Reply 8880 of 29603, by feipoa
- Rank
- l33t++
I've attached a few different vantage points and placed the QFP SXL2-66 next to it for comparison.
Yes, this is essentially what I was working on. Someone online pointed out this particular item for sale, so I figured I'd grab it for comparison. I had hoped that it contained a voltage regulator, but it didn't. Someone on CPU world claims he has one with a VRM and I have been bugging him for a photo, but no photo has turned up as of yet. Hopefully, if life improves for me, I'll pickup the PCB design efforts for this late in the fall. Obviously, I'd want to include a VRM. I don't like it when the stack gets so tall like this. I also don't like all the added circuitry.
The PGA132 to PGA168 interposer contains a quad 2-input NAND gate (74VHC00) and a 7-bit counter (74HC4024D). The counter appears to be counting clocks and resets when pin 2 is triggered high. I wish there was documentation on what functions these serve. The Gainberry VRM interposer contains 3 logic chips: a dual comparitor (LM393M), a band-gap voltage reference (LM385), and a mystery IC with markings BHΔ w542. Of course, it also a voltage regulator module, LT1528CT. My second Gainberry VRM has a defective LT1528CT, so I am having to order a replacement. I will run the SXL2-66 at 3.6V on the replacement Gainberry because it is modded already with a trimmer.
Perhaps someone has some idea as to what value these IC's provide to these interposers? The PGA 132 version of the SXL2-50 works just fine without them, so...
On my design, I would want to centre the PGA132 to the PGA168 for symmetry.
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