A high dynamic range, high linearity CMOS current-mode image sensor for computed tomography

In this work we show a high dynamic range current-mode detector for computer tomography applications. A regulated current mirror structure has been implemented at pixel level that provides with 17 bits dynamic range and a noise floor below 3 pA[RMS]. Non-linearity is kept below 2% and signal bandwidth is higher than 10 kHz. A test structure with 4x4 pixel array is presented in this paper. Both photodiode and current mode amplifier have been integrated into the same CMOS standard process.