Investigation of readout electronic dedicated to electromechanical audio sensor is presented. The circuit is able of reading piezoresistive gauge implemented with silicon nanowire (NEMS) and bring electromechanical signal to high-resolution digital output. Low-noise low-power CMOS operational transconductance amplifier (OTA) is presented. The low-noise amplifier (LNA) has been designed in a 0.28 μm CMOS process with a 2.5 V supply voltage and occupies an area of 120 × 160 μm 2 . For the Post-layout Simulation, the OTA achieves a 65 dB DC gain. It achieves a noise floor of 6 nV/√Hz within the frequency range from 1 Hz to 10 kHz. The total power consumption including the common mode feedback circuit (CMFB) and the biasing circuit is 150 μW.
This paper presents and discusses recent achievements in the realization of a miniaturized optical sensor based on photoacoustic detection and it illustrates the potential of the co-integration of Si-based Photonic Integrated Circuits, IC/MEMS and QCL technologies.
This paper presents a smart sensor microphone based on silicon nanowire resistive gauge for hearing aid applications through cochlear implant. The system includes the sensor together with its bias circuit, the preconditioning stage and the digital interface that ease integration on heterogenic system. One important concern of audio field is the wide dynamic range addressed since human hear is able to sense sound pressure level ranging from μPa to a few Pa. The hundred dB dynamic range circuit was designed to achieve the maximum resolution with a deep submicron CMOS technology suitable for implementation of extensive digital signal processing required in most today's application. Power consumption issue involved by application requirement is addressed with usual trade off related to embedded device. This is done at system level with a topology optimization.
The design and implementation of a CMOS integrated analog to digital interface dedicated to hybrid integration of MEMS resistive microphone is presented. Audio sensing is achieved with an innovative low-cost technology that uses single crystal piezoresistive silicon nanowires as transducer in a MEMS. The circuit composed of a low-noise instrumentation preamplifier followed by a single bit fourth order continuous-time sigma-delta modulator (CT-ΣΔM) includes bias circuit for sensor. To join low power applications where extensive digital processing is employed, 0.28 μm CMOS process with a 2.5 V supply has been adopted. The test chip occupies an area of 1 mm2. Post-layout simulation exhibits promising performances where noise density is below 8 nV/VHz within the frequency range from 10 Hz to 10 kHz. Complete interface circuit features a current consumption of 2.4 mA.
The design of CMOS integrated circuits dedicated to hybrid integration of a MEMS resistive microphone with readout interface is presented. Audio sensing is achieved with an innovative low-cost technology that implements piezoresistive detection in MEMS devices with single crystal silicon nanowires. The complete circuit includes a custom designed analog front-end consisting of a sensor conditioning and a fourth order single bit continuous-time sigma-delta modulator (CT-ΣΔM). The complete interface circuit exhibits a current consumption of 2mA. The obtained smart-sensor features a reduced output data rate that is suitable for a wireless sensor network with direct transmission of the raw data to a remote base station.
This paper describes the conception, designs consideration and fabrication process of a novel MEMS microphone. The presented microphone not only uses a new architecture, the sensitive part being beams moving within the plane of the substrate, but also uses an innovative detection means with Silicon piezo-resistive nanogauges. Modelization will consider acoustic and mechanical interactions. Besides, at MEMS scale, accurate simulation of the sensor must take into account thermal and viscous boundary layers in acoustics, and we will show that the presented sensor takes benefit from these short scale effects, which leads to achieve theoretical resolution as low as 24dB.