Cleopatra: a 12-channel recycling integrator ASIC for the readout of hydrogenated amorphous silicon detectors in radiotherapy dosimetry

The Cleopatra ASIC is a 12-channel prototype ASIC for the readout of hydrogenated amorphous silicon sensors used for real-time dosimetry in radiation diagnostic and radiation therapy. The architecture is based on a current to frequency conversion based on the recycling integrator principle in order to cover a dynamic range of four orders of magnitude with high linearity. Three different input amplifier configurations have been implemented in order to check the trade-off between detector capacitance and maximum output frequency. Cleopatra has been designed in CMOS 28 nm technology and succesfully tested in laboratory.