This paper presents a proof of concept performed on a new and very simple CMOS circuit configuration that implements a radiation dosimeter based on the threshold voltage difference (VTH) principle. The circuit used does not use resistors and all the transistors work in strong inversion, their mobility factor being completely canceled by the proposed architecture. Its operation exploits the relationship between radiation and VTH shifting, which allows, through a circuit configuration, to compensate for temperature variation and amplify the reaction to radiation, making it ideal for integrated industrial applications due to its simplicity and good operation. The circuit was designed for operation in areas naturally at risk of radiation, for example nuclear power plants or radiological clinics. Its advantage over other circuits that perform similar functions is mainly its low cost and simplicity of design.

This work presents a new design methodology for radio frequency (RF) integrated circuits based on a unified analysis of the scattering parameters of the circuit and the gm/ID ratio of the involved transistors. Since the scattering parameters of the circuits are parameterized by means of the physical characteristics of transistors, designers can optimize transistor size and biasing to comply with the circuit specifications given in terms of S-parameters. A complete design of a cascode low noise amplifier (LNA) in MOS 65 nm technology is taken as a case study in order to validate the approach. In addition, this methodology permits the identification of the best trade-off between the minimum noise figure and the maximum gain for the LNA in a very simple way.

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Oscillation based testing (OBT) has proven to be a simple and effective test strategy for numerous kind of circuits. In this work, OBT is applied to a radiation sensor to be used as a VLSI cell in embedded applications, implementing an oscillation built-in self-test (OBIST) structure. The oscillation condition is achieved by means of a minimally intrusive switched feedback loop and the response evaluation circuit can be included in a very simple way, minimizing the hardware overhead. The fault simulation indicates a fault coverage of 100% for the circuit under test.Keywords: fault simulation, mixed signal testing, OBIST, oscillation-based test, VLSI testing.

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