The tag has no wiki summary.

learn more… | top users | synonyms

0
votes
0answers
15 views

How to select parameters for Equivalent Time Sampling

I have a Nios system with Qsys components such as Interval timer, UART, SDRAM and some PIOs. My system specifications are DE0 Nano, Quartus 12.1 sp1, Altera monitor program. Nios II system are ...
1
vote
1answer
49 views

ADC samples half frequency

I'm using a dsPIC33F (Microchip) to sample a 555-timer signal. I've tried square, triangular, and "sinusoidal" signal shapes, but always have the same problem: the ADC samples the waveform correctly, ...
0
votes
2answers
108 views

Preparing Signal for Sampling

I want to sample a voltage signal from mains. I found the following circuit but im not sure how it works. The circuit consists of precision amplifier and a buffer which I can't make sense of, the rest ...
0
votes
3answers
64 views

Appropriate Method of Counting counts from a Quadrature Encoder

I'm using an Mbed to drive a DC motor which will follow a trapezoidal trajectory. What is the most appropriate way to determine position from the quadrature encoder? Should I use interrupts, or is ...
1
vote
1answer
56 views

Am I getting DC bandwidth correctly?

I am computing Johnson and shot noise in a DC circuit, where I have an Arduino Due sampling with "delay(100);", i.e. at 10Hz. Sampling rate and bandwidth follow Nyquist sampling theorem. According ...
1
vote
3answers
71 views

DSP Cutoff vs Sampling frequency question on low pass filter

Is it unrealistic to have a 125 MHz sampling rate with a cutoff frequency of 5 Hz? I downloaded a few filter programs and used their methods and it seems that even with thousands of taps it still ...
0
votes
2answers
37 views

Choice between Pseudo-Differential Unipolar and Pseudo-Differential Bipolar ADC Input

While reading about Pseudo-Differential Inputs for ADCs, I came across the document below from LT. Link : http://cds.linear.com/docs/en/product-selector-card/2PB_sarinputtypesfb.pdf Below are copied ...
0
votes
0answers
20 views

Time independent sampled data systems

The following discussion I'm assuming that the plant has no dynamic component and is just a constant gain, with perhaps a one or two sample delay. The closed loop system can therefore be completely ...
0
votes
2answers
44 views

Sampling Signal using microcontroller

I would like to decode a signal from a radio clock source, using an off the shelf receiver, and a microprocessor. The output of the receiver is a digital level which encodes either carrier on or ...
0
votes
1answer
40 views

ADC output level query

This query is related to my old post: ADC outputs random values to constant input I made further tests, and still struggling. The reason I made a new post is, the query is different. I am using FPGA ...
3
votes
6answers
394 views

16-bit or 24-bit converters?

I wanna build some DSP effects on, for example STM32F4 processor, with frequency 96 or 192 KHz. Are 16-bit converters (ADC and DAC) enough for that kind of operation? Can I hear a diffrence when ...
1
vote
1answer
60 views

ADC outputs random values to constant input

I am using ADC (ADS7822) from TI and I have some strange behaviour with it. Below diagram explains the voltage inputs and connections. I was reading strange values with this setup. I removed ...
0
votes
1answer
56 views

why it is hard to generate an impulse train ?

I have understood the concept of Ideal impulse sampling ,but i have struck upon the fact that practically generation of impulse train is not possible.
0
votes
0answers
46 views

Using the ADC on Cerebot mx7ck Pic32

I'm looking to use the ADC on the cerebot mx7ck (pic32) dev board to sample 3 input sine waves on three separate channels. However when I run my code, it appears as if I get the same sine wave from ...
1
vote
1answer
32 views

Source/Drain terminals in a MOSFET Sampling circuit

In a simple sampling circuit consisting of a MOS as the switch and a capacitor, how does one decide which of the terminals are source/drain? Thanks.
0
votes
0answers
15 views

Microwave frequency carriers and aperture error

In GPS and GNSS (global navigation satellite systems) engineering, one of the things we care very much about is the phase of the signal carrier. These are all microwave band signals. Typical sampling ...
0
votes
1answer
70 views

Why does my bandpass RF filter complain about Ts in Simulink?

I am doing a basic amplitude modulator, and I'm using as input signal for now a Gaussian noise generator, then I modulate it with a carrier fc=2e9Hz. When using Simulink along with a RF bandpass ...
2
votes
1answer
132 views

Simultaneous sampling of several channels with single ADC?

I am looking at this 8-channel, 18-bit and 200 ks/s ADC. The datasheet claims the sampling is done simultaneously for all the channels, but the diagram shows that there is only one ADC, so how is ...
0
votes
3answers
69 views

Sampling Rate Passband Signal

What is the maximum/minimum possible sampling rate for the signal to be full recovered for a passband signal?
12
votes
2answers
262 views

Why doesn't aliasing of broad band noise 'pile up' in the sample band?

I recently built a simulation to study sampling, the effects of aliasing and the effects of anti-aliasing filters on the sampled signal. For fundamental frequencies above the sample band it's obvious ...
3
votes
1answer
471 views

Relationship of FFT Size, Sampling Rate and Buffer Size

I am asking this question because I want to make sure I understand the relationship of FFT length, the sampling rate and the buffer size. This question is with respect to the CMSIS DSP library, ...
0
votes
1answer
100 views

Signal sampling question here please?

We have the signal \$y(t)=7\cos(wt) \$.We have \$f(s)=100~Hz\$.I need to find \$f(T)\$ and reconstruct the signal so that we wont have loss of signal. I think that we need to take \$f(T)>2f(s)\$ ...
0
votes
2answers
426 views

What is Subsampling in image processing?

I was going through some image processing document. And I came cross this term "sub sampling". What does it mean? Is it sampling again already sampled data .. ?
0
votes
1answer
112 views

Maximum signal data rate

I have a frequency signal range from 25 Khz to 35 Khz. I know that the the minimum signal sampling to assure reconstruction of the signal from the samples is 70 Khz. Would it be correct to assume ...
1
vote
2answers
164 views

Suggestions to interface a photodiode in the MHz range

The task at hand is to read the variations of incoming light at speeds up to 1 MHz, with some dynamic range capability (10-1000lx with 1% accuracy would suffice). This is to be used in a device which ...
1
vote
1answer
166 views

Choosing sampling rate according to the bandwith reponse in accelerometer datasheet

In an accelerometer's datasheet, the bandwidth response in the x and y axis is 350 Hz. There is another information related to the internal sampling rate (shown below). I don't know how these two ...
0
votes
1answer
56 views

Sampling: how to determine a “good” sampling rate based on a given filter

I assume that the sampling rate is w_s = 2w_max if we have an ideal low-pass filter that nulls frequencies whose absolute value is higher than that of w_max. Therefore, that the only reason for ...
0
votes
2answers
112 views

IF signal amplify without delay

I have a RF Frontend that has an 4 IF signal output (2 I channel and 2 Q channel from 2 receiving anettans). Each channel of the IF has a signal rangining from 1.5V to 3.5V with a DC offset of 2.5V. ...
0
votes
3answers
189 views

What's the relationship between samples and bits?

I was talking to a friend today that I have a transmitter which is capable of sending 128 samples/second. Note that each sample is a voltage level represented by a floating point decimal. He then ...
0
votes
1answer
74 views

Choosing the right sampling frequency for WLAN 802.11ac signal (BW : 80 MHz)?

I’ve got a WLAN 802.11ac signal & it’s bandwidth is 80MHz, now I would like to know the ideal sampling frequency for this signal. As per the nyquist theorem , the sampling frequency could be 160 ...
1
vote
0answers
289 views

STM32 ADC: Multiple channels with different sampling rates

I am trying to figure out how the STM32 multiple channels ADC conversion works (regular group). Lets say I want to convert on two channels, channel 1 and channel 2, on ADC1 and the sampling rates are ...
1
vote
2answers
75 views

Sampling frequency from audio jack

I want to start a project where i'll sample directly from the audio jack. Now i don't know what the sampling frequency should be. I don't know what is the maximum frequency of sound, i don't know it ...
1
vote
1answer
67 views

Nyquist Sampling rate

We have \$z(t)=\cos(100πt)\cos^2(500πt)\$ . Find Nyquist sampling rate. Well, I know that \$f_s=2f_{max}\$. My main problem is that I am not entirely sure if I could re-write the above signal as: ...
1
vote
3answers
74 views

what is the difference in u-controller processor sampling frequency and the z-domain conversion sampling frequency?

I have observed a bit confusing behavior of my system response (or may be i am missing something). I have a transfer function in S domain converted to Z domain with a 1kHz sampling frequency at the ...
-1
votes
0answers
96 views

ADC and Pre-Amp Suggestion for RBpi

I want to receive VLF signals (between 15kHz to 30kHz) with my RBPI. So I can found only this antenna: Miniature Very Low Frequency Antenna ANTM1. This miniature 6 inch long antenna can be ...
1
vote
1answer
223 views

Weird samples from SAR ADC

I am playing around with some SAR (Successive Approximation) A/D-converters. I have made a test circuit where I have a 16-bit DAC from Texas Instruments (R2R-based) and an 16-bit SAR ADC from Analog ...
1
vote
1answer
269 views

Connect VLF antenna to raspberryPi

I want to connect two VLF antenna (given below) to a RaspberryPi using it's GPIO ports with a MPC3008 ADC. Desired frequency range is between 3kHz to 30kHz, and MPC3008 supports 200,000 samples/sec ...
0
votes
1answer
179 views

Transfering audio data between two DSP's, clock sync problem

I have a system with two DSP modules. The audio is routed from DSP1 to DSP2 and then back to DSP1, which in turn immediately sends it to DAC. It's a high-quality stereo sound at 44.1KHz. This is a ...
-1
votes
1answer
389 views

pulse amplitude modulation

Im bit struggling with PAM question. I've been trying to solve this for few hours but I am stuck at the stage where I need to sample m(t). Could you please help me with detailed answers and workings. ...
1
vote
2answers
106 views

What does “two signals aliasing to each other” mean?

So I just read something that two signals are aliasing to each other. I know what a single signal is being aliased - that is when sampling rate is not higher than or equal to the Nyquist rate. But I ...
0
votes
1answer
127 views

Resampling with MSB operation

I'm new to verilog and HDL, so please be patient with me. In a code, I have an input variable clk, two input 16 bit samples, that are stored into ...
-5
votes
1answer
56 views

Understanding the concepts of sounds analysis [closed]

I'm trying to understand many concepts behind sound analysis. Here's what I'm trying to understand: What's sound & sound wave? What's sampling and hertz? And how to do sampling? (starting from ...
1
vote
1answer
616 views

why is this oscilloscope so cheap with a 20Gsa/s sampling resolution?

I've looked around this site but I haven't been able to figure out why this oscilloscope seems to have such a high sampling rate "Repetitive mode: 20GSa/S" and be relatively cheap: ...
2
votes
2answers
148 views

Understanding sampling rate and frequency of logic analysers

Below shown is the screenshot of the GUI for Saleae logic analyser http://www.saleae.com/logic I would like to know what is the meaning of "number of samples to collect" and "sample rate" ? As per ...
2
votes
1answer
72 views

How many periods of a periodic signal are required to properly determine magnitude?

I have a pure sinusoidal test function. I am trying to determine the magnitude of the response through my circuit very soon after powering up with circuit. If I am using a 1kHz test signal, I only ...
0
votes
2answers
114 views

Choosing Oscilloscope with appropriate bandwidth for Jitter analysis

Can someone give me a rule of thumb of choosing Oscilloscope with appropriate bandwidth for the Jitter analysis of clock signals? What device is highly preferable: spectrum analyzers, frequency ...
2
votes
4answers
623 views

Do digital Anti Aliasing filters exist for traditional ADCs?

I'm currently learning about Analogue to Digital Converters. From what I understand, aliasing occurs if the input signal being sampled has power above the "Nyquist frequency" of the ADC(Sampling ...
1
vote
3answers
109 views

Sampling resolution

I"m trying to buy a physiological measurements device. In the device spec they mention: Sampling freq: 2kHz Channel bandwidth: DC up-to 0.2*Fs Sampling Resolution: 24nV/bit My question is, what ...
3
votes
2answers
204 views

Sampling Theorem

$$x(t) = \frac{sin(2000\pi t)}{\pi t}cos(1000\pi t)$$ is sampled with sampling period \$T_{s} = \frac{1}{8000}\$, to obtain the sampled signal \$x_{p}(t)=x(t)p(t)\$, where \$p(t)= \sum_{n = ...
5
votes
2answers
781 views

Does Nyquist rate depend on the sampling rate?

The book Computer Networks by Andrew S Tanenbaum mentions the following (paraphrased): For a noiseless channel, Nyquist theorem states: Maximum data rate = \$2H \space log_{2} V \$ bits/sec ...