Temperature compensation method for logarithmic CMOS vision sensor using CMOS voltage reference Bandgap technique

A temperature compensation method for logarithmic CMOS vision sensor is presented in this paper. This method is inspired from CMOS Bandgap Voltage Reference technique. The proposed method uses simple circuits located in the column amplifier. As systems using Bandgap technique, our circuits generate V_PTAT1 and V_PTAT2 voltages to compensate temperature variation of the sensor output signal voltage (Out-AC-Signal voltage) which we call V_CTAT1 and output reference voltage (V_Ref-ph voltage) which we call V_CTAT2. With this method, a good temperature stability of the sensor response in the temperature range from -30°C to 125°C is obtained. The great advantage of this method that we obtain a good temperature compensation for the output voltages and it conserves all pixel characteristics like fill factor and the photositive pixel array area. This method has been verified via Cadence simulation in a 0.35 μm CMOS technology. This method and the complete circuit have also been presented with the associated results.