Low-Power and High-Sensitivity Interfaces for Integrated Sensors
Signals outputted from microelectromechanical systems (MEMS) transducers are often very weak, and the sensing interface circuits must exhibit very low noise levels to enable a large dynamic range of detection. Capacitive sensing interfaces exhibit high temperature stability, low power consumption, low noise, and are appropriate to implementations in CMOS. Different methods, such as switched capacitor charge integration and continuous-time current or voltage sensing circuits are potential implementation candidates. In addition, frequency sensing can be used with resonant transducers, such as MEMS resonators. Such a sensing interface involves circuitry such as phase-locked loops or counters. The purpose of this project is to design a multi-sensor interface that supports different sensing schemes in order to accommodate a wide range of micro-transducer types.
The market for low-power sensing interfaces is growing since smart phones and other portable electronics embed more sensing function (e.g., motion, environmental etc.). As such, novel low-power and/or high-sensitivity interfaces tailored to mobile applications with support for multiple sensor and transducer types are expected to have a significant impact in the sensing business.
This project involves creating a CMOS integrated circuit which can be used to convert different (e.g., capacitive, frequency, resistive) transducer signals (either in parallel or sequentially) to the digital domain with very low power specifications. Another aspect of this project pertains to the testing of the interface with available commercial transducers requiring some more elaborate test benches. The circuitry will be simulated and will be fabricated through our partner foundry. The fabricated circuit will then be tested with state-of-the-art equipment available in our laboratories. Different MEMS transducer models will also be implemented in order to allow for their simulation with the designed interface circuit.
