Programmable Low-Power Low-Noise Capacitance to Voltage Converter for MEMS Accelerometers

Guillermo Royo; Carlos Sánchez-Azqueta; Cecilia Gimeno; Concepción Aldea; Santiago Celma

doi:10.3390/s17010067

Programmable Low-Power Low-Noise Capacitance to Voltage Converter for MEMS Accelerometers

Sensors (Basel). 2016 Dec 30;17(1):67. doi: 10.3390/s17010067.

Authors

Guillermo Royo¹, Carlos Sánchez-Azqueta², Cecilia Gimeno³, Concepción Aldea⁴, Santiago Celma⁵

Affiliations

¹ Group of Electronic Design-Aragón Institute of Engineering Research, Universidad de Zaragoza, 50009 Zaragoza, Spain. royo@unizar.es.
² Group of Electronic Design-Aragón Institute of Engineering Research, Universidad de Zaragoza, 50009 Zaragoza, Spain. csanaz@unizar.es.
³ Institute of Information and Communication Technologies, Electronics and Applied Mathemathics, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium. cecilia.gimenogasca@uclouvain.be.
⁴ Group of Electronic Design-Aragón Institute of Engineering Research, Universidad de Zaragoza, 50009 Zaragoza, Spain. caldea@unizar.es.
⁵ Group of Electronic Design-Aragón Institute of Engineering Research, Universidad de Zaragoza, 50009 Zaragoza, Spain. scelma@unizar.es.

Abstract

In this work, we present a capacitance-to-voltage converter (CVC) for capacitive accelerometers based on microelectromechanical systems (MEMS). Based on a fully-differential transimpedance amplifier (TIA), it features a 34-dB transimpedance gain control and over one decade programmable bandwidth, from 75 kHz to 1.2 MHz. The TIA is aimed for low-cost low-power capacitive sensor applications. It has been designed in a standard 0.18-μm CMOS technology and its power consumption is only 54 μW. At the maximum transimpedance configuration, the TIA shows an equivalent input noise of 42 fA/ Hz at 50 kHz, which corresponds to 100 μg/ Hz .

Keywords: accelerometer; capacitive sensing; microelectromechanical systems (MEMS); synchronous demodulation; transimpedance amplifier.