CMOS sensor interface for a robotics LAN

The authors describe a CMOS design for interfacing low-level analog levels from sensors to a robotics network. This interface IC contains analog signal conditioning, an 8-bit ADC (analog-to-digital converter), and protocol control for the interface between simple analog sensors and the local-area network. The ADC uses a combination linear switched capacitor array and a resistor-string successive approximation register technique for conversion. A bandgap reference utilizes the vertical n-p-n device obtained using the substrate as a collector. Calculated analog and digital power dissipation are 4.1 mW and 8.1 μW/Hz, respectively. Technology is 3-μm double-polysilicon, single-metal for the 3.5×4.0-mm² chip