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ZengLei
Joined: 24 Jan 2006
Posts: 102
Location: WuHan China PR
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 25 Mar 2008 10:15 diode noise generator |
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How to build a simple white noise generator ?
i want to build a simple one ,so i can understand the white noise thoroughly.
any suggestions or circuitry?
thanks
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abhityagi85
Joined: 11 Jan 2008
Posts: 18
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25 Mar 2008 10:30 zener noise generator |
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every circuit is noisy, isnt it?
so u can have it 
Hey u can have a pn sequence generator and its output will be a white noise genertor depending on ur bandwidth of interest u can use it.
another is in dds, we get a signal and lots of spur, elliminate this main signal, and amplify rest
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ZengLei
Joined: 24 Jan 2006
Posts: 102
Location: WuHan China PR
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25 Mar 2008 13:49 build white noise generator |
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en~~~
i see many circuitry use the zener diode as the white noise source~~~~~
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FvM
Joined: 22 Jan 2008
Posts: 5834
Helped: 856
Location: Bochum, Germany
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25 Mar 2008 13:56 simple white noise generator |
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| PN generator is a usual method, National previously had a MOS IC with PN generator to generate white noise for audio applications. Another usual method is by amplifying the voltage of a zener diode, it is band limited due to Cd || Rd time constant, but sufficient white for audio band. I don't have my old design folder at hand, thus I can't give you a circuit with component dimensions.
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25 Mar 2008 13:56 Ads |
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rkodaira
Joined: 08 Jun 2004
Posts: 332
Helped: 54
Location: Sao Paulo - Brasil
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25 Mar 2008 14:26 white noise diode |
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Besides the idea of FvM to use the thermal noise obtained from a PN junction (and amplifying it), you should see this pseudo white noise generator using a PIC microcontroller:
http://chip.aeug.org/noise508.asm
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FvM
Joined: 22 Jan 2008
Posts: 5834
Helped: 856
Location: Bochum, Germany
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25 Mar 2008 14:44 white noise zener |
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Yes, from part count aspect, a 8 pin micro is actually unrivaled. The point is that I didn't design a noise generator since 25 years...
B.T.W.: Zener diode noise isn't thermal noise, it's shot noise amplified by avalanche effect.
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ZengLei
Joined: 24 Jan 2006
Posts: 102
Location: WuHan China PR
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26 Mar 2008 14:43 white noise generator ic |
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I got one as below:
http://www.maxim-ic.com/appnotes.cfm/an_pk/3469
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pngzhi
Joined: 20 Jan 2008
Posts: 112
Helped: 7
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29 Mar 2008 7:37 how to make a white noise generator |
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| A Psedue Noise genarator in one of the simplest ways.
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