## Forums

## I/Q Mixing

inWhy is I/Q mixing done in receivers prior to the ADC rather than using a single mixer and converting to complex from a real data stream. Is...

Why is I/Q mixing done in receivers prior to the ADC rather than using a single mixer and converting to complex from a real data stream. Is there some aspect of the signal that is lost if the signal is not down converted with an I/Q local oscillator? -- Rick C

## Signal mixing on a delta-sigma ADC

inI have a delta-sigma ADC with exposed modulator input pin. Its definition is as follows: "Modulator Input is used to dynamically control the...

I have a delta-sigma ADC with exposed modulator input pin. Its definition is as follows: "Modulator Input is used to dynamically control the polarity of the signal in the modulator. Polarity is inverted when ?mi? input is high. This input signal allows the user to modulate the input signal with an independent clock to act as a signal mixer." OK, I can see what happens if the modulato

## Applications for low-latency closed-loop control

inFolks, This is a question about applications of technology rather than how to design it. An existing application includes an ADC/floating-point...

Folks, This is a question about applications of technology rather than how to design it. An existing application includes an ADC/floating-point processor/DAC controller to provide a closed-loop solution for emulating physical circuit characteristics up to say 100KHz. The closed-loop controller was required to have an effectively negligible delay (say 200ns) up to at least that frequen

## Learning Complicated Integrals from a Simple Integral in mathHandbook.com

inLearning Complicated Integrals from a Simple Integral just define one integral of f(x) is f(x) - x, it will know not only the...

Learning Complicated Integrals from a Simple Integral just define one integral of f(x) is f(x) - x, it will know not only the integral of f(x), but also f(x+1), 2*f(2*x+2), etc. IN: integrate(f(x_), x_) := f(x) - x; integrate(2*f(x+1)) OUT: 2*f(x+1) - 2*(x+1) reference math handbook www.mathHandbook.com

## Fractional Calculus

inWhy do we need it? http://mathhandbook.com/

Why do we need it? http://mathhandbook.com/

## Estimating transfer function with real poles, complex zeros

inHello, I find it pretty hard to estimate the poles and zeros of the following transfer function: https://snag.gy/LOJA3Q.jpg The raw CSV...

Hello, I find it pretty hard to estimate the poles and zeros of the following transfer function: https://snag.gy/LOJA3Q.jpg The raw CSV data is available here https://pastebin.com/ZBshB6eC (first/third column: frequency in Hz, second column: magnitude in dB, fourth col: angle in deg). It comes from a circuit simulator (ac analysis) and I want to use it with a high level simulation ...

## [OT] I got a JOB!!!

inSince this is a newsgroup, and this is news... Wescott Design Services is going into remission, while I pursue a day job. Job title is...

Since this is a newsgroup, and this is news... Wescott Design Services is going into remission, while I pursue a day job. Job title is Software Designer 5 at Planar Systems -- so any circuit design or control systems jones will have to be satisfied by hobby work or on the side. In the near term I'll be finishing up current work with current customers; in the longer term I'll probabl...

## Stability in PID Controllers

inI know next-to-nothing about this topic, but the following question has popped into my mind several times. It seems like folks generally (and...

I know next-to-nothing about this topic, but the following question has popped into my mind several times. It seems like folks generally (and perhaps this is totally wrong) design PID controllers by basically selecting what they think are "good" constants for the proportional, integral, and derivative terms. That is, they just sorta play with their systems and tweak the terms until it seem...

## Geometric Algebra

inI think this set of 6 introductory videos on geometric algebra is neat. https://youtu.be/srwoPQfWWS8?list=PLLvlxwbzkr7igd6bL7959WWE7XInCCevt

I think this set of 6 introductory videos on geometric algebra is neat. https://youtu.be/srwoPQfWWS8?list=PLLvlxwbzkr7igd6bL7959WWE7XInCCevt

## Recreating Undersampled Data

inI've got a situation coming up that I'm trying to think through in advance. I'm running an ADC at let's say 1 Msps, sampling an input waveform...

I've got a situation coming up that I'm trying to think through in advance. I'm running an ADC at let's say 1 Msps, sampling an input waveform that is known to be a triangle wave at roughly 2 1/16 MHz. So with every ADC sample I advance across the input waveform by about 22.5 degrees, having missed a bit along the way. And I acquire that data and now I'm looking at it offline, and I'd...

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