A study of the effect of temperature changes on the interpolating time counter

This paper presents an analysis of the impact of ambient temperature changes on main parameters of the interpolating time counter. The performed tests reveal that a relatively small change in the ambient temperature of 1°C causes a measurement error of the counter as large as 3.5 ps. The thorough research of two stages of interpolation of the counter allowed determining the main sources of the error. One of them is the temperature drift of widths of four-phase clock (FPC) segments in the first interpolation stage (FIS). It equals 2.5 ps/°C. The widths of FPC phases directly influence the active range of the second interpolation stage (SIS) and its offset. The test results also show that the temperature drift of the offset has a greater impact on the measurement accuracy than the temperature-driven changes of quantization steps in SIS. The presented conclusions are the first step to develop a new method for reducing the impact of changes in the ambient temperature on the measurement accuracy of the interpolating time counter.