Ring oscillator based injection locked clock multiplier

Phase-locked loop;Injection locking;Ring oscillator;High-performance clocking

Coombs, Daniel R ; Hanumolu ; Pavan K.

关键词: Phase-locked loop;    Injection locking;    Ring oscillator;    High-performance clocking;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/97744/COOMBS-THESIS-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This thesis describes a ring-based injection locked clock multiplier (ILCM) designed with the goal of generating a high-frequency and low-jitter clock. Building on prior research done on injection locking, this design uses a reference frequency doubling technique to push the noise bandwidth of the circuit to Fref/3 to suppress DCO noise to a large extent. A background duty cycle error correction technique is employed to correct errors on the doubled clock that could be detrimental to performance. The design also modifies an existing architecture to achieve type-II suppression of DCO noise in order to fully suppress the flicker noise which becomes prevalent in low process nodes. The prototype ILCM was fabricated in TSMC 65 nm CMOS technology. Thorough testing was performed to characterize the effectiveness of the aforementioned techniques. The circuit achieves 340 fsrms integrated jitter when operating at 5 GHz while only consuming 5.3 mW of power. The ILCM's figure of merit, -242.4 dB, is on par with state-of-the-art ring-based clock multipliers while operating at a much higher output frequency and multiplication factor than previously published work. These results indicate the effectiveness of reference frequency doubling in a ring-based, high-performance clock multiplier design.