An Asymmetric Static Comparator for RC Oscillator Achieving $21.6 \text{ppm} /{}^{\circ} \mathrm{C}$ Temperature-Stability

This work proposes an asymmetric static comparator for the RC oscillator to achieve a low temperature coefficient. The design uses parallel diode connected transistors in the pull down circuit to introduce asymmetricity. The operation of pull down network is guided by the control circuit to achieve frequency stability for the temperature range of $\mathbf{- 3 0}{}^{\circ} C$ to $\mathbf{+ 7 5}{}^{\circ} C$. The RC oscillator is designed in UMC 65 nm technology with a supply voltage of 1 V. The obtained frequency of oscillation is 3.42 MHz while consuming $7.01 \mu \mathrm{W}$ of power. This work reports the lowest temperature coefficient of RC oscillator which is $21.6 \text{ppm} /{}^{\circ} \mathrm{C}$, resulting in figure of merit of 163.5.