Tarbiat Modares University The Modares Journal of Electrical Engineering 2228-527X 12 2 2012 07 01 A High Dynamic Range Digitally-Controlled Oscillator (DCO) for All-Digital PLL Systems • اسیلاتور کنترل شونده‌ی دیجیتالی با محدوده‌ی فرکانسی گسترده برای حلقه های قفل فاز تمام دیجیتال 16 21 12889 EN Samira Jafarzade Tarbiat Modares University, samira. Abumoslem Jannesari Tarbiat Modares University, Journal Article <span>In this paper, a new high dynamic range Digitally-Controlled Oscillator (DCO) for All-DPLL systems is proposed. The proposed DCO is based on using a ΔΣ modulator as a Digital-to-Analog converter. Using ΔΣ DAC can provide a very high resolution (18-bit) control on the DCO. The ΔΣ DAC output is a 2-level pulse signal that needs to be filtered for cancelling the out of band shaped noise. The used ΔΣ modulator is a 4^th order MASH ΔΣ modulator working with the OSR of 128 and the sampling frequency of 450MHz. the proposed DCO is used in a PLL to synthesize the frequency in the range of 1700</span><span>MHz</span><span> to 1800MHz for GSM-1800 application. The achieved phase noise for this PLL based synthesizer in whole the range is -115 dBc/Hz at the offset frequency of 500 kHz. The designed ADPLL including the DCO is simulated in ADS with 0.18µm CMOS technology.</span> https://mjee.modares.ac.ir/article_12889_b458201027eb55a7a6dcb41b0af61993.pdf