A 32-ppm/°C 0.9-nW/kHz Relaxation Oscillator with Event-Driven Architecture and Charge Reuse Technique - Xinhang Xu; Ye, Siyuan; Gao, Jihang; Zhang, Yihan; Shen, Linxiao; Ye, Le (2022 IEEE International Symposium on Circuits and Systems (ISCAS), 2022)