Adaptable interface circuits for flexible monitoring of temperature and movement

This paper describes the development of two small data acquisition chips with on board interface circuits for a miniaturised capacitive accelerometer, as well as for a set of thermistors. They are intended for use in biomedical, implantable telemetry application, requiring low power and small size for the entire system. Beside the typical aspects of circuit design, emphasis is also put on the overall system design, to pinpoint to the typical constraints of the application. This leads to one of its most important features: the flexible specifications, allowing a user-defined setting of the monitoring windows, after the device is manufactured. In the paper this concept is explained, and an example of a hard-wired system and a software controlled system are given.