Low-jitter, high-linearity current-controlled complementary metal oxide semiconductor relaxation oscillator with optimised floating capacitors

摘要

A new complementary metal oxide semiconductor (CMOS) relaxation oscillator featuring with high linearity and low-jitter is presented in this study. The high linearity between the frequency and control current is achieved by adopting the floating capacitor and the independent charged and discharged loops. The low-jitter performance is gained because of that the voltage across the floating capacitor is larger than the conventional oscillator. The proposed circuit is compatible with standard CMOS process and one test-chip with typical frequency of 6.66 MHz was implemented in the 0.5 μm (bipolar-CMOS-double-diffused metaloxide semiconductor (DMOS)) (BCD) process. The measured results show that <;0.86% non-linearity in the current-frequency transfer function from 1 to 6.66 MHz without trimming. The cycle-to-cycle jitter was <;112 ppm.