A Low-Power Ring Oscillator Using Pull-Up Control Scheme Integrated by Metal–Oxide TFTs

This paper proposes a pull-up control scheme in the pseudo-CMOS inverter to design a low-power ring oscillator (RO) realized by only n-type transistors. For comparing 11-stages, the proposed RO and the conventional RO are both fabricated by metal-oxide thin-film transistors with the etch stop layer structure. It is measured that the power-delay product of the proposed RO is reduced by more than 50% under the same value of supply voltage. At the same oscillation frequency, the power consumption tends to be reduced by 18% as oscillation frequency increases. Furthermore, the peak-to-peak voltage of the proposed RO can almost receive a full swing at any supply voltage.