A 6nW 30.8kHz Relaxation Oscillator with Sampling Bias-Free RC Circuit and Dynamic Power Scaling in a 12nm FinFET

An ultra-low power 30.8kHz relaxation oscillator (RxO) is presented. To achieve low power consumption, a sampling bias-free RC circuit is proposed and leveraged in a frequencylock-loop. Moreover, dynamic power scaling is implemented by adopting local phase allocation and global duty control. In this work, the RxO consumes only 6.05nW under a 0.7V supply. The FoM achieves 0.196nW/kHz, and the active area of RxO occupies 0.063mm 2 in a 12nm FinFET process.