Low-power, Low-noise Sensor Interface Circuits for Biomedical Applications

Biomedical and healthcare applications provide attractive opportunities for the semiconductor sector. In both fields, the target is to gather data from multiple sensor nodes with minimal power consumption while maintaining low noise operation. However, designing a sensor interface circuit for such applications is challenging due to its harsh environment. Also, in such cases, the trade-off between available resources and performance among the components both in the analog front-end and in the digital back-end is crucial.

This talk will cover the design strategies of sensor interface circuits. Starting from a basic op-amp, we will first explore the difficulties, limitations, and potential pitfalls in the sensor interface, as well as the strategies to overcome such issues. Low noise operation leads to two dynamic offset compensation techniques, auto-zeroing, and chopper stabilization. After that, system-level considerations for better key metrics, such as energy efficiency, will be introduced. Several state-of-the-art instrumentation amplifiers that emphasize different parameters will also be discussed. We will then see how the signal analysis part impacts the analog sensor interface circuit design. The lecture will conclude with interesting aspects and opportunities that lie ahead.