A design for a CMOS frontend integrated circuit （chip） for neural signal acquisition working at wide voltage supply range is presented in this paper. The chip consists of a preamplifier, a serial instrumental amplif...A design for a CMOS frontend integrated circuit （chip） for neural signal acquisition working at wide voltage supply range is presented in this paper. The chip consists of a preamplifier, a serial instrumental amplifier （IA） and a cyclic analog-to-digital converter （CADC）. The capacitive-coupled and capacitive-feedback topology combined with MOS-bipolar pseudo-resistor element is adopted in the preamplifier to create a -3 dB upper cut-off frequency less than 1 Hz without using a ponderous discrete device. A dual-amplifier instrumental amplifier is used to provide a low output impedance interface for ADC as well as to boost the gain. The preamplifier and the serial instrumental amplifier together provide a midband gain of 45.8 dB and have an input-referred noise of 6.7 μVrms integrated from 1 Hz to 5 kHz. The ADC digitizes the amplified signal at 12-bits precision with a highest sampling rate of 130 kS/s. The measured effective number of bits （ENOB） of the ADC is 8.7 bits. The entire circuit draws 165 to 216 μA current from the supply voltage varied from 1.34 to 3.3 V. The prototype chip is fabricated in the 0.18-μm CMOS process and occupies an area of 1.23 mm2 （including pads）. In-vitro recording was successfully carried out by the proposed frontend chip.展开更多
In this paper, a novel technique for power amplifier (PA) linearization is presented. The Legendre wavelet neural networks (LWNN) is first utilized to model PA and inverse structure of the PA by applying practical tra...In this paper, a novel technique for power amplifier (PA) linearization is presented. The Legendre wavelet neural networks (LWNN) is first utilized to model PA and inverse structure of the PA by applying practical transmission signals and the gradient descent algorithm is applied to estimate the coefficients of the LWNN. Secondly, this technique is implemented to identify and optimize the coefficient parameters of the proposed pre-distorter (PD), i.e., the inversion model of the PA. The proposed method is most efficient and the pre-distorter shows stability and effectiveness because of the rich properties of the LWNN. A quite significant improvement in linearity is achieved based on the measured data of the PA characteristics and out power spectrum has been compared.展开更多
According to the characteristics of neural signal,a low-voltage and high-speed operational transconductance amplifier has been realized as a direct readout circuit. To reduce the size and cost of this chip, the amplif...According to the characteristics of neural signal,a low-voltage and high-speed operational transconductance amplifier has been realized as a direct readout circuit. To reduce the size and cost of this chip, the amplifier uses feedforward compensation technique without Miller capacitor. Using capacitors as a closed-loop feedback not only amplifies the neural signal, but also reduces chip power consumption by replacing the feedback resistor. Simulations were carried out with 0.18m CMOS technology, and the simulation results satisfied the requirements of neural signal.展开更多
Recent work in the field ofneurophysiology has demonstrated that, by observing the firing characteristic of action potentials （AP） and the exchange pattern of signals between neurons, it is possible to reveal the na...Recent work in the field ofneurophysiology has demonstrated that, by observing the firing characteristic of action potentials （AP） and the exchange pattern of signals between neurons, it is possible to reveal the nature of ＂memory＂ and ＂thinking＂ and help humans to understand how the brain works. To address these needs, we developed a prototype fully integrated circuit （IC） with micro-electrode array （MEA） for neural recording. In this scheme, the microelectrode array is composed by 64 detection electrodes and 2 reference electrodes. The proposed IC consists of 8 recording channels with an area of 5 x 5 mm2. Each channel can operate independently to process the neural signal by amplifying, filtering, etc. The chip is fabricated in 0.5-#m CMOS technology. The simulated and measured results show the system provides an effective device for recording feeble signal such as neural signals.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.61474107,61372060,61335010,61275200,61178051)the Key Program of the Chinese Academy of Sciences(No.KJZD-EW-L11-01)
文摘A design for a CMOS frontend integrated circuit （chip） for neural signal acquisition working at wide voltage supply range is presented in this paper. The chip consists of a preamplifier, a serial instrumental amplifier （IA） and a cyclic analog-to-digital converter （CADC）. The capacitive-coupled and capacitive-feedback topology combined with MOS-bipolar pseudo-resistor element is adopted in the preamplifier to create a -3 dB upper cut-off frequency less than 1 Hz without using a ponderous discrete device. A dual-amplifier instrumental amplifier is used to provide a low output impedance interface for ADC as well as to boost the gain. The preamplifier and the serial instrumental amplifier together provide a midband gain of 45.8 dB and have an input-referred noise of 6.7 μVrms integrated from 1 Hz to 5 kHz. The ADC digitizes the amplified signal at 12-bits precision with a highest sampling rate of 130 kS/s. The measured effective number of bits （ENOB） of the ADC is 8.7 bits. The entire circuit draws 165 to 216 μA current from the supply voltage varied from 1.34 to 3.3 V. The prototype chip is fabricated in the 0.18-μm CMOS process and occupies an area of 1.23 mm2 （including pads）. In-vitro recording was successfully carried out by the proposed frontend chip.
文摘In this paper, a novel technique for power amplifier (PA) linearization is presented. The Legendre wavelet neural networks (LWNN) is first utilized to model PA and inverse structure of the PA by applying practical transmission signals and the gradient descent algorithm is applied to estimate the coefficients of the LWNN. Secondly, this technique is implemented to identify and optimize the coefficient parameters of the proposed pre-distorter (PD), i.e., the inversion model of the PA. The proposed method is most efficient and the pre-distorter shows stability and effectiveness because of the rich properties of the LWNN. A quite significant improvement in linearity is achieved based on the measured data of the PA characteristics and out power spectrum has been compared.
基金Supported by Natural Science Foundation Project of CQ CSTC(2007BB2176)
文摘According to the characteristics of neural signal,a low-voltage and high-speed operational transconductance amplifier has been realized as a direct readout circuit. To reduce the size and cost of this chip, the amplifier uses feedforward compensation technique without Miller capacitor. Using capacitors as a closed-loop feedback not only amplifies the neural signal, but also reduces chip power consumption by replacing the feedback resistor. Simulations were carried out with 0.18m CMOS technology, and the simulation results satisfied the requirements of neural signal.
基金supported by the National Natural Science Foundation of China(No.61076118)
文摘Recent work in the field ofneurophysiology has demonstrated that, by observing the firing characteristic of action potentials （AP） and the exchange pattern of signals between neurons, it is possible to reveal the nature of ＂memory＂ and ＂thinking＂ and help humans to understand how the brain works. To address these needs, we developed a prototype fully integrated circuit （IC） with micro-electrode array （MEA） for neural recording. In this scheme, the microelectrode array is composed by 64 detection electrodes and 2 reference electrodes. The proposed IC consists of 8 recording channels with an area of 5 x 5 mm2. Each channel can operate independently to process the neural signal by amplifying, filtering, etc. The chip is fabricated in 0.5-#m CMOS technology. The simulated and measured results show the system provides an effective device for recording feeble signal such as neural signals.
