scholarly journals A Fully Integrated 64-Channel Recording System for Extracellular Raw Neural Signals

Electronics ◽  
2021 ◽  
Vol 10 (21) ◽  
pp. 2726
Author(s):  
Xiangwei Zhang ◽  
Quan Li ◽  
Chengying Chen ◽  
Yan Li ◽  
Fuqiang Zuo ◽  
...  

This paper presents a fully integrated 64-channel neural recording system for local field potential and action potential. It mainly includes 64 low-noise amplifiers, 64 programmable amplifiers and filters, 9 switched-capacitor (SC) amplifiers, and a 10-bit successive approximation register analogue-to-digital converter (SAR ADC). Two innovations have been proposed. First, a two-stage amplifier with high-gain, rail-to-rail input and output, and dynamic current enhancement improves the speed of SC amplifiers. The second is a clock logic that can be used to align the switching clock of 64 channels with the sampling clock of ADC. Implemented in an SMIC 0.18 μm Complementary Metal Oxide Semiconductor (CMOS) process, the 64-channel system chip has a die area of 4 × 4 mm2 and is packaged in a QFN−88 of 10 × 10 mm2. Supplied by 1.8 V, the total power is about 8.28 mW. For each channel, rail-to-rail electrode DC offset can be rejected, the referred-to-input noise within 1 Hz–10 kHz is about 5.5 μVrms, the common-mode rejection ratio at 50 Hz is about 69 dB, and the output total harmonic distortion is 0.53%. Measurement results also show that multiple neural signals are able to be simultaneously recorded.

2020 ◽  
Vol 10 (1) ◽  
pp. 348 ◽  
Author(s):  
Donggeun You ◽  
Hyungseup Kim ◽  
Jaesung Kim ◽  
Kwonsang Han ◽  
Hyunwoo Heo ◽  
...  

This paper presents a low-noise reconfigurable sensor readout circuit with a multimodal sensing chain for voltage/current/resistive/capacitive microsensors such that it can interface with a voltage, current, resistive, or capacitive microsensor, and can be reconfigured for a specific sensor application. The multimodal sensor readout circuit consists of a reconfigurable amplifier, programmable gain amplifier (PGA), low-pass filter (LPF), and analog-to-digital converter (ADC). A chopper stabilization technique was implemented in a multi-path operational amplifier to mitigate 1/f noise and offsets. The 1/f noise and offsets were up-converted by a chopper circuit and caused an output ripple. An AC-coupled ripple rejection loop (RRL) was implemented to reduce the output ripple caused by the chopper. When the amplifier was operated in the discrete-time mode, for example, the capacitive-sensing mode, a correlated double sampling (CDS) scheme reduced the low-frequency noise. The readout circuit was designed to use the 0.18-µm complementary metal-oxide-semiconductor (CMOS) process with an active area of 9.61 mm2. The total power consumption was 2.552 mW with a 1.8-V supply voltage. The measured input referred noise in the voltage-sensing mode was 5.25 µVrms from 1 Hz to 200 Hz.


Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 512
Author(s):  
Binghui Lin ◽  
Mohamed Atef ◽  
Guoxing Wang

A low-power, high-gain, and low-noise analog front-end (AFE) for wearable photoplethysmography (PPG) acquisition systems is designed and fabricated in a 0.35 μm CMOS process. A high transimpedance gain of 142 dBΩ and a low input-referred noise of only 64.2 pArms was achieved. A Sub-Hz filter was integrated using a pseudo resistor, resulting in a small silicon area. To mitigate the saturation problem caused by background light (BGL), a BGL cancellation loop and a new simple automatic gain control block are used to enhance the dynamic range and improve the linearity of the AFE. The measurement results show that a DC photocurrent component up-to-10 μA can be rejected and the PPG output swing can reach 1.42 Vpp at THD < 1%. The chip consumes a total power of 14.85 μW using a single 3.3-V power supply. In this work, the small area and efficiently integrated blocks were used to implement the PPG AFE and the silicon area is minimized to 0.8 mm × 0.8 mm.


2013 ◽  
Vol 284-287 ◽  
pp. 2647-2651
Author(s):  
Zhe Yang Huang ◽  
Che Cheng Huang ◽  
Jung Mao Lin ◽  
Chung Chih Hung

This paper presents a wideband wireless receiver front-end for 3.1-5.0GHz band group-1 (BG-1) WiMedia application. The front-end circuits are designed in 0.18um standard CMOS process. The experimental results show the maximum conversion power gain is 45.5dB; minimum noise figure is 2.9dB. Input return loss is lower than -9.3dB and output return loss is lower than -6.8dB. The maximum LO conversion power is 0dBm. 3dB working frequency is 1.9GHz (3.1GHz-5.0GHz) Total power consumption is 24.3mW including LNA, mixer and all buffers. Total chip area is 1.27mm2 including dummy and pads.


2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Santosh Vema Krishnamurthy ◽  
Kamal El-Sankary ◽  
Ezz El-Masry

A CMOS active inductor with thermal noise cancelling is proposed. The noise of the transistor in the feed-forward stage of the proposed architecture is cancelled by using a feedback stage with a degeneration resistor to reduce the noise contribution to the input. Simulation results using 90 nm CMOS process show that noise reduction by 80% has been achieved. The maximum resonant frequency and the quality factor obtained are 3.8 GHz and 405, respectively. An RF band-pass filter has been designed based on the proposed noise cancelling active inductor. Tuned at 3.46 GHz, the filter features total power consumption of 1.4 mW, low noise figure of 5 dB, and IIP3 of −10.29 dBm.


Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8476
Author(s):  
Yuxuan Tang ◽  
Yulang Feng ◽  
He Hu ◽  
Cheng Fang ◽  
Hao Deng ◽  
...  

This paper presents a wideband low-noise amplifier (LNA) front-end with noise and distortion cancellation for high-frequency ultrasound transducers. The LNA employs a resistive shunt-feedback structure with a feedforward noise-canceling technique to accomplish both wideband impedance matching and low noise performance. A complementary CMOS topology was also developed to cancel out the second-order harmonic distortion and enhance the amplifier linearity. A high-frequency ultrasound (HFUS) and photoacoustic (PA) imaging front-end, including the proposed LNA and a variable gain amplifier (VGA), was designed and fabricated in a 180 nm CMOS process. At 80 MHz, the front-end achieves an input-referred noise density of 1.36 nV/sqrt (Hz), an input return loss (S11) of better than −16 dB, a voltage gain of 37 dB, and a total harmonic distortion (THD) of −55 dBc while dissipating a power of 37 mW, leading to a noise efficiency factor (NEF) of 2.66.


2021 ◽  
Vol 18 (4) ◽  
pp. 1327-1330
Author(s):  
S. Manjula ◽  
R. Karthikeyan ◽  
S. Karthick ◽  
N. Logesh ◽  
M. Logeshkumar

An optimized high gain low power low noise amplifier (LNA) is presented using 90 nm CMOS process at 2.4 GHz frequency for Zigbee applications. For achieving desired design specifications, the LNA is optimized by particle swarm optimization (PSO). The PSO is successfully implemented for optimizing noise figure (NF) when satisfying all the design specifications such as gain, power dissipation, linearity and stability. PSO algorithm is developed in MATLAB to optimize the LNA parameters. The LNA with optimized parameters is simulated using Advanced Design System (ADS) Simulator. The LNA with optimized parameters produces 21.470 dB of voltage gain, 1.031 dB of noise figure at 1.02 mW power consumption with 1.2 V supply voltage. The comparison of designed LNA with and without PSO proves that the optimization improves the LNA results while satisfying all the design constraints.


2012 ◽  
Vol 433-440 ◽  
pp. 5579-5583
Author(s):  
Ji Hai Duan ◽  
Chun Lei Kang

A fully integrated 5.2GHz variable gain low noise amplifier (VGLNA) in a 0.18μm CMOS process is proposed in this paper. The VGLAN can achieve a maximum small signal gain of 17.85 dB within the noise figure (NF) of 2.04 dB and a minimum gain of 2.04 dB with good input return loss. The LNA’s P1dB in the high gain mode is -17.5 dBm. The LAN consumes only 14.58 mW from a 1.8V power supply.


2013 ◽  
Vol 22 (02) ◽  
pp. 1250088 ◽  
Author(s):  
MERIAM BEN AMOR ◽  
MOURAD LOULOU ◽  
SEBASTIEN QUINTANEL ◽  
DANIEL PASQUET

In this paper we present the design of a fully integrated low noise amplifier for WiMAX standard with AMS 0.35 μm CMOS process. This LNA is designed to cover the frequency range for licensed and unlicensed bands of the WiMAX 2.3–5.9 GHz. The proposed amplifier achieves a wide band input and output matching with S11 and S22 lower than -10 dB, a flat gain of 12 dB and a noise figure around 3.5 dB for the entire band and from the upper to the higher frequencies. The presented wide band LNA employs a Chebyshev filter for input matching and an inductive shunt feedback for output matching with a bias current of 15 mA and a supply voltage of 2.5 V.


Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 137 ◽  
Author(s):  
Bo Gao ◽  
Xin Li ◽  
Jie Sun ◽  
Jianhui Wu

The features of high-resolution and high-bandwidth are in an increasing demand considering to the wide range application fields based on high performance data converters. In this paper, a modeling of high-resolution hybrid analog-to-digital converter (ADC) is proposed to meet those requirements, and a 16-bit two-step pipelined successive approximation register (SAR) analog-to-digital converter (ADC) with first-order continuous-time incremental sigma-delta modulator (ISDM) assisted is presented to verify this modeling. The combination of high-bandwidth two-step pipelined-SAR ADC with low noise ISDM and background comparator offset calibration can achieve higher signal-to-noise ratio (SNR) without sacrificing the speed and plenty of hardware. The usage of a sub-ranging scheme consists of a coarse SAR ADC followed by an fine ISDM, can not only provide better suppression of the noise added in 2nd stage during conversion but also alleviate the demands of comparator’s resolution in both stages for a given power budget, compared with a conventional Pipelined-SAR ADC. At 1.2 V/1.8 V supply, 33.3 MS/s and 16 MHz input sinusoidal signal in the 40 nm complementary metal oxide semiconductor (CMOS) process, the post-layout simulation results show that the proposed hybrid ADC achieves a signal-to-noise distortion ratio (SNDR) and a spurious free dynamic range (SFDR) of 86.3 dB and 102.5 dBc respectively with a total power consumption of 19.2 mW.


2020 ◽  
Vol 34 (29) ◽  
pp. 2050321
Author(s):  
Wei Wang ◽  
Hong-An Zeng ◽  
Fang Wang ◽  
Guanyu Wang ◽  
Yingtao Xie ◽  
...  

A new avalanche photodiode device applied to a visible light communication (VLC) system is designed using a standard 0.18 [Formula: see text]m complementary metal oxide semiconductor process. Compared to regular CMOS APD devices, the proposed device adds a [Formula: see text]-well layer above the deep [Formula: see text]-well/[Formula: see text]-substrate structure, and an [Formula: see text]/[Formula: see text] layer is deposited upon it. The [Formula: see text]/[Formula: see text] layer acts as an avalanche breakdown layer of the device, and an STI structure is used to prevent the edge break prematurely. The simulation results shows that the avalanche breakdown voltage is as low as 9.9 V, dark current is below [Formula: see text] A under −9.5 V bias voltage, and the 3 dB bandwidth is of 5.9 GHz. It is due to the use of the 0.18 [Formula: see text]m CMOS process-specific STI protection ring and short-circuits the connection of the deep [Formula: see text]-well/[Formula: see text]-substrate, and the dark current is reduced to be lower than two orders of magnitude compared to regular CMOS APD. Gain and noise characteristics are accurately calculated from Hayat dead-space model applied to this CMOS APD. So, this device’s gain and excess noise factor are 20 and 2.5, respectively.


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