What does a resistor and capacitor pulled down to ground do?

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Paul81
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Joined: Sat Mar 28, 2015 1:11 pm

What does a resistor and capacitor pulled down to ground do?

Post by Paul81 » Sat Mar 28, 2015 1:16 pm

After looking at one of the example schematics for the LM386N audio preamp - on the output in there's a cap and resistor pulled down to ground then the electrolyic cap and speaker's 8 ohm helps filters out unwanted frequency noise. I was a bit confused on why there was a ceramic cap and a resistor being pulled down to ground - is that to smooth out the ac frequency signal?

Valen
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Re: What does a resistor and capacitor pulled down to ground

Post by Valen » Sun Mar 29, 2015 10:06 am

This is what I found on this page:

https://lowvoltage.wordpress.com/2011/0 ... amplifier/
The 0.05uF capacitor and 10 ohm resistor pair from pin 5 to ground turns out to be called a “Boucherot cell” or “Zobel Network” and is used to prevent high frequency oscillations.
http://en.wikipedia.org/wiki/Boucherot_cell
http://en.wikipedia.org/wiki/Zobel_network

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