# Capacitor selection from Linear Technology generated design

I'll preface this by saying I'm a SW Engineer. I've used the Linear Technologies Software to design a step down DC power supply from 12V to 6V. The package has given me a design but I'm a tad confused by the output capacitors given by the design.

The first output cap is a ceramic but is illustrated on the design as polarised. I thought ceramic caps weren't bothered with positive and negative connections. On top of that the spec for the cap is 10uF, ESR = 5M, and ESL = 0.3nH.

The second "Output Bulk Cap" is polarised, but I assume it can be electrolytic, and has values of 100uF, ESR = 15M and ESL = 1nH.

I normally do my shopping at Farnell's UK site and can't figure out what I need as there's nothing that comes close to 5 Mega Ohm ESR. Am I looking for a special type of cap which I'm not familiar with? I'd be very grateful for any pointers.

EDIT - this is the circuit: -

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As a note, series inductances are generally very slow for these components (i.e. 300 pH as shown); you need to be more concerned about the stray inductance in your traces. ESR means Equivalent Series Resistance, which, along with inductance, is a non-ideal characteristic due to subsequent power losses. Such devices known as super capacitors have ultra-low ESR values. –  sherrellbc Jun 13 at 17:24