A mixed-signal sensor interface microinstrument

A single-chip implementation of a microinstrumentation system is presented. The chip incorporates voltage, current, and capacitive sensor interfaces; a temperature sensor; a 20-channel, 12-bit analog-to-digital converter; and an 8-bit microcontroller with a 16-bit hardware multiplier and a 40-bit ac cumulator. Serial and parallel interfaces allow digital communication with a host system. Fabricated in a standard 0.35 mum digital CMOS process, the die occupies 3.8 mm x 4.1 mm, operates from a nominal supply voltage of 3 V , and draws 16 mA when fully powered (850 muA standby current). To facilita te: testing of the prototype, extra pads are bonded out to package pins. Th e chips are packaged in 132-pin ceramic pin-grid-array packages. (C) 2001 E lsevier Science B.V. All rights reserved.