scholarly journals Technique to Improve SNR for Sigma Delta Adcs for Audio Signals

2018 ◽  
Vol 7 (3.6) ◽  
pp. 91
Author(s):  
Ramana Murthy Dumpala ◽  
. .
Keyword(s):  
Transfer Function ◽  
Second Order ◽  
Analog To Digital Converters ◽  
Clock Frequency ◽  
Audio Signals ◽  
Sigma Delta ◽  
Feed Forward ◽  
Analog To Digital ◽  
Noise Transfer Function

A RISR architecture for Sigma-delta analog to digital converters with modified noise transfer function to obtain a better performance in terms of SNR is proposed. Cascading of two modified second order modulators are done to achieve 4th order modulator. Behavioral simulations are done to study the performance of feed-forward and the modified cascaded architecture. They are designed to operate at 1.28MHz clock frequency for audio applications (OSR of 32). It is noted that SNR of 115dB is achieved by cascading of two Modified second order RISR architectures which is 8dB more than the normal RISR architecture.  

scholarly journals Second-order sigma-delta modulator in standard cmos technology

2004 ◽  
Vol 1 (3) ◽  
pp. 37-44 ◽  
Author(s):  
Dragisa Milovanovic ◽  
Milan Savic ◽  
Miljan Nikolic
Keyword(s):  
Dynamic Range ◽  
Cmos Technology ◽  
Second Order ◽  
Clock Frequency ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Power Meter ◽  
Sampling Ratio

As a part of wider project sigma-delta modulator was designed. It represents an A/D part of a power meter IC. Requirements imposed were: SNDR and dynamic range > 50 dB for maximum input swing of 250 mV differential at 50 Hz. Over sampling ratio is 128 with clock frequency of 524288 Hz which gives bandwidth of 2048 Hz. Circuit is designed in 3.3 V supply standard CMOS 0.35 ?m technology.

scholarly journals A Novel Highly Linear Voltage-To-Time Converter (VTC) Circuit for Time-Based Analog-To-Digital Converters (ADC) Using Body Biasing

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2033
Author(s):  
Ahmed Elgreatly ◽  
Ahmed Dessouki ◽  
Hassan Mostafa ◽  
Rania Abdalla ◽  
El-sayed El-Rabaie
Keyword(s):  
Power Consumption ◽  
Software Defined Radio ◽  
Dynamic Range ◽  
Supply Voltage ◽  
Cmos Technology ◽  
The Body ◽  
Analog To Digital Converters ◽  
Clock Frequency ◽  
Analog To Digital ◽  
Operation Speed

Time-based analog-to-digital converter is considered a crucial part in the design of software-defined radio receivers for its higher performance than other analog-to-digital converters in terms of operation speed, input dynamic range and power consumption. In this paper, two novel voltage-to-time converters are proposed at which the input voltage signal is connected to the body terminal of the starving transistor rather than its gate terminal. These novel converters exhibit better linearity, which is analytically proven in this paper. The maximum linearity error is reduced to 0.4%. In addition, the input dynamic range of these converters is increased to 800 mV for a supply voltage of 1.2 V by using industrial hardware-calibrated TSMC 65 nm CMOS technology. These novel designs consist of only a single inverter stage, which results in reducing the layout area and the power consumption. The overall power consumption is 18 μW for the first proposed circuit and 15 μW for the second proposed circuit. The novel converter circuits have a resolution of 5 bits and operate at a maximum clock frequency of 500 MHz.

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