Hey all. This is interesting; I ordered a chip from National Semiconductor. It's a LM4921ITL. It's about 2mm wide, 1.5mm long, and 0.5mm tall. It is a 16bit stereo I2C DAC with 32ohm headphone amplifiers, and digital volume control.
I ordered it because I like the simplicity of the I2C bus architecture and I would be interested in interfacing with audio.
I figured it was a standerd SOIC when I ordered it and didn't look at the datasheet. When it came I almost couldn't find the chips in the package (I ordered two.) I shook the tiny wee little flake of a package out of the static bag and admired it on the table. At first I thought it was a bit of plastic garbage that got into the package, but there were no chips. I looked closer at the little flake and found that it was a blister package with two chips in it.
I had to use tweezers and a razor blade to open it, even that was hard. I got one chip into my hand and glared at it, trying to count the almost microscopic pins. There are 20 of them, little bumps of metal on the bottom side of the chip. I could probably wedge the chip between two teeth to hide it. It is easily confused for a tiny shred of garbage plastic.
The question is, does anybody know anything about getting boards for these chips??? I know there are boards, but I'm not sure where to get them??
This pic shows the chip, between an 8088 processor, and a DIMM.
As you can see, the chip is barely twice the width of a "pin" on the 8088...
I ordered it because I like the simplicity of the I2C bus architecture and I would be interested in interfacing with audio.
I figured it was a standerd SOIC when I ordered it and didn't look at the datasheet. When it came I almost couldn't find the chips in the package (I ordered two.) I shook the tiny wee little flake of a package out of the static bag and admired it on the table. At first I thought it was a bit of plastic garbage that got into the package, but there were no chips. I looked closer at the little flake and found that it was a blister package with two chips in it.
I had to use tweezers and a razor blade to open it, even that was hard. I got one chip into my hand and glared at it, trying to count the almost microscopic pins. There are 20 of them, little bumps of metal on the bottom side of the chip. I could probably wedge the chip between two teeth to hide it. It is easily confused for a tiny shred of garbage plastic.
The question is, does anybody know anything about getting boards for these chips??? I know there are boards, but I'm not sure where to get them??
This pic shows the chip, between an 8088 processor, and a DIMM.
As you can see, the chip is barely twice the width of a "pin" on the 8088...
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its seems to be a Ball Grade Array ( BGA that is ) with a pitch off 0.5mm, sort off inpossible to place by hand, only with Pick and place machines these devices can be placed onto a PCB.
for the information, BGA's go *** tiny as a pitch off 0.3mm
thats were the fun begin
To help you a little bit, i ones placed a BGA on a board simply by soldering the pads on te board, placing the chip, then add som glue to be sure the chip didnt move anymore, then burned the thing with a hairdryer from the bottemside from the pcb, this only worked for me 1 time out of 3, but that one time did it for me, good luck, you'l be needing it
for the information, BGA's go *** tiny as a pitch off 0.3mm
thats were the fun begin
To help you a little bit, i ones placed a BGA on a board simply by soldering the pads on te board, placing the chip, then add som glue to be sure the chip didnt move anymore, then burned the thing with a hairdryer from the bottemside from the pcb, this only worked for me 1 time out of 3, but that one time did it for me, good luck, you'l be needing it
Well, this was never supposed to happen, but I actually AM going to be soldering that chip in P2P. It's going onto a piece of veroboard so that I can easily connect it into a circuit. I'm actually going to put two of these chips on one board so that I can run them simultaneously. Or, if I want, I can break the board into two independant chunks and use each one in a different project.
Can anyone tell me exactly how insane I am????
. It's going onto a piece of veroboard so that I can easily connect it into a circuit. I'm actually going to put two of these chips on one board so that I can run them simultaneously. Or, if I want, I can break the board into two independant chunks and use each one in a different project.Can anyone tell me exactly how insane I am????
Yeah, it leads me to believe that the human body can still do things that only machines are supposed to be able to do. I mean yeah, a computerized pick and place machine could have installed that chip in seconds. The point is that I could still do it by hand with a standard size soldering iron, ordinary wires, and without any optical magnification either, just my bare eyes and also bare hands.
I'll have to see if anyone makes a chip with smaller pins on it so I can test my abilities.
I'll have to see if anyone makes a chip with smaller pins on it so I can test my abilities.
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