Triple Well CMOS Active Pixel Sensor with In-Pixel Full Signal Analog Processing

We report on a new approach in the design of CMOS monolithic active pixel sensor (MAPS). We realized a first MAPS prototype chip implementing at the pixel level the standard processing chain commonly used for capacitive detectors. The in-pixel signal processing channel includes a low noise charge preamplifier, a shaper, a discriminator and a latch. This readout approach, realized exploiting the triple well option available in the 0.13 μm process by STMicrolectronics, is compatible with already available architectures performing data sparsification at the pixel level. This feature will be implemented in future development of our device to improve the readout speed potential of these sensors with respect to existing MAPS. Using a charge preamplifier to perform charge to voltage conversion, we also extended the area of the sensing electrode to increase the signal collected by a single pixel. The first prototype chips have been successfully tested with very encouraging results. In this paper we summarize the performance of the front-end electronics and present the response of the sensor to ionizing radiation.