Mu-tron power filtering cap

[Diynot]

Ordering parts for a Lumitron and just need a gut check on this rather odd value mlcc (C15 470nf) called for in the power section

Is that extra (and seemingly negligible) capacitance really necessary when it is in parallel with the 10uf electro? Does the nature of an mlcc offer some superior filtering for the 1054, or can I just bump the value of C14 and avoid having to track down this part (yes mouser and Tayda have it, but I have no desire to place an order for a single capacitor)? For what it is worth, the Moo-Tron from fuzzdog does not have this, but does use a 7660

 

[lowpitch]

I'm guessing the value of C15 is not that critical and it's more about the properties of MLCCs compared to electrolytics, i. e. lower ESR and ESL for better performance at high frequencies, reduced ripple, etc.

 

[Diynot]

I'm guessing the value of C15 is not that critical and it's more about the properties of MLCCs compared to electrolytics, i. e. lower ESR and ESL for better performance at high frequencies, reduced ripple, etc.

Maybe I will just throw a 100nf 220nf or 1uf there since I have those on hand

 

[lowpitch]

Maybe I will just throw a 100nf 220nf or 1uf there since I have those on hand

That should be fine!

 

[aion]

All correct - they work better in parallel, with each type of capacitor offsetting the weaknesses of the other. But it doesn't need to be exactly 470n by any means.

 

[Diynot]

All correct - they work better in parallel, with each type of capacitor offsetting the weaknesses of the other. But it doesn't need to be exactly 470n by any means.

Awesome! Thanks for the reply. I forgot that I had seen you around these parts recently.

 

[drew.spriggs]

Use whatever ceramic over about 47n you've got available - these aren't anywhere near as necessary now with better electrolytic construction as they used to be