Evaluating Adaptive Clocking for Supply-Noise Resilience in Battery-Powered Aerial Microrobotic System-on-Chip

A battery-powered aerial microrobotic System-on-Chip (SoC) has stringent weight and power budgets, which requires fully integrated solutions for both clock generation and voltage regulation. Supply-noise resilience is important yet challenging for such SoC systems due to a non-constant battery discharge profile and load current variability. This paper proposes an adaptive-frequency clocking scheme that can tolerate supply noise and improve performance when implemented with an integrated voltage regulator (IVR). Measurements from a ‘brain’ SoC, implemented in 40 nm CMOS, demonstrate 2$\times$ performance improvement with adaptive-frequency clocking over conventional fixed-frequency clocking. Combining adaptive-frequency clocking with open-loop IVR extends error-free operation to a wider battery voltage range (2.8 to 3.8 V) with higher average performance.

I. Introduction

Robotics have grabbed much public imagination these days with their promises for a range of versatile applications. A special branch of robotics is the recent development of microrobot which builds miniature robotics with characteristic dimensions less than 1 mm. Despite its small size, the microrobot embodies many of the essential components that can be found in regular-sized robots, such as power source and conversion, actuation, sensing, and autonomous control. Accommodating all these functionalities within the size limit of the microrobot provides fertile ground for the design of a highly integrated system-on-chip (SoC) targeted for robotic applications.