Do I want Ripple Current high or low?

[jayjr1105]

I see this value varies within several 3300uf caps. Do you want that number low as possible? It's very high on polymer caps.

[ChaosLegionnaire]

Re: Do I want Ripple Current high or low?

for capacitors, it refers to the maximum ripple current handling capacity before the capacitor goes kaput really fast. therefore, the higher the ripple current handling capacity rating, the better. there is no limit. aim for the sky. hope that clarifies it.

[jayjr1105]

Re: Do I want Ripple Current high or low?

for capacitors, it refers to the maximum ripple current handling capacity before the capacitor goes kaput really fast. therefore, the higher the ripple current handling capacity rating, the better. there is no limit. aim for the sky. hope that clarifies it.

So is there overhead with this rating? Like near a computer processor, if you replaced a capacitor with the same voltage and capacitance but went lower on ripple rating, would it be an issue? I assume it would be more of an issue in a power supply secondary side?

[PeteS in CA]

Re: Do I want Ripple Current high or low?

Well, a MB has DC-DC converters on it, basically DC input power supplies. So impedance and ripple current ratings for the input and output capacitors matter.

When you're talking about the decoupling capacitor networks for a processor, those can have current transients in the tens of amps at rates in the 100s of amps-per-microsecond. Narrowly speaking the electrolytic or polymer capacitors in the decoupling network need to be low impedance - low ESR and low ESL. But capacitors with low impedance generally have high ripple current ratings.

[RJARRRPCGP]

Re: Do I want Ripple Current high or low?

3300uF @ 10 V=Are you recapping an Asus socket 462 motherboard? (CPU runs off of +5V rail on Asus socket 462 motherboards) Or an early-one? (From the T-bird era)

[bestsystem]

Re: Do I want Ripple Current high or low?

some of them are rated at 100KHz and some are 120Hz, i don't know why they are not measured at the same frequency?

[jayjr1105]

Re: Do I want Ripple Current high or low?

3300uF @ 10 V=Are you recapping an Asus socket 462 motherboard? (CPU runs off of +5V rail on Asus socket 462 motherboards) Or an early-one? (From the T-bird era)

It's an XBOX. Original caps were something like 2800(mArms) and the new ones I've been replacing are 2200 and 2500 (ZLQ and UHV). I've been going with 10v lately because space permits the slightly wider cap while getting a boost on the ripple current rating.

[RJARRRPCGP]

Re: Do I want Ripple Current high or low?

It's an XBOX.

My buddy, has an XBox version 1x.

[PeteS in CA]

Re: Do I want Ripple Current high or low?

some of them are rated at 100KHz and some are 120Hz, i don't know why they are not measured at the same frequency?

It depends on the anticipated usage.

Modern low impedance and ultra-low impedance parts will be rated at 100KHz because the anticipated usage is power supply and DC-DC converter output capacitors. Switch frequencies vary, of course, but the datasheets typically have a graph that gives an idea of how a part's impedance varies with frequency.

120Hz rated parts tend to be general purpose or designed for bulk input capacitance for a power supply.