[paper] Open-source design of integrated circuits

Patrick Fath, Manuel Moser, Georg Zachl. Harald Pret

Open-source design of integrated circuits

Elektrotech. Inftech. (2024)

DOI: 10.1007/s00502-023-01195-5

* Institute for Integrated Circuits, Johannes Kepler University Linz, Austria

Abstract: This paper presents the design of a self-clocked 12-bit non-binary fully differential SAR-ADC using the SKY130 open-source PDK. The entire mixed-signal circuit design and layout were created with free and open-source software. The ADC reaches a sample rate of up to 1.44MS/s at 1.8V supply while consuming 703μW of power on a small 0.175mm area. A configurable decimation filter can increase the ADC resolution up to 16 bits while using an oversampling factor of 256. A 9‑bit thermometer-coded and 3‑bit binary-coded DAC matrix using a 448 aF waffle-capacitor results in a total capacitance of 1.83pF per input. Realizations of configurable analog functions using the form factor of SKY130 high-density standard cells allow the parametrization of an analog circuit in a hardware description language and hardening of the macro in an intentionally digital workflow.

FIG: Block diagram of the proposed open-source design flow,

including the essential tools and used/generated files

Acknowledgements: The authors thank Johannes Kepler University for funding the open-access publication, Google and SkyWater Technologies for igniting this recent wave of open-source IC design, and the large crowd of enthusiasts spending their time on developing and maintaining an extensive array of exciting open-source EDA projects. Open access funding provided by Johannes Kepler University, Linz.