Low-Voltage High-Speed Ring Oscillator With a-InGaZnO TFTs

• Published in: IEEE journal of the Electron Devices Society 2020, Vol.8, p.584-588
• Main Authors: Tiwari, Bhawna, Bahubalindruni, Pydi Ganga, Santos, Angelo, Santa, Ana, Figueiredo, Catia, Pereira, Maria, Martins, Rodrigo, Fortunato, Elvira, Barquinha, Pedro
• Format: Article
• Language: English
• Subjects: CMOS; Electric potential; Fabrication; Gallium; High speed; High speed ring oscillators; Indium gallium zinc oxide; Inverters; Logic gates; low-voltage designs; oxide TFTs; Ring oscillators; Semiconductor devices; Signal generation; Thin film transistors; Voltage; Voltage measurement
• ISSN: 2168-6734; 2168-6734
• DOI: 10.1109/JEDS.2020.2997101

This paper presents a high-speed ring oscillator (RO) with amorphous Indium-Gallium-Zinc-Oxide Thin-film transistors (a-IGZO TFTs). The proposed RO reduces the delay of a single stage inverter using intermediate signals generated within the RO, hence, improving the speed. To validate the proposed idea, two conventional ROs (with diode-load load inverter and bootstrapped pseudo-CMOS inverter) and the proposed RO were fabricated at a temperature ≤ 180°C. Measured results of the proposed RO have shown a frequency and power-delay-product (PDP) of 173.2 kHz and 0.7 nJ at a supply voltage of 6V. Further, it shows approximately 155% (44%) increase in frequency and 14% (24.5%) decrease in PDP compared to diode-load inverter (bootstrapped pseudo-CMOS inverter) based ROs. Therefore, the proposed RO finds applications in low-voltage and high speed designs for timing signal generation.