A 36 µW 1.1 mm2 reconfigurable analog front-end for cardiovascular and respiratory signals recording

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThis paper presents a 1.2 V 36 µW reconfigurable analog front-end (R-AFE) as a general-purpose low-cost IC for multiple-mode biomedical signals acquisition. The R-AFE efficiently reuses a reconfigurable preamplifier, a current generator (CG), and a mixed signal processing unit, having an area of 1.1 mm2 per R-AFE while supporting five acquisition modes to record different forms of cardiovascular and respiratory signals. The R-AFE can interface with voltage-, current-, impedance-, and light-sensors and hence can measure electrocardiography (ECG), bio-impedance (BioZ), photoplethysmogram (PPG), galvanic skin response (GSR), and general-purpose analog signals. Thanks to the chopper preamplifier and the low-noise CG utilizing dynamic element matching, the R-AFE mitigates 1/f noise from both the preamplifier and the CG for improved measurement sensitivity. The IC achieves competitive performance compared to the state-of-the-art dedicated readout ICs of ECG, BioZ, GSR, and PPG, but with approximately 1.4×-5.3× smaller chip area per channel.Peer ReviewedPostprint (author's final draft

A neural probe with up to 966 electrodes and up to 384 configurable channels in 0.13 μm SOI CMOS

In vivo recording of neural action-potential and local-field-potential signals requires the use of high-resolution penetrating probes. Several international initiatives to better understand the brain are driving technology efforts towards maximizing the number of recording sites while minimizing the neural probe dimensions. We designed and fabricated (0.13-μm SOI Al CMOS) a 384-channel configurable neural probe for large-scale in vivo recording of neural signals. Up to 966 selectable active electrodes were integrated along an implantable shank (70 μm wide, 10 mm long, 20 μm thick), achieving a crosstalk of −64.4 dB. The probe base (5 × 9 mm2) implements dual-band recording and a 1

An artificial iris ASIC with high voltage liquid crystal driver and 10nA light range detector and 40nA blink detector for LCD flicker removal

In a functional eye, the iris controls the pupil diameter to regulate the exposure of the retina. While iris deficiencies such as aniridia or leiomyoma can be mitigated with fixed or adaptive artificial irises [1] and adaptive transparency glasses exist to alleviate this situation, they do not mimic the normal functionality of the natural iris. To address this, a fully encapsulated, self-contained artificial iris embedded in a smart contact lens is proposed. A control ASIC is developed in 0.18 μm 16 V BCD TSMC with typ. 1.9 μw current consumption from 3 V supply voltage at office light condition

Time Multiplexed Active Neural Probe with 678 Parallel Recording Sites

We present a high density CMOS neural probe with active electrodes (pixels), consisting of dedicated in-situ circuits for signal source amplification. The complete probe contains 1356 neuron size (20x20 μm2) pixels densely packed on a 50 μm thick, 100 μm wide and 8 mm long shank. It allows simultaneous highperformance recording from 678 electrodes and a possibility to simultaneously observe all of the 1356 electrodes with increased noise. This considerably surpasses the state of the art active neural probes in electrode count and flexibility. The measured action potential band noise is 12.4 μVrms, with just 3 μW power dissipation per electrode amplifier and 45 μW per channel (including data transmission)

Time Multiplexed Active Neural Probe with 1356 Parallel Recording Sites

We present a high electrode density and high channel count CMOS (complementary metal-oxide-semiconductor) active neural probe containing 1344 neuron sized recording pixels (20 µm × 20 µm) and 12 reference pixels (20 µm × 80 µm), densely packed on a 50 µm thick, 100 µm wide, and 8 mm long shank. The active electrodes or pixels consist of dedicated in-situ circuits for signal source amplification, which are directly located under each electrode. The probe supports the simultaneous recording of all 1356 electrodes with sufficient signal to noise ratio for typical neuroscience applications. For enhanced performance, further noise reduction can be achieved while using half of the electrodes (678). Both of these numbers considerably surpass the state-of-the art active neural probes in both electrode count and number of recording channels. The measured input referred noise in the action potential band is 12.4 µVrms, while using 678 electrodes, with just 3 µW power dissipation per pixel and 45 µW per read-out channel (including data transmission)

A 70 pJ/Pulse Analog Front-End in 130 nm CMOS for UWB Impulse Radio Receivers

This paper presents an integrated ultra-low power analog front-end (AFE) architecture for UWB impulse radio receivers. The receiver is targeted towards applications like wireless sensor networks typically requiring ultra energy-efficient, low data-rate communication over a relative short range. The proposed receiver implements pulse correlation in the analog domain to severely relax the power consumption of the ADCs and digital backend. Furthermore a fully integrated prototype of the analog front-end, containing a PLL, programmable clocking generator, analog pulse correlator, a linear-in-dB variable gain amplifier and a 4-bit ADC, is demonstrated. Several design decisions and techniques, like correlation with a windowed LO instead of with a matched template, exploiting the duty-cycled nature of the system, operation in the sub-1 GHz band as well as careful circuit design are employed to reach ultra-low power consumption. The analog front-end was manufactured in 130 nm CMOS and the active circuit area measures 1000 μ m× 1500 μm. A maximum channel conversion gain of 50 dB can be achieved. Two symbol rates, 39.0625 Mpulses per second (Mpps) and 19.531 Mpps are supported. The AFE consumes 2.3 mA from a 1.2 V power supply when operating at 39.0625 Mpps. This corresponds to an energy consumption of 70 pJ/pulse. A wireless link over more than 10 m in an office-like environment has been demonstrated at 19.531 Mpps with a PER< 1E-3 under direct LOS conditions. © 2006 IEEE.status: publishe

A Reconfigurable, 130 nm CMOS 108 pJ/pulse, Fully Integrated IR-UWB Receiver for Communication and Precise Ranging

This paper presents a fully integrated flexible ultra-low power UWB impulse radio receiver, capable of cm-accurate ranging. Ultra-low-power consumption is achieved by employing the quadrature analog correlating receiver architecture, by exploiting the duty-cycled nature of the system, by operating in the sub-1 GHz band as well as by careful circuit design. Two pulse rates, 39.0625 Mpulses per second (Mpps) and 19.531 Mpps, and a wide range of processing gains (0-18 dB) are supported. Also, the acquisition algorithm and accuracy can be adapted at run time. This flexible implementation allows to dynamically trade power consumption for performance depending on the operating conditions and the application requirements. The receiver prototype was manufactured in 130 nm CMOS and the active circuit area measures 4.52mm2. The IC contains a complete analog front-end, digital backend and implements the algorithms necessary for acquisition, synchronization, data reception and ranging. Consuming 4.2 mW when operating at 39.0625 Mpps, it achieves an energy efficiency of 108 pJ/pulse. A 1.3 Mb/s wireless link over more than 10 m in an office-like environment has been demonstrated under direct line-of-sight (LOS) conditions with a raw packet-error-rate (PER) less than 10% and cm-accurate ranging. © 2009 IEEE.status: publishe

A 0.6-V, 0.015-mm2, time-based ECG readout for ambulatory applications in 40-nm CMOS

© 2016 IEEE. A scalable time-based analog front end in 40-nm CMOS is presented for ECG readout for ambulatory applications. The main challenge addressed is achieving a large dynamic range readout (necessary to handle large signals during motion) in a power and area-efficient manner at low voltage supplies while also tackling the challenges of increase in flicker noise and gate-leakage current. Demonstrated results show a significant improvement in ac-dynamic range without compromising on area (0.015 mm2) and power consumption (3.3∼ μW). This paper will be relevant toward developing low-cost, low-power sensor system-on-chips required for wearable biomedical applications.status: publishe