High Precision Analog Multiplexers Enable Multi-Channel Data Acquisition in High Temperature Environments

Abstract A growing number of industries are calling for low power electronics that operate reliably at temperatures of 175C and higher. Many of these applications require a precision data acquisition signal chain in order to digitize analog data so that it can be collected and processed. We previously presented a characterized signal chain for a single channel of analog to digital conversion designed around a 600ks ps SAR ADC. However, many systems have a multitude of sensor signals that must be acquired at varying sample rates. In this work we discuss two new analog multiplexers rated for 175°C/210°C that allow multiple analog signals to be connected to the ADC input, enabling the design of a precision multi-channel data acquisition system. One multiplexer is designed on a robust dielectrically isolated process for high performance and low leakage over temperature, and one multiplexer is optimized for low power, low voltage applications. We will examine the architecture of these two integrated circuits, review the characterization over temperature and discuss example application signal chains.