CMOS X-ray Image Sensor Array

This paper describes a pixel array for x-rays imaging consisting in an 8×8 photodiode array fabricated in CMOS technology, with the respective readout circuit. Above the photodiodes, an array of scintillating CsI:Tl crystals are placed. So, the x-ray energy is first converted to visible light by the scintillating crystals, which is then detected by the photodiodes. The photocurrent produced by each photodiode is amplified, converted to a voltage and stored in a capacitor. Finally, the voltage of each capacitor is read by the readout circuit.