A Programmable On-Chip Reference Oscillator With Slow-Wave Coplanar Waveguide in 14-nm FinFET CMOS

Jeongho Hwang, Sang-Hyeok Chu, Gyu-Seob Jeong, Yeojoon Youn, Wooseok Kim, Taeik Kim, Deog-Kyoon Jeong

Abstract: This brief presents a programmable on-chip reference oscillator based on a slow-wave coplanar waveguide (S-CPW). The frequency is determined mainly by its geometric structure with floating stripes, thereby enjoying an advantage of being less sensitive to PVT variations, especially due to self-heating of FinFET devices. The S-CPW is carefully designed with 3-D EM simulations. In addition, the proposed reference oscillator is widely programmable for multi-standard System on-a-Chip (SoC) applications utilizing a programmable divider using 7-bit multi-modulus divider. The oscillator fabricated in 14-nm FinFET CMOS technology consumes 2.8 mW at the frequency of 200 MHz and occupies an active area of 0.53 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Phase noise is -147.5 dBc/Hz at 1-MHz offset at the frequency of 25 MHz. The proposed oscillator exhibits frequency variation of only 37 ppm/°C and 0.52 %/V with 25-MHz clock generation.