Building a ddr booster

[stealth17]

is there anyone that would have the knowledge to help me build a ddr booster?

what im looking for is Xtreme Clean power, and something that can adjust and display the voltage in thousandths.

i dont need vtt tracking or any of that stuff just a something basic to supply stable and clean power to my ram. i can solder it to the boards vdimm mosfet if possible to eliminate needing a pcd card in a memory slot.

if this all works nicely im considering making one for the vcore

i know a little about circuitry, ive been reading up on power stabilization and EMI. but i still think im ganna need a bit of help

thanks!

[Micutzu]

You should try this out, it works just like the booster, but the voltage drops in load at least 10 times less, and the power delivered is also much cleaner, especially if the 1000uF capacitors are high quality.



The "remote sense" and the "output" wires need to be connected together, but only at the soldering point on the motherboard, this way you'll have the best voltage stability. Watch out, the BD135 and especially the BD911 transistor gets very hot, and will need heatspreaders.
The output voltage will be adjustable from 0 to ~4.2V, with an output current that is more than enough for 2GB of TCCD or BH-5/UTT in any conditions. The maximum voltage depends on the stability of the +5V line, and is about 0.8V lower; if you have an adjustable PSU and you'll get the +5V rail up to let's say 5.5V, then the maximum voltage will be 5.5-0.8=4.7V.
It doesn't display the voltage though, you'll need a multimeter for that.

[persivore]

This is the circuit that I used to provide regulation for the DDR booster. It can be simplified a lot by removing some of the components, but it might make the Vdimm supply slightly more unstable. It will provide a variable Vdimm supply of between 2.5 to 4.3v iirc, with a fluctuation of 0.01v with good grounding, or possibly better. You can use any general purpose MOSFET, as long as it is able to withstand the high currents RAM needs (a rating of about 15A should be suitable)

[stealth17]

You should try this out, it works just like the booster, but the voltage drops in load at least 10 times less, and the power delivered is also much cleaner, especially if the 1000uF capacitors are high quality.



The "remote sense" and the "output" wires need to be connected together, but only at the soldering point on the motherboard, this way you'll have the best voltage stability. Watch out, the BD135 and especially the BD911 transistor gets very hot, and will need heatspreaders.
The output voltage will be adjustable from 0 to ~4.2V, with an output current that is more than enough for 2GB of TCCD or BH-5/UTT in any conditions. The maximum voltage depends on the stability of the +5V line, and is about 0.8V lower; if you have an adjustable PSU and you'll get the +5V rail up to let's say 5.5V, then the maximum voltage will be 5.5-0.8=4.7V.
It doesn't display the voltage though, you'll need a multimeter for that.

pic doesnt work

[Micutzu]

There you go.

[stealth17]

There you go.

looks nice. should i add any inductors to help clean the power more?

i cant read all of the lettering....what does C5 say? is that a diode?

thanks

[Micutzu]

I've also used a inductor but there was a load voltage drop of about 0.02V on it, so i decided to give up on it. C5 is a 22uF capacitor, connnected in paralel with D1 wich is a 1N4148 diode.

[stealth17]

I've also used a inductor but there was a load voltage drop of about 0.02V on it, so i decided to give up on it. C5 is a 22uF capacitor, connnected in paralel with D1 wich is a 1N4148 diode.

this is a linear design thus the heat correct?

[Micutzu]

Yes, that's a linear voltage regulator.

[stealth17]

anyone have a scematic for a switching design?

[persivore]

anyone have a scematic for a switching design?

If you can wait until next week, I'll have a go at drawing up a switched mode design, but its likely to be a lot more complicated than a linear supply (at a rough estimate I think I can probably do it with 4 opamps and a few resistors and capacitors and a MOSFET/transistor, unless you can find a dedicated chip to do it all for you)
IMO, a switching supply will be a bit overkill for the purpose. A simple linear regulator should provide similar performance, but with more heat output.

[Micutzu]

I think a linear regulator is more appropriate here, since it generally offers cleaner voltage output with no switching noise.

[stealth17]

linear supply has cleaner power? hmmm.....switching is much more efficient though. i need something that can put out about 40 amps without breakin my balls. i just want good clean stable power...thanks for the help guys!

[Micutzu]

I do agree that switching is more efficient, but in this case it really isn't required. Plus, the schematic i gave you puts out 15A, and considering that a standard 512MB PC3200 stick needs ~1.5A in full load, you can guess you have a nice margin there for even 2GB of memory.

[stealth17]

I do agree that switching is more efficient, but in this case it really isn't required. Plus, the schematic i gave you puts out 15A, and considering that a standard 512MB PC3200 stick needs ~1.5A in full load, you can guess you have a nice margin there for even 2GB of memory.

opps i told oyu the wrong amperage.

http://www.xtremesystems.org/forums/...701#post633701

so i need about 12amp atm. will linear be enough to put out 15amps without getting hot? id like a switching so it doesnt put out as much heat if possible. is there any way to add some high uf caps (i have a bunch of 1200uf caps from an old p2 mobo i can use) to help stabilize the voltage more? i basically want a current that good and stable like a vcore current and use that for my vdimm

[Micutzu]

Well, if it's done right (thick wires, good soldering, quality parts) that schematic will have a voltage drop of about 2mV/A, that's more than 10 times less than the OCZ Booster and comparable with a good onboard RAM voltage supply.

[stealth17]

If you can wait until next week, I'll have a go at drawing up a switched mode design, but its likely to be a lot more complicated than a linear supply (at a rough estimate I think I can probably do it with 4 opamps and a few resistors and capacitors and a MOSFET/transistor, unless you can find a dedicated chip to do it all for you)
IMO, a switching supply will be a bit overkill for the purpose. A simple linear regulator should provide similar performance, but with more heat output.

ygpm

[SoddemFX]

I dont like linear, maybe just me Switching with good filtering would be the way to go in my opinion...

What about using the PWM from a PIC to implement a full single phase PWM?

Feed a N-channel enhancement mode MOSFET as the upper FET with an invertor feeding the lower N ench FET. Feedback referenced against a LM336, output fed through a potential divider to scale it the the ref diode range before going into a ADC channel to compentsate PWM duty cycle to desired voltage. Ouput to basic LC...

You could also have LCD voltage display (or even temp. with a LM335?), RS232 communication, whatever. The whole thing in one package with a minimal amount of extra components...

Ive got a shed load of LM336's, low ESR caps, ceramics, inductors, N-channel ench MOSFETS rated from 10A - 48A. I've been planning to build one of these for a while, im planning on using a 16F877, but you have 2 PWM and 8 ADC -why not do Vtt too?

Only problem i can think of is the ADC being 10-bit, resoloution of 4 mV. Nasty thoughts of it going unstable...

Maybe just use one of the buck regulator IC's instead and add extra control?

How about drawing up plans for an XS homebrew DDR booster?

Tom

[stealth17]

I dont like linear, maybe just me Switching with good filtering would be the way to go in my opinion...

What about using the PWM from a PIC to implement a full single phase PWM?

Feed a N-channel enhancement mode MOSFET as the upper FET with an invertor feeding the lower N ench FET. Feedback referenced against a LM336, output fed through a potential divider to scale it the the ref diode range before going into a ADC channel to compentsate PWM duty cycle to desired voltage. Ouput to basic LC...

You could also have LCD voltage display (or even temp. with a LM335?), RS232 communication, whatever. The whole thing in one package with a minimal amount of extra components...

Ive got a shed load of LM336's, low ESR caps, ceramics, inductors, N-channel ench MOSFETS rated from 10A - 48A. I've been planning to build one of these for a while, im planning on using a 16F877, but you have 2 PWM and 8 ADC -why not do Vtt too?

Only problem i can think of is the ADC being 10-bit, resoloution of 4 mV. Nasty thoughts of it going unstable...

Maybe just use one of the buck regulator IC's instead and add extra control?

How about drawing up plans for an XS homebrew DDR booster?

Tom

that sounds like what Im looking for. since vtt seems to be a problem even on the dfi nf4 boards, yes, lets implement vtt also.

Im not that good at drawing schematics (obviously lol), so I cant really help there

The vtt circuit will need 3 amps, Id say call it 5 to be safe and furture proof.

-Jordan

[goatman]

I dont like linear, maybe just me Switching with good filtering would be the way to go in my opinion...

What about using the PWM from a PIC to implement a full single phase PWM?

Feed a N-channel enhancement mode MOSFET as the upper FET with an invertor feeding the lower N ench FET. Feedback referenced against a LM336, output fed through a potential divider to scale it the the ref diode range before going into a ADC channel to compentsate PWM duty cycle to desired voltage. Ouput to basic LC...

You could also have LCD voltage display (or even temp. with a LM335?), RS232 communication, whatever. The whole thing in one package with a minimal amount of extra components...

Ive got a shed load of LM336's, low ESR caps, ceramics, inductors, N-channel ench MOSFETS rated from 10A - 48A. I've been planning to build one of these for a while, im planning on using a 16F877, but you have 2 PWM and 8 ADC -why not do Vtt too?

Only problem i can think of is the ADC being 10-bit, resoloution of 4 mV. Nasty thoughts of it going unstable...

Maybe just use one of the buck regulator IC's instead and add extra control?

How about drawing up plans for an XS homebrew DDR booster?

Tom

what about the electrical noize?
the ram and the rest of teh system will pick all that up!!
u'd need to encase the power supply

[SoddemFX]

goatman - What about electrical noise? I dont understand what you mean...

As long as you have good isolation on the PCB i dont think it would be an issue, you'll have the PIC main oscillator, RS232 and LED strobing but dont see why with good filtering and PCB design you couldnt avoid any probelms.

I've got to admit that ive never built anything like this before with such accurate limits on voltage output, closest ive done is motor and heater control. My analogue is a bit ropey so any help would be much appreciated

Stealth17 - The lowest FETs i have are 10A, so it would be about 15A Vtt, not like you need that much, just that i dont want to buy unnecessary stuff. Also TO220 is a nice size

Tom

[lyquochaokiet]

i search the web and finnally i found this , i seeen micutzu pic , but i dont know what is sense line in his pic ??

i wonder which pin of ddr module we feed the voltage ?

sorry , english is not my main language.

[stealth17]

i search the web and finnally i found this , i seeen micutzu pic , but i dont know what is sense line in his pic ??

i wonder which pin of ddr module we feed the voltage ?

sorry , english is not my main language.

dont use that micutzu pic....He made a new one that is better. Ill post it tonight....

[lyquochaokiet]

i'm waitting for urs pic ,

but when we build that ddr booster module , we need a special pcb for that ? i was sacrifried a 256 ddr module for that ...... what did you use for booster pcb ?

[stealth17]

T = STP55NF03L
IC = TL431
C1, C3 = 3300uF/6.3V low-ESR
C2 = 100-470uF/16V low-ESR
R1 = 390ohm
R2 = 1.5Kohm
P = 1Kohm multiturn

Try to get high-quality parts, so the voltage stays as clean and stable as
possible. The mosfet (T) gets very hot, so you need to mount it on a
heatspreader; watch the isolation, it's metallic part of the case is
connected to the D pin and therefore directly to the PSU's +5V line. The
output wire should be as thick as possible, because that's the only thing
it can cause voltage drop. If well built, this circuit should provide zero
voltage drop and extremely clean power.

To supply the voltage you find out where to solder the output of the booster onto the motherboard. You dont use a DIMM slot....

Make your own PCB, doesnt need to be anything special size or shape wise.