Describe a paragraph of an article

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daryooosh

Joined Jun 15, 2019
46
Hi
I am reading "application manual for power supply noise suppression and decoupling for digital ics" from Murata (is attached).
What is meaning of this paragraph :

"We can assume that as inductance becomes greater,
impedance will become greater than the lower frequency, expanding the frequency range,
necessitating the lowering of impedance for the capacitor on the low-frequency side."

in bottom of page 11 ?

Thanks
 

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dcbingaman

Joined Jun 30, 2021
495
I will give it a shot. I think what it is saying is basically as the inductance goes up, the ability of the circuit to maintain constant current goes up. But IC chips, Digital ones especially. Have a high di/dt. In order to maintain constant voltage as the inductance goes up a larger capacitor is needed to compensate for the change in current to the load. The article just seems to say that in a rather complicated way.
 
Last edited:

dcbingaman

Joined Jun 30, 2021
495
Hi
I am reading "application manual for power supply noise suppression and decoupling for digital ics" from Murata (is attached).
What is meaning of this paragraph :

"We can assume that as inductance becomes greater,
impedance will become greater than the lower frequency, expanding the frequency range,
necessitating the lowering of impedance for the capacitor on the low-frequency side."

in bottom of page 11 ?

Thanks
The LTSpice Sim seems to be a good model where you can mess around with switching a pulse. Basically a switching power supply with no feedback, open loop. Does not regulate well. But you can changed values of L and C and watch the output voltage on R3.
 

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dcbingaman

Joined Jun 30, 2021
495
Here is output with selected components:
C10u.PNG Here it is again with C1 at 100u. 10 fold increase:

C100u.PNG

This seems like common sense to me. IMHO The article seems to me to be trying to make it more complicated than it really is.
 
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