Monolithic active pixel sensors with on-pixel amplification and double sampling operation

Monolithic Active Pixel Sensors (MAPS) constitute a novel technique for silicon position-sensitive detectors. Their development is driven by highly demanding performances of the vertex detector foreseen at the future linear collider. This paper presents a new approach for a detector based on the MAPS principle. The pixel concept proposed is foreseen to match with signal discrimination implemented on the chip. It combines on-pixel signal amplification with double sampling operation, and provides a signal resulting from the difference between the charges collected in two consecutive time slots. The device can be fabricated in a cheap standard CMOS process, using a wafer made of a moderately doped medium. The new pixel design uses only NMOS transistors, nwell/psub and pdiff/nwell diodes and poly1-to-poly2 capacitors. It is based on a principle of switched operation circuits with 15 transistor switches close to the minimum size and 14 transistors used for the signal amplification.