From sensors to microsystems: a case study

The purpose of the paper is to describe the development of an optical interface used in the system REGISTRON of BOBST for the alignment of paper in a rotary printing press. This alignment is based on the detection of small repairs preprinted on the paper. This miniaturisation and the cost optimisation leads to a system based on two ASICs: one ASIC including 8 photodiodes integrated with their transimpedance amplifier in a CMOS standard process and one ASIC which performs the operations of multiplexing, amplifying the signals delivered by 32 photodiodes. While the first ASIC is designed in full-custom, the second ASIC is realised in a mixed-mode gate-array.