Radiation hardened bootstrapped switch in 0.18μm CMOS process

This paper presents a low-voltage bootstrapped switch that adopts a new technique to achieve its radiation hardening by design (RHBD). In order to improve the performances of CMOS switches used for switched-capacitor (SC) circuits, such as in sample-and-hold circuits or in pipeline analog-to-digital SC amplification stage, bootstrapped techniques are necessary but should not be directly applied for circuits operating in a radiative environment. The critical nodes of the conventional bootstrapped switch will be highlighted and the devised method to size correctly certain MOS transistors within the bootstrapped circuit will be shown. To verify the proposed methodology, a bootstrapped switch is designed in a HV 0.18μm CMOS technology and its performances are compared to a conventional bootstrapped architecture.