A four channel, input-level-tunable data acquisition chip, realized with an analog/digital array for research and education

Presents a student design of a data acquisition chip. The basic array was designed in a 4 μm, single-poly, single-metal CMOS technology. The goal is to provide short fabrication terms to reduce project durations in research and education. In contrast to other approaches the authors use transistor array cells in the digital and analog part. For the analog part this was achieved through a basic transistor layout where different W/L sizes can be chosen by different metalization of the same transistor. The complete array is preprocessed without the metalization layer. To show the capabilities of such an array, a data acquisition chip was developed during a one-man student project. This circuit contains four analog input channels, one analog MPX, and an 8-bit A/D converter in successive approximation technique with on-chip channel control