60Co gamma irradiation effects on Low-Voltage Differential Signaling (LVDS) receivers: Analysis with impedance spectroscopy

Impedance Spectroscopy (IS), a well-established technique in electrochemistry, is applied in this work to investigate Total Ionizing Dose (TID) effects on Low-Voltage Differential Signaling (LVDS) receivers widely used in high-speed serial links. These devices were irradiated with 60Co gamma rays at a dose of 15.4 kGy with a dose rate of 364 Gy/h. Measurements of the current drawn by the receivers, and key waveform parameters such as amplitude, rise time, fall time, and bit error rate, showed no differences before and after irradiation. However, IS analysis, complemented by I-V measurements, identified radiation-induced changes that are generally difficult, or even impossible, to detect with traditional methods. IS enabled the modeling of different device sections through equivalent circuits based on two time constant networks, revealing TID effects both in the power rail, in the Electrostatic Discharge (ESD) protection circuit, as well as in the differential input pair and output buffer. This work shows that IS is a promising technique to investigate radiation effects on solid-state devices.