Gate-all-around OTA´s for rad-hard and high-temperature analog applications

Performance of operational transconductance amplifiers (OTA´s) fabricated in the gate-all-around SOI technology is described at elevated temperature and after total dose irradiation. Design guidelines using two analog parameters (early voltage and transconductance to drain current ratio) are proposed for correct operation in these two different harsh environments. The design methodology using the two analog parameters of interest is proposed and applied to the specific case of the GAA technology. The temperature and dose dependence of the two above design parameters are then presented. Two different OTA architectures are considered: a single-stage amplifier and a folded cascode amplifier. Experimental results obtained separately for each environment are discussed. High-temperature measurements were performed up to 300°C, while total dose measurements were obtained for doses up to 15 Mrad(Si) total dose of gamma rays from a ⁶⁰Co source