In this work, a novel approach for measuring relative temperature variations across the active area of a CMOS image sensor itself is presented. 555 Image pixels have been replaced by temperature sensors pixels (Tixels) in the same pixel array layer. Both sensors, pixels and Tixels, utilize the same readout structure to obtain the data. This approach of measuring temperature variations in the pixel array can be used to compensate for dark signal non-uniformity. Measurements of dark current and temperature have been performed in a temperature range of −40 and 90 °C. Results show that pixels and Tixels are working by using the same readout system based on source followers and column amplifiers. The average dark current of the image sensor increases with temperature in the temperature range of −40 and 60 °C, and at the same time, Tixels show high linear response, having a temperature error less than 0.6 °C after a 1st order best curve fitting.@en

This paper presents an analysis and calibration of process variations for an array of temperature sensors, which are incorporated into a CMOS image sensor chip. Making use of the experimental results of more than 500 temperature sensors implemented on the same chip, the proposed calibration method has removed their process variations from 14.3 % to 2.5 % (3 sigma).@en

In this work, a novel approach is presented for measuring relative temperature variations inside the pixel array of a CMOS image sensor itself. This approach can give important information when compensation for dark (current) fixed pattern noise (FPN) is needed. The test image sensor consists of pixels and temperature sensors pixels (=Tixels). The size of the Tixels is 11 μm × 11 μm. Pixels and Tixels are placed next to each other in the active imaging array and use the same readout circuits. The design and the first measurements of the combined image-temperature sensor are presented. @en