A 2nd-Order Continuous Time Delta-Sigma Modulator for Photoplethysmography Analog Front-End

2020 ◽  
Author(s):  
Eka Fitrah Pribadi ◽  
Rajeev Kumar Pandey ◽  
Paul C.-P. Chao
Keyword(s):  
Transfer Function ◽  
Continuous Time ◽  
Supply Voltage ◽  
Signal To Noise Ratio ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Delta Sigma Modulator ◽  
Delta Sigma ◽  
Low Pass ◽  
Order Continuous

Abstract A brief presents a 2nd order continuous-time delta-sigma modulator (CT-DSM) using a low pass filter to reduce the slew rate requirement of the output swing of the first integrator. By adding the low pass filter, the desired transfer function of the CT-DSM is altered. Thus a feed-forward based compensation circuit is introduced to transform the altered transfer function to the original condition. The CT-DSM is designed with a bandwidth of 100 Hz to satisfy the requirement of photoplethysmogram (PPG) detection. The CT-DSM is simulated using CMOS 180 nm technology with the layout area 460 μm × 460 μm. The circuit uses a 1.8 V supply voltage and consumes 35.61 μW. The signal-to-noise ratio of the CT-DSM is 101.2 dB, while the SFDR is 99.1 dB.

Design of Programmable Wideband Low Pass Filter with Continuous-Time/Discrete-Time Hybrid Architecture

2017 ◽  
Vol E100.C (10) ◽  
pp. 858-865 ◽  
Author(s):  
Yohei MORISHITA ◽  
Koichi MIZUNO ◽  
Junji SATO ◽  
Koji TAKINAMI ◽  
Kazuaki TAKAHASHI
Keyword(s):  
Discrete Time ◽  
Continuous Time ◽  
Hybrid Architecture ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

ANALYSIS AND IMPROVEMENT TECHNIQUES FOR THE TRANSFER FUNCTION OF A PLANAR LOW - PASS FILTER

2016 ◽  
Vol 15 (12) ◽  
pp. 2579-2586
Author(s):  
Adina Racasan ◽  
Calin Munteanu ◽  
Vasile Topa ◽  
Claudia Pacurar ◽  
Claudia Hebedean
Keyword(s):  
Transfer Function ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

A Low Power Low-Pass Fourth-Order Filter for WiMAX/LTE Receiver in CMOS 45nm Technology

2016 ◽  
Vol 26 (03) ◽  
pp. 1750048 ◽  
Author(s):  
Vida Orduee Niar ◽  
Gholamreza Zare Fatin
Keyword(s):  
Low Power ◽  
Fourth Order ◽  
Supply Voltage ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Power Filter ◽  
Order Filter ◽  
Source Follower ◽  
Low Pass ◽  
Circuit Technique

In this paper, a [Formula: see text]-[Formula: see text] low-pass and low power filter with tunable in-band attenuation for WiMAX/LTE receiver is presented. The fourth-order filter consists of two cascaded biquad stages. The source-follower (SF) stage is used as a key building block in these biquads. In this paper, we have presented a circuit technique to reduce the nonlinearity of the SF stage resulting from unmatched signal swings at the gate and source terminals of the input transistor. The proposed SF stage, is used for design of a linear biquad which is then utilized in a fourth-order Butterworth low-pass filter. The simulation results of the filter for bandwidth of 10 MHz show that the IIP3 of the filter is equal to 8.22[Formula: see text]dBm, in-band noise density is 100[Formula: see text]nV/[Formula: see text]Hz and power consumption is 5.9[Formula: see text]mW. The supply voltage of the filter is equal to 1[Formula: see text]V.

A Wideband Continuous Time Quadrature Delta Sigma Modulator Based on a Real DSM for Low Power WLAN Receiver

2017 ◽  
Vol 27 (03) ◽  
pp. 1850044 ◽  
Author(s):  
Alireza Shamsi ◽  
Esmaeil Najafi Aghdam
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Continuous Time ◽  
Signal To Noise Ratio ◽  
System Level ◽  
Complex Coefficient ◽  
Loop Filter ◽  
Delta Sigma Modulator ◽  
Delta Sigma ◽  
Excess Loop Delay

Power consumption and bandwidth are two of the most important parameters in design of low power wideband modulators as power consumption is growing with the increase in bandwidth. In this study, a multi bit wideband low-power continuous time feed forward quadrature delta sigma modulator (CT-FF-QDSM) is designed for WLAN receiver applications by eliminating adders from modulator structure. In this method, a real modulator is designed and its excess loop delay (ELD) is compensated, then, it is converted into a quadrature structure by applying the complex coefficient to loop filter. Complex coefficients are extracted by the aid of a genetic algorithm to further improve signal to noise ratio (SNR) for bandwidth. One of the disadvantages of CT-FF-QDSM is the adders of loop filters which are power hungry and reduce the effective loop gain. Therefore, the adders have been eliminated while the transfer function is intact in the final modulator. The system level SNR of the proposed modulator is 62.53[Formula: see text]dB using OSR of 12. The circuit is implemented in CMOSTSMC180nm technology. The circuit levels SNR and power consumption are 54[Formula: see text]dB and 13.5[Formula: see text]mW, respectively. Figure of Merit (FOM) obtained from the proposed modulator is about 0.824 (pj/conv) which is improved (by more than 40%) compared to the previous designs.

scholarly journals Audio Watermarking Combined with Compressive Sampling Based on QIM and DST-QR Techniques

2019 ◽  
Vol 19 (1) ◽  
pp. 20
Author(s):  
Irma Safitri ◽  
Gelar Budiman ◽  
Arfidianti Kartika Meiza Putri
Keyword(s):  
Signal To Noise Ratio ◽  
Transformation Process ◽  
Compressive Sampling ◽  
Audio Watermarking ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Digital Copyright ◽  
Sine Transform ◽  
Low Pass ◽  
Speed Change

Abuse is not only done to copy or distribute data but also to the digital copyright labels. There is a way to protect data by inserting or hiding a piece of certain information, namely a watermarking technique. In this paper, we propose audio watermarking with Quantization Index Modulation (QIM) method as an embedding process combined with Compressive Sampling (CS), Discrete Sine Transform (DST) and QR decomposition. Binary image is used as a watermark inserted in host audio. DST is used for transformation process from time domain to frequency domain, while QR is used to decompose onedimension matrix into two-dimension matrix. Meanwhile, CS is used to obtain the compressed watermark file which is done before the embedding process. QIM method is used to embed the watermark file to the audio host file. Simulation results indicated that the proposed audio watermarking technique has good robustness against some attacks such as Low Pass Filter (LPF), resampling and linear speed change. In addition, it provides good performance in terms of imperceptibility with Signal to Noise Ratio (SNR) > 20 dB and capacity C = 689 bps.

scholarly journals Study of modular transfer function-based optieal low-pass filter evaluation model and experiment

2008 ◽  
Vol 57 (5) ◽  
pp. 2854
Author(s):  
Qi Xun-Jun ◽  
Lin Bin ◽  
Cao Xiang-Qun ◽  
Chen Yu-Qing
Keyword(s):  
Transfer Function ◽  
Evaluation Model ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass
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