in field programmable gate array (FPGA) with a digitally controlled oscillator. The spurious-free dynamic range (SFDR) of proposed method is 32.3 dB as compared with conventional method´s 28.9 dB. The proposed method has successfully reduced the spurs with very small storage for randomization.