Alberto Bonanno

A Very Low-Complexity 0.3–4.4 GHz 0.004 mm

This paper presents a very low-complexity all-digital IR-UWB transmitter that can generate pulses in the band 0-5 GHz, requiring a silicon area lower than a PAD for signal I/O. The transmitter, suited to non-standardized low data rate applications, is prototyped in a 130 nm RFCMOS technology and includes analog control signals for frequency and bandwidth tuning. Center frequency is linearly selected with voltage supply, 0.5 V for the range 0-960 MHz and 1.1 V supply for the higher 3.1-5 GHz range. The architecture is based on the same delay cell for both baseband and radio frequency signal generation and pulses fractional bandwidth remains constant when voltage supply and control voltages scale. At 420 MHz center frequency, the transmitter achieves 7 pJ/pulse, and for 4 GHz center frequency pulses, it achieves 32 pJ/pulse active energy consumption. The OOK/S-OOK transmitter occupies an area of 0.004 mm2. For ASK modulation, the system includes a separate on-chip capacitor bank connected to the output of the transmitter for an overall size of 0.024 mm2. For pulse rates below 100 kpps, the generated pulses meet the FCC indoor mask with an off-chip DC block capacitor. The paper also presents over-the-air measurements using a planar monopole antenna operating in the 1.5-3.7 GHz frequency range.

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The sensing capabilities of zinc oxide nano/micro-structures have been widely investigated and these structures are frequently used in the fabrication of cutting-edge sensors. However, to date, little attention has been paid to the multi-sensing abilities of this material. In this work, we present an efficient multisensor based on a single zinc oxide microwire/gold junction. The device is able to detect in real time three different stimuli, UV-VIS light, temperature and pH variations. This is thanks to three properties of zinc oxide its photoconductive response, pyroelectricity and surface functionalization with amino-propyl groups, respectively. The three stimuli can be detected either simultaneously or in a sequence/random order. A specific mathematical tool was also developed, together with a design of experiments (DoE), to predict the performances of the sensor. Our micro-device allows reliable and versatile real-time measurements of UV-VIS light, temperature and pH variations. Therefore, it shows great potential for use in the field of sensing for living cell cultures.

All-Digital Ultra-Wide-Band Pulsed Transmitter for Energy Detection Receivers

We report design and measurements on a 0.13 μm CMOS Schmitt Trigger-based quasi-digital resistance-to-frequency converter prototype that can be effectively used as a read-out circuit for nanodevice-based sensors. The readout circuit comprises an operational amplifier and an inverting Schmitt Trigger, achieving an hysteresis scaled to 1 mV-order, hence, increasing frequency compared to a standard Schmitt Trigger RC oscillator. Experimental results obtained through an opto-isolated PCB set-up show maximum 0.8% RL measurement accuracy and a dynamic range between 50 kΩ and 3 GΩ . The flexible R-to-F converter occupies ~ 0.005 mm2 silicon area and has a simulated power consumption of 142 μW at 1.2 V supply.

One-Dimensional ZnO/Gold Junction for Simultaneous and Versatile Multisensing Measurements

This paper presents a low-power system conceived for the integration and measurement of a nanowire (NW)-based sensor array onto a 130-nm CMOS technology process. Each array element includes a dielectrophoresis (DEP) signal generator for NWs alignment and a quasi-digital read-out circuit (ROC) for impedance conversion. The two subsystems can be digitally controlled by an external microcontroller which reads the ROC output and calculates the resistance and capacitance of the NW. Measurements show that the integrated two-quadrants quasi-digital ROC covers the range 1 MΩ-1Ω G and 100 fF-1 μF with a signal-to-noise ratio ≥44.89 dB. The CMOS system can be considered a building block for the implementation of a complete NW-based sensing array and each element, including both DEP and ROC subsystems, occupies an active area of 0.008 mm2 and only consumes 14.76 μW during read-out phase. The ROC has been also validated using an off-chip nanogapbased nanodevice integrating a single ZnO-NW which has been used as ultraviolet (UV) sensor during experiments. The device has been stimulated by an external UV source providing an irradiance ≥93 μW/cm2 to the nanodevice surface. We have proved that the ROC is able to measure the ZnO-NW electrical characteristics and their variations due to the photogenerated charge carriers.

A

This paper extends Average Threshold Crossing (ATC) wireless transmission to a multi-channel case by using Address-Event Representation (AER) as the way to convey information. This is encoded in the timings of the transmitted packets which in turn carry the identifier of the event source. By integrating a Impulse RadioUltra Wide Band (IR-UWB) and choosing the proper protocol and modulation, we can aim to minimize the power consumption and provide error detection. The whole system, fully asynchronous, has been implemented in a full-custom chip; besides having multiple independent inputs, it can be configured both to deploy a multi-chip system (with a single receiver) and to optimize wireless transmission parameters. The paper concludes with additional theoretical simulations on the ATC scheme to justify further analyses for our specific application area which regards movement recognition.

0.13~\mu{\rm m}

The design of a wireless data-glove is introduced in this paper, the aim is to provide an effective and complete solution wherever a tactile sensing system has to be integrated to correctly interact with the surrounding environment (e.g., astronauts extravehicular activity glove). The focus is on the design of the whole system, starting with the readout circuit, the digital signal encoding and ending with the data transmission. The system is made of eight quasi-digital readout circuits to convert the analog information into a pulse-density modulation. The pulse streams are then temporally ordered to form a single streams of events. By integrating a Impulse Radio Ultra-Wide Band (IR-UWB) transmitter and choosing the proper protocol and modulation, we can aim to minimize the power consumption and provide error detection, the design has also taken into account the minimization of the complexity of the receiver. The whole system, fully asynchronous, has been designed as a single full-custom chip, besides having multiple independent inputs, it can be configured both to deploy a multi-chip system (with a single receiver) and to optimize wireless transmission parameters.

CMOS Operational Schmitt Trigger R-to-F Converter for Nanogap-Based Nanosensors Read-Out

This paper describes the Micro-for-Nano (M4N) approach as effective solution to overcome challenges related to the nanomaterial assembly with electrodes, the low-noise measurement of nanomaterial electrical properties and the CMOS design of the nanosensor electronic interface. This paper presents both the fabrication process of a nanodevice onto the IC surface using Dielectrophoresis (DEP) and the Read-Out Circuit (ROC) used for the inspection of the electrical properties of nanowires (NW). The ROC includes a Time-over-Threshold circuit which has been characterized stand-alone. It shows maximum measurement error of 0.8% with a maximum linearity error below 1.86% in the range 300kΩ-100MΩ. The ROC occupies 0.0067 mm2 silicon area and simulation data shows that the maximum power consumption is 8.9μW at 1.2 V. The paper presents first measurement results obtained on fabricated prototype chips based on ZnO-NW.

A Low-Power 0.13-

Digital filters implement a continuos computation and therefore generally they do not exhibit any structural idleness. This can prevent the usage of classical low-power optimizations that exploit idleness, such as clock gating. In this work, we propose a data-driven implementation of clock gating for digital filters, which relies on the observation that often times the dynamic range of the inputs uses only a small portion of the bidwith, resulting in most of the higher-order bits of the registers having very low switching activity. When this occurs, unused bits in each filter tap can be clock-gated; since all the gated flip-flops share the same idle condition (i.e., new and currently stored are identical) they can share a single clock gating cell. The number of flip-flops that can be gated with a single cell depends on the tradeoff between the power saved and the performance penalty. This technique has been applied on a digital filter used within an ultra low-power industrial design; comparison with other standard and advanced automatic clock-gating methods highlights the effectiveness of the proposed technique.

\mu \text{m}

We present a fully asynchronous threshold-based IR-UWB receiver which enables a high sensitive distance estimation. It includes an ultra-low power baseband unit which achieves 533 fJ/pulse with an asynchronous, multipath robust and time expiring energy detector, which embeds signal strength in the baseband processing latency to increase sensitivity to TX-RX separation. Asynchronous line-of-sight over-the-air measurements obtained with an integrated all-digital transmitter show a maximum sensitivity of 1mm TX-RX separation per nanosecond system latency. The RX also permits data communication based on the use of self-synchronized modulations.

CMOS IC for ZnO-Nanowire Assembly and Nanowire-Based UV Sensor Interface

This paper presents a customizable sensing system based on functionalized nanowires (NWs) assembled onto complementary metal oxide semiconductor (CMOS) technology. The Micro-for-Nano (M4N) chip integrates on top of the electronics an array of aluminum microelectrodes covered with gold by means of a customized electroless plating process. The NW assembly process is driven by an array of on-chip dielectrophoresis (DEP) generators, enabling a custom layout of different nanosensors on the same microelectrode array. The electrical properties of each assembled NW are singularly sensed through an in situ CMOS read-out circuit (ROC) that guarantees a low noise and reliable measurement. The M4N chip is directly connected to an external microcontroller for configuration and data processing. The processed data are then redirected to a workstation for real-time data visualization and storage during sensing experiments. As proof of concept, ZnO nanowires have been integrated onto the M4N chip to validate the approach that enables different kind of sensing experiments. The device has been then irradiated by an external UV source with adjustable power to measure the ZnO sensitivity to UV-light exposure. A maximum variation of about 80% of the ZnO-NW resistance has been detected by the M4N system when the assembled 5 μm × 500 nm single ZnO-NW is exposed to an estimated incident radiant UV-light flux in the range of 1 nW–229 nW. The performed experiments prove the efficiency of the platform conceived for exploiting any kind of material that can change its capacitance and/or resistance due to an external stimulus.