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249 Threads found on edaboard.com: Sigma Delta Bit

## 1 bit DAC Design for Delta-Sigma ADC

Hi Folks, I need to design a 1 bit DAC for sigma delta modulator. Can anybody please suggest me some architecture for dac design? For incremental delta sigma the dac needs to provide three state ( two states from two quantizer levels and one state for input level). How is it possible with 1 (...)

## Op Amp gain required for Sigma-Delta ADC

Hi, I need help to determine the op amp gain required to match certain ADC specifications. I need to design a delta sigma 14 bit ADC and need to find out required op-amp gain for the integrator design. Is there any certain formula to find out that

## 3-Stage Filter wit 1 Bit Input for a Delta-Sigma Modulator (MATLAB->VHDL)

Hello, I?ve got problem with my 3 Stage Filter Design in MATLAB (for a delta-sigma Modulator), it would be great if someone could help! The delta-sigma modulator has an input signal of 1kHz and wir OSR = 512 an output of 1 MHz. So I decided to do a 3 stage Filter: CIC w. 1 bit input (decimation (...)

## Pipleline ADC Latency

Hi, You are desgning the is a clocked system, so you should know after how much clock cycles the output is valid. (Just to be sure: you don't talk about delta sigma ADC?) Klaus

## Power Spectrum Simulation of a delta-sigma modulated signal

Hi everybody, I have a couple of questions about power spectral density simulation of the sigma-delta modulators. I want to see the harmonics inside the output bit-stream of the modulated signal. The details of what I did are provided at this link: I will be so thankful if you answer these questions: 1- How lo

## How does a Sigma Delta ADC work?

Hi Friends, I am wondering how sigma delta ADC's work with a 1 bit Comparator. I went through some articles and I have a rough idea of its architecture. There's a 1 bit comparator and the input is sampled many more times than the Nyquist rate. Suppose I have a 0 to 10V measuring sigma (...)

## actual output of sigma delta adc

hello all I have two queries on sigma delta ADC 1. While going through its material i found that while some show that the output of the modulator is series of 0s and 1s, some show it as series of 1 and -1. Which is correct 2. The output of decimator is shown as a discrete signal and not a digital (0 and 1). but the ADC should give a

## Sigma delta ADC small signal harmonic distortion problems

A strange phenomenon appears when I was testing my sigma delta ADC(MASH 2-1 structure, with single bit quantizer at both stages) . The small signal (10mVpeak-peak, 2.9Vpeak-peak as FS value) 1kHz sine wave is used as stimulus to the data converter and 2nd, 3rd, 4th, 5th harmonic distortions can be observed in Audio Precision measurement's (...)

## Interfacing PIC24FJ128GC006 microcontroller with Shunt

Hi, We are trying to interface Shunt 75mV at 500 Amps AD/DC load to PIC24FJ128GC006 microcontroller, Can we connect shunt directly to Micro controller CH0+ and CH0- pins or do we need any circuit in between. PIC24FJxxxGCyyy series micro controllers have inbuilt 16 bit sigma delta ADC. So considering the resolution we think that 0.1 (...)

## Need guidance understanding delta sigma conveters

I need some help understanding delta sigma data converters. Suppose I have a 16 bit delta sigma ADC, a sampling clock at 100kHz and an oversampling ratio of 64. I want to calculate samples per second. A 16 bit converter requires 2^N clocks; 65536 clocks in this case. If my sampling (...)

## using PWM as a DAC for audio output

To achieve 16 bit resolution with 44 kHz sampling rate using regular PWM, you would need about 3 GHz pwm clock. That's obviously not feasible. Some kind of sigma-delta modulation is necessary.

## Limit cycles in sigma delta ADC

Hi..... I have designed and fabricated a 16bit second order, single bit sigma delta modulator based ADC. During testing of ADC, when we apply zero volt at the input of ADC, sometimes it works fine and sometimes it gives a fixed code of 00FF (hex). Otherwise the ADC is working fine. Are these limit cycles and what is the solution?

## Help to check the simulated results for the Sigma-delta ADC

Currently, I have designed a second-order sigma-delta ADC (fin = 20kHz, fs = 5MHz). In this ADC, a 2-bit flash ADC was adopted as a quantizer, and a 2-bit DAC was inserted into the feedback signal path. The attached file is the system architecture and the simulated results. 113250 According to the output spectrum of th

## Need a paper about "16 bit 1MS/s nyquist-rate sigma-delta ADC"

Paper or Thesis information: T. Thantipwan and N. Wongkomet. "A power-optimized 16-bit 1MS/s nyquist-rate sigma-delta analog-to-digital converter", Chulalongkorn University. To be published. thank a lot ! - - - Updated - - - be badly in need of this paper!!!

## A question on first order ΔΣ modulator

Dear all, I am trying to design a single-bit first order delta-sigma ADC. The architecture that I am using is the very simple single ended ΔΣ modulator. The modulator is supposed to work for audio band signals (20-20KHz). The clock signal that is used is a 2.56MHz pulse. Therefore OSR is 64. Switches that i

## quantization Threshold computation for a first order sigma delta modulator

Hi, Is there any thumb rule to set the Quantization threshold for generating the bitstream while modeling a first order sigma delta ADC? I am trying to model a 16 bit SDM ADC with a full scale input of of 1Vrms. Thanks, Ranand

## Decimation filter and delta sigma

Hi, I'm a bit unclear about a decimation filter used in oversampling data converters. Say in a delta sigma ADC that has a sampling frequency of 64 MHz, input frequency of 1 MHZ, oversampling equal to (64MHz/(2*1) = 32), and a 1-bit internal ADC, the resolution is supposed to be 20 bits. So there would be (...)

## [Moved] what is bit- true implementation

Regarding bit true simulation using matlab: is there an "easy" way to model fixed point multiplication that will work transparantly with existing toolkits? Case in point: I recently used the delta sigma Toolbox (delsig), and it would be nice if you could run the simulation with fixed point multiply accumulate. And same question for (...)

## ADC output (Delta Sigma ADC)

Hello Everyone I am working on delta sigma ADCs in MATLAB, to equalize the amplitude of input and output I have to multiply the output by a scaling factor, anyone who has experience of ADC (using or working on ADCs) share the reason for this scaling ? and Secondly the SNR after delta sigma Modulator ~66 dB and after (...)

## how much should be the value of ENOB for n-bit ADC

Hi daer all; I have a question that for an 8-bit ADC for low-speed industrial applications what is the accepted minimum ENOB for interested bandwidth? I designed and implemented my sigma-delta ADC on FPGA; but the ENOB for lower frequencies (20hz) starts from 6.4 and for highest frequency in the bandwidth (8khz) is 4.9 are these values