A multi-stage sigma-delta modulator based on noise-coupling and digital feed-forward techniques

2021 ◽  
Author(s):  
Habibeh Fakhraie ◽  
Tohid Moosazadeh ◽  
Reza Sabbaghi-Nadooshan ◽  
Alireza Hassanzadeh
Keyword(s):  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Feed Forward ◽  
Noise Coupling ◽  
Multi Stage

Design of Third-Order Single-Loop Full Feed-Forward Sigma Delta Modulator

2014 ◽  
Vol 609-610 ◽  
pp. 1176-1180
Author(s):  
Liang Liu ◽  
Song Chen ◽  
Chong He ◽  
Liang Yin ◽  
Xiao Wei Liu
Keyword(s):  
Model Building ◽  
Inertial Sensors ◽  
Sampling Rate ◽  
Third Order ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Feed Forward ◽  
Single Loop ◽  
Local Feedback ◽  
Sigma Delta Adc

Sigma Delta modulator is widely used in ADC for kinds of micro inertial sensors, Sigma Delta ADC can be easily integrated with digital circuits. It possesses some performances of good linearity and high accuracy, while it has no such strict requirements for the match of device dimensions. In this paper, the design of third-order Sigma Delta modulator with a structure of single-loop full feed-forward is accomplished, meanwhile it uses local feedback for zero optimization to improve the shaping capacity of the modulator noise within the signal bandwidth. The OSR (over-sampling rate) of the modulator is 128 and the signal bandwidth is 10 kHz. By the system model building and simulation in the Simulink of MATALAB, the SNR is 96.3 dB and the ENOB is 15.71 bits. Then the modulator is implemented into transistor-level circuits with 0.5um process, by the simulation in Spectre of Cadence, the SNR is 88.5 dB and the ENOB is 14.41 bits. 搜

A Fourth-Order MASH Sigma-Delta Modulator in Inertial Sensors

2013 ◽  
Vol 562-565 ◽  
pp. 311-316
Author(s):  
Xiao Wei Liu ◽  
Qiang Li ◽  
Guan Nan Sun ◽  
Wen Yan Liu
Keyword(s):  
Inertial Sensors ◽  
Signal To Noise Ratio ◽  
System Level ◽  
Noise Shaping ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Technical Requirements ◽  
System Level Simulation ◽  
Multi Stage ◽  
Multi Phase

The theory of a Sigma-Delta modulator is introduced in this paper. Based on this theory, a feedback 2-1-1 multi-stage-noise-shaping (MASH) sigma-delta modulator is designed, and the coefficients of the modulator are calculated. The system-level simulation results show that the effective number of bits (ENOB) is 24 bits when the signal bandwidth is 1 kHz and the over-sampling (OSR) rate is 128. Then the circuits of modulator are designed, including integrator, comparator, multi-phase clock and the noise cancelling logic. The whole modulator is simulated in Cadence, the signal to noise ratio (SNR) of the modulator is 125.4dB, and the ENOB is 21.1bits, which meet the technical requirements of the sensor.

A Feed-Forward Sigma-Delta Modulator Applied in Silicon Gyroscope

2015 ◽  
Vol 645-646 ◽  
pp. 657-661
Author(s):  
Qi Shao ◽  
Qiu Ye Lv ◽  
Hao Meng ◽  
Qiang Fu ◽  
Xiao Wei Liu
Keyword(s):  
Sampling Rate ◽  
Ideal Model ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Feed Forward ◽  
Single Loop ◽  
Local Feedback ◽  
Signal Band

Aiming to be applied in silicon gyroscope, a three-order single loop feedforward modulator with three-bit quantizer and local feedback is designed in this paper. Signal band is 200 KHz, sampling rate is 25.6 MHz, OSR is 64. Ideal modulator is then designed and simulated in MATLAB, getting SNR 125dB. Non-ideal factors are also added to ideal model, DWA technology is adopted to restrain the nonlinearity of multi-bit quantizer, getting SNR 104dB. Finally, transistor-level full-difference modulator is designed and simulated in Cadence, fetting SNR 101.3dB.

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