Integrated test support for intelligent sensors

The importance of integrating test support into the next generation of intelligent sensors has evolved to a point where DfT is becoming mandatory and BIST features key specifications to ensure system test does not dominate manufacturing costs and performance can be guaranteed in the field to satisfy safety critical specifications. This paper summarises the issues and describes an example of how an efficient on-line test mode can be implemented at minimal additional cost. Other work that may provide designers with efficient test options includes on-line test functions for fully differential interface circuits and BIST structures for interface functions such as amplifiers, filters and converters implemented in switched current technology. In addition, the extension of a reliability indicator technique referred to as IDDQ for digital ASICS may be practical to allow use with mixed signal integrated systems