Capacitor with low ESR

Hey everyone,

I need a low ESR capacitor for my design (less than 500 Milli-ohms), however surprisingly enough when I went onto Mouser or Digikey sites, there was no filter for that parameter. Does anyone know where I can find a 1206 (3 x 1.6 mm), 1uF Cap, with less than 500 milli-ohms of ESR, and a voltage rating of at least 50V?

Thanks

ESR scales with capacitor size (body measurements). So you will need to choose a smaller size.

It might be necessary that you split your cap in two. One small cap (capacitance and size) for the high frequencies (low esr) and one large cap for the low frequencies. (If you split it in two make sure your larger cap has a high esr as otherwise you will get an additional resonance frequency. That is where tantal caps come in handy.)

If you need such a low esr it might be necessary to also take the board traces into consideration.

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I am going by the datasheets’ recommendation of just one 1uF cap. My problem is not what cap to choose that is already solved. I need one cap of 1uF. That’s it. My problem is 100% technical. I need to find one. But there are no filters for this when choosing one on the sites. What I am sking basically is how do I see this parameter about these caps? Can someone just find me the capacitor I need and post the link here? I seriously need this ASAP.

Post the datasheet link I don’t think it says one physical capacitor.

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You are wrong. Here it is:

ADP1720.pdf (363.4 KB)

There you go. http://www.farnell.com/datasheets/2091858.pdf?_ga=2.158044728.345100839.1527592072-1839495194.1527592072

ESR @10MHz ~10 milli Ohm (See page 2 bottom right graph)

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Download the Evaluation kit PDF … There you get your BOM

You guys don’t get it:

I need a capacitor of 1uF, with 50V voltage rating, size 1206, and ESR less than 500m Ohms.

In the Digikey site there are filters: One of the filters is for size another is for Voltage rating, another for Capacitance, but there is no filter for ESR!

Can someone send me a link for either a Digikey page or a Mouser page with a specific capacitor that fulfills all the requirements INCLUDING the ESR one? Because I don’t know how?!

Thanks

Let me guess. You designed your pcb before you started to look what you can buy. Well surprise physical size plays a role in some specifications.
The one in the evaluation kit is a 0805. With a bit of luck you can handsolder it onto the 1206 pads.

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It did have a graph showing ESR.

Why are you looking for 50V or more for the output cap?

X5R or X7R dielectrics with a voltage rating of 6.3 V or 10 V are
recommended for the output capacitor.

A minimum of 1 μF capacitance with an ESR of 500 mΩ or less is recommended to ensure stability of the ADP1720.

1uF is the minimum, larger values give better transient response.

50V is for the input cap. The output cap may be less but I am discussing the input cap. It’s in the datasheet.

Who cares what the ESR is for the input cap? :smirk:

I just need to know what cap to buy.

Why are you looking at 10MHz. Also I need a link to buy this. Where did you get it from? Was it Digikey? Was it Mouser?

You guy don’t read the posts… If you download the evaluation board PDF you get its BOM = bill of materials… A list of what to buy to produce your pcb.

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I already have my PCB made with 1206 caps.

Then no, we don’t know. :roll_eyes:

Then search for a capacitor of the same family found in the evaluation board and look for the fp size you need.

Seriously? All this time for nothing? What did I ask for? A link. Noone gave me a link. is it that hard? Come on. Stop being lazy. I mean a link from Mouser or Digikey.

Do your homework guy!