When to Choose ZL vs. MCZ

[bgavin]

The Rubycon ZL data sheet bills this part as High Ripple/Low Impedance. The MCZ is the top of the line low ESR product. I have ZL on both system boards, and in power supplies.

Question: is there a criteria to use for choosing between ZL and MCZ?

[kc8adu]

Re: When to Choose ZL vs. MCZ

The Rubycon ZL data sheet bills this part as High Ripple/Low Impedance. The MCZ is the top of the line low ESR product. I have ZL on both system boards, and in power supplies.

Question: is there a criteria to use for choosing between ZL and MCZ?

iirc zl is a longer lasting line.i would lean to zl in a psu and mcz in a vrm.

[PCBONEZ]

Re: When to Choose ZL vs. MCZ

When you compare caps use EXACTLY the same can size and approximately the same uF. - ESR changes with can size not uF.

ZL is equivelent to KZE or HD
- Way below MBZ
- Suitable for VRM on P3 or below, in PSU's, or non-VRM caps on any board.
- Rubycon advertises it as for PSU's.

MCZ is equivelent to KZJ or HN
- Better than MBZ
- Suitable for VRM on anything, and anywhere else.

MCZ
8x20mm = .012 / 2350
10x20mm = .011 / 2770

ZL
8x20mm = .041 / 1250
10x20mm = .023 / 1820

.

[bgavin]

Re: When to Choose ZL vs. MCZ

KC8, thanks for the tip.

Bonez, good advice for ESR comparison. My question is not so much ESR related, as to which is most appropriate for a given use.

I understand the VRM to be around the processor socket, and typically several 3300uF caps. There also seems to be two to three much larger caps, 3300~4700uF separate. These are usually quite close to the ATX-12 connector.

These biggies (big can) are typically LXZ, HM, and ZL types. Those close to the cpu socket are typically HM, KZG, and various Fuhkyoo types such as Teapo SM, SC.

If the biggies are close to the ATX-12 connector, is it fair to assume they should be the longer life ZL when possible?

[PCBONEZ]

Re: When to Choose ZL vs. MCZ

No No No.
- - The uF all by itself doesn't mean that much on motherboards .
On motherboards caps used for filtering ripple (especially in VRM's) the #1 concern is ESR. You can fudge on capacitance a little bit (ideally in the direction of more) but NEVER NEVER go to a higher ESR cap. That would be bad jue jue.

Also: The terms "low ESR", "ultra low ESR", are for the most part useless.
The terms are not standardized at all. Every manufacturer has their own definitions for those terms and they don't correspond to each other. Company #1's "ultra low ESR" may be rated identically to Company 2's "low ESR".

- MoBo caps -

There is often a big input filter cap (or two) between the ATX plug and the VRM input.
May be by the ATX plug or by the VRMs.
There is usually a coil wound on a rod next to these.
This spot needs a good cap. (Go by the ESR not the uF.)
At least as good as those used in the outputs of PSU's but lower ESR is better.

-

VRM circuits usually have 'high' ('in') and 'low' ('out') caps.

The high (in) caps bridge the 12vdc input to the VRM to ground. [usually 16v caps.]
The lows (out) bridge CPU Vcore to ground.
[Usually 6.3v, occasionally 10v or even 4v.)

[[[ Highs can be on 5vdc vice 12vdc on older boards and may be 6.3v or 10v caps. ]]]

VRM 'low' does the most work and uses the lowest ESR caps on the board. There also may be more caps on the low side.

VRM 'high' are the next hardest worker and while they 'should' be as good'a'caps as the lows on some boards use 'less good' caps.

-

Other regulators that I can't think of the &*^$^* name for right now.
- Regulators close to some chip.. Point of ???? use??? regulators.
These usually only have one cap and no coil.
They SHOULD be at least HE/KY but they often aren't.

-

What I call 'field caps'.
These are the random caps scattered about the board.
They are low ESR but not very compared to a VRM.
Their job is basically to back-up the caps in the PSU outputs and keep the ripple out of the solder traces on the board.

-

The the I/O filter caps. - Near USB, Sound, PS2 jacks.
These are typically lower uF but higher voltage.
Reason is they aren't for ripple they are for EMI coming IN on attached cables.
The lower uF is better at filtering RF frequencies.
The high volts is to handle spikes when some ditz yanks out a cable suddenly with a device running or plugs the wrong gadget in.
These are just barely low ESR caps and sometimes are GP caps.

....

Below from my personal 'grade chart' with 8x20mm shown.
Only use as a guide to which data sheet to look in for replacements.
This was derived from looking at the 'factory' caps +/- 100 boards.

~~~~~
.009 / 2880 - [Used on high end boards to reduce caps count.]
HZ - GA
~~~~~
.012 / 2320-2350 - [Used to reduce caps count or on high-end boards.]
KZJ - GC - HN - MCZ
~~~~~
.016 / 1870 - [One up from standard grade used in VRM on P4 boards.]
NRSJ - FJ - FL
~~~~~
.018-.019 / 1870 ~~~~ [Typical minimum grade found in VRMs on P4 boards.]
MBZ - WG - GD - HM - NRSK
~~~~~
.021 / 1870
KZG <- I don't trust these. Too many fails reported and some on my own boards.
Found in VRM's on P4 boards.
~~~~~
.020-.025 / 1600-1700
ZLG <- Slated to replace the ZL series.
GE
~~~~~
.026-.033 / 1410-1560
ZLH, KZH, KZM, HV, NRSH, --- [These all are long life types.]
FM
~~~~~
.041 / 1250 - - - [Typical minimum grade found in VRMs on P3 boards.]
ZL, KZE, HD, WX, NRSG, GK
[Probably best min choice for PSU output caps if there are two caps per rail. If only one cap per rail go to ZLG or higher grade.]
[Min for the main input filter between ATX plug and VRM on the MoBo.]
~~~~~
.054 / 1250
ZT <---- High temp series. Good for hot running video cards or in hot PSUs.
~~~~~
.044-.069 / 1050-1220
[10mm spec range is narrower than 8mm in these series. Used 8mm here.]
[These are my choice for min in field caps.]
[Cheap or old mobos often use lower grades. Good boards use these or better.]
PA, FK, KY, HE, YXG, YXH
- - -
[These are field caps on old or cheap boards. May be seen in VRMs on old P2 boards. Used in modems, NICs. Used as I/O fither caps. Common in PSUs but not usually in the output.]
[There are other series that may fall into this catagory. - Got tired of looking.]
.065-.085 / 795-995
FC, PW, LXZ, PM(some), NRSX, NRSZ, JXA


~~~~~~~~~~~~
All of that said:
- these are not 'rules' it is only a guide to cross reference cap grades or to choose replacements if there is no data available on the original caps.
- by using more or less caps in parallel a manufacturer can get away with going up or down a grade or two. What I've said is what is generally found but there will always be exceptions.

[starfury1]

Re: When to Choose ZL vs. MCZ

You talking about 3 terminal type regulators (linear) Bonez? as in like 78XX 79XX
(not that I know even if they are found on MB these days...seems little switchers are being used more often in circuits (generally)...could be wrong?..just wondering)

Other regulators that I can't think of the &*^$^* name for right now.
- Regulators close to some chip.. Point of ???? use??? regulators.
These usually only have one cap and no coil.
They SHOULD be at least HE/KY but they often aren't.

to the question
Which ones ZL or MCZ and criteria (which is yes there is)
As pointed out above it does depend on the demands of the circuit.
(and condidtions cap will be exposed to)

yes... VRM near CPU coils and mosfets, usually a controller chip (like HIP6XXX) or other will be there somewhere too.


The Voltage Regulator (now not a Module) VRM

You could think of as high order "switch mode psu" in its self..designed to deliver very high currents in very short order with minimal voltage variations (tight voltage regulation, although there is a droop thats somewhat designed in)
(Were talking Amps in micro seconds type thing)

So does require good quality low ESR caps, anything not up to par may work but will fail a lot quicker due to the demands of the circuit.
(depending on cap type, demands and heat)

As bonez said, this is also important in regards to the input caps for VRM too (even thought you may tend to find a grade or so lower there)

old discontinued data sheet on a chip used for VRM ADP3188 give you an idea of how they work.

there are Intel VRM specifications docs out there too

So "generally" as KC8 said..ZL for PSU and MCZ for VRM

nice in depth reply Bonez

HTH
cheres

[bgavin]

Re: When to Choose ZL vs. MCZ

I don't understand the constant reference back to uF. I didn't state any intention of changing uF, or basing replacement on uF. I'm trying to understand if there is a time to use a ZL instead of MCZ on a board.

Evidently not. And I'm fine with that. That means I don't have to stock ZL, and can continue using MCZ.

I was looking at a hi-res photo of the Intel D955XCS board tonight. I noticed it is heavily populated with HD, KZG, SMG, and many of those are 85C types. In other words, borderline junk. It looks like any Intel board I pick up should be recapped for certain.

And, thanks for the long input above. I will digest, and incorporate it into my ever-growing spreadsheet library. I have all the data sheets for all the caps, and am mulling over how to read them. I figure if I stick with MCZ, I can't go wrong.

[starfury1]

Re: When to Choose ZL vs. MCZ

OK that puts it in a slightly different light
well suppose this really is a question for those that recap on a day to day basis as to whats ideal to stock

Me I think defiantly MCZ is a must since most issues will probably be VRM related, weather you want to use them in possibly more general area's I suppose comes down to the price you get them for in quantity.

I think generally the use would be OK
but there are times when a caps better qualities has been known to cause issues...
so I'll leave that open to those that do it on a day to day basis to answer on that one, they would be best to answer.
(some might consider this as wasting a good cap, when a lesser quality one will do or for that fact might be better suited in more general position)

I do agree thought only having to stock a few choice caps rather then variations of brand types and specs has to be an advantage to you in purchasing.

I'll let Bonez answer for himself
but think he was just trying to drive the point home that ESR is the critical thing not the capacitance and that construction of cap will determine the ESR more so then the actual value of capacitance.

If you are doing PSU's as well then you might be advised to stock the ZL...its a horses for courses thing.

Using MCZ in a PSU is " probably not" a good choice

Hope this is of some help anyway

Cheers

[PCBONEZ]

Re: When to Choose ZL vs. MCZ

Yes Starfury that was the point of all that.

Look at the ESR of the original cap first when choosing replacements.

bgavin:
MCZ are fine to replace about anything you'd normally run across.
The range of sizes available is somewhat limited.
No 6.3v 1000uF and highest 6.3v is 3300uF. Highest 16v is only 1800uF.
They probably cost much more than some other series.
Seems like a waste to use them on P3 boards or for general 'field caps' on anything.
Suppose it depends if you need dozens or thousands AND what you usually work on.
I have a Tyan dual P3 Tualatin server board that's populated entirely with ZL (as original) and she run ~ so fine!

HD and KZG are both 105C caps.
I don't trust KZG anymore but some people haven't had problems with them.
SMG are 85C GP caps and really shouldn't be on a MoBo if you ask me.

Actually Starfury the proper name for what used to be a VRM is now VRD.
[VR "Down" - According to Intel.]
I think that sounds rather stupid so I continue to use VRM to specify the CPU's VR and just VR if it's not for the CPU.

I was talking about a standard Buck/Boost MOSFET arrangement which is what I usually see.

.

[starfury1]

Re: When to Choose ZL vs. MCZ

yeah I knew it got changed to something but couldn't remember what the more correct term was now.
True too the original abbreviation of the names do tend to stick and sometimes the original meaning gets lost.

OK.. thanks for clearing that up re the "VR" (not linear regs)
(In my post that should have been "Are you talking...", it was a question not a statement...I just noticed that on a reread, it could be taken as a statement).

cheers

[bgavin]

Re: When to Choose ZL vs. MCZ

Thanks to both. My concern is two-fold, both for stocking levels and the very best cap for a given purpose.

When I saw the ZL on the motherboard, I got to thinking that an MCZ might be wrong, because ZL is a High Ripple type. From previous conversation, I will be leaving MBZ and ZL untouched when I do a recap.

Let's change to power supplies: I find Teapo SEK and LXK in my favorite supply, and want to replace them. These are 85/105C general purpose caps rated at 1000 hours. I assume requirements for PSU are somewhat different than motheboards. What are the optimal series for PSU?

[PCBONEZ]

Re: When to Choose ZL vs. MCZ

Nah,
-
As long as the uF and volts is right MCZ should work anywhere on anything.
[If it fits on the PCB.]

It's just other caps may be more cost effective so I wanted to give complete information. - That's all.

Teapo are generally fine in PSUs but I wouldn't trust them as the final output filter caps. - There are a lot of areas inside a PSU that don't need low ESR caps.

For me the output filters are just too easy to change to leave anything less then ZL/KZE there. If I get stuck with something like 3300-4700uF in a 10mm can and there is no way to use a 12.5mm cap [that I know of only Fuhjyyu and OST make those damned things] I'll use MBZ 3300uF 10mm. [Mostly because I have MBZ's. MCZ would be even better.] The much lower ESR and higher ripple capacity compensates for the reduction in uF and the advertized uF in the original Fuhjyyu and OST is probably bogus anyway.

Now the temp thing.
Using 85C in a PSU in small caps on the PCB sounds like a poor engineering practice to me. - But: It's common for those two huge caps on the AC side to be 85C and those don't usually have heat problems. They are big enough to dissipate the heat load.

.

[bgavin]

Re: When to Choose ZL vs. MCZ

Rubycon PX comes in a 10mm can for 3300uF and 5500uF at 10v.
I have not found a bulk source for PX yet. Wai Fong in Hong Kong does not carry them. A pity, as I get banged $20 USD for shipping no matter how many I order so I like to buy them all in one place.

I was very surprised at the D955XCS Intel board having a large number of 85C SMG in the field. This is a delightful looking board, and is available in BTX format. I have a new D945GCZ board in stock which has a slew of 85C field caps (VR, VP). The remainder are HM, MHZ, KZE, ZL.

[PCBONEZ]

Re: When to Choose ZL vs. MCZ

I don't know where your reading.

My datasheet says PX only go to 3300uF in 6.3 and 10v and even then the ripple they handle is 1100 mA or less. The 6.3v MBZ 3300uF handles 2800 mA.
-
PX would be a good cap for general use in PSU's but I wouldn't use them in output filters.

~~
Thanks for tryin' though!

.

[PCBONEZ]

Re: When to Choose ZL vs. MCZ

I was very surprised at the D955XCS Intel board having a large number of 85C SMG in the field. This is a delightful looking board, and is available in BTX format. I have a new D945GCZ board in stock which has a slew of 85C field caps (VR, VP). The remainder are HM, MHZ, KZE, ZL.

Intel using 85C caps surprises me too.

Are these special purpose boards intended to be used in network appliances or something? - That might explain it.

.

[Kaine]

Re: When to Choose ZL vs. MCZ

So if i use a bunch of MBZs to replace some stressed out KZGs (undercooled VRM, they are too hot to touch, running 24/7) I'm going in the right direction? Would it be worth sourcing some MCZs, or is the difference not worth it?

[PCBONEZ]

Re: When to Choose ZL vs. MCZ

So if i use a bunch of MBZs to replace some stressed out KZGs (undercooled VRM, they are too hot to touch, running 24/7) I'm going in the right direction?

Yes

Would it be worth sourcing some MCZs, or is the difference not worth it?

MBZ are already better than good (not failed) KZG and will do fine there.
-
If you have MBZ already the difference isn't worth sourcing others.
If you need to order then get the best deal on any of these:
~~~~~
HZ - GA
~~~~~
MCZ - KZJ - GC - HN
~~~~~
NRSJ - FJ - FL
~~~~~
MBZ - WG - GD - HM - NRSK
~~~~~

.

[Kaine]

Re: When to Choose ZL vs. MCZ

So if i use a bunch of MBZs to replace some stressed out KZGs (undercooled VRM, they are too hot to touch, running 24/7) I'm going in the right direction? Would it be worth sourcing some MCZs, or is the difference not worth it?

Forgot to say the MBZs I have are slightly hugher capacitance than the KZGs i'll be replacing 1500uF 6.3v and 1000uF 16v KZGs with 2200uF and 1800uF MBZs. Stupid forum software edit time limit.

Speaking of which;



See the unpopulated spots? Any suggestions on what I should put in them? For reference it is an A8N-SLI Premium (socket 939). The heatpipes will be going pretty soon (having a waterblock made for the VRMs) and I figure since I'm going to have a few spare MBZs I might as well populate them.

[PCBONEZ]

Re: When to Choose ZL vs. MCZ

You are replacing what with what?
I would get caps closer to the originals especially if you are adding more caps.

A little tid-bit is that if you reduce the ESR you can get away with slightly LESS uF.
[That's why those poly caps can be used with such low uF.]

Also per Intel docs raising uF has rapidly diminishing returns.
One step up might help -a little- but more than about one step up in uF gains nothing.

Modders and over-clocker have gotten the idea that raising the uF helps.
What they don't realize is that because they tend to buy the better grades of caps to do this with they lowered the ESR and THAT's what helped them out. Not the higher uF.

Replacing KZG with any of those above reduces the ESR.
Adding caps in parallel also reduces ESR (and raises the uF).

.

Before you go replacing caps that weren't there in the first place trace the circuit with a meter. If the pad is not in parallel with the other caps then leave it alone.

.

Between the VRM caps is a really DUMB location for a heat pipe!!!
No wonder you boiled your KZG's.

.

[Kaine]

Re: When to Choose ZL vs. MCZ

1000uF 16V KZG will be replaced with 1800uF 16V MBZ
1500uF 6.3V KZG will be replaced with 2200uF 6.3V MBZ

The only reason I'm going up a step in capacitance is because that's what I've got laying around reclaimed them from a working gigabyte board that wasn't needed any more. Increasing total capacitance isn't what I was going for, I'd actually be happier if they were the same size or smaller but I'm working with what I have.

I agree that it's a stupid place for a heatpipe cooler. Can't believe they thought this design would be superior to cooling the chipset and VRMs separately. The whole idea hinges on the CPU HSF blowing air across that pissy little aluminium sink. The KZGs are still functioning but I can't imagine them being very healthy at this stage.

Thanks for the advice on the unpopulated positions, I'll hold off on them at least until I have an idea of what they do and I've got the board stable with the new filter caps.