Recent content by fiedel

I thought the wiggly lines are such signals like data and address, but not pull-ups...

When pulling up DDR2 signals with resistors, how to decide the power consumption of them, or I can just use 0402 resistors? And for the tracks connecting the resistors to the VTT (or the resistors to the signals), is there a impedance matching problem? Should them be of the same length?

Well, I see the pinout description on their website, for cable assemblies. Molex provides several selection for cable length. Impedance control is another problem for me. I can only find such information for edge connectors. It must have been defined in PCI Express External Cabling...

I want to interface two processing boards with PCI express x8 and connect them with cables. I find 68-pin off-board connectors for x8 connection (by molex) where as there're 98 pins for edge connectors. How do I match these 98 to 68? Are there some documents talking about this? I read PCI...

This is very attractive idea. I'll definitely try it. Thank you Mike!

Thank you negitron for your kind offer. I will try the methods. I really hope I don't have to bother you.:smile:

Wow, I have a 2x magnifier...

Thank you for such detailed instruction! I'd go and get some fine-things and give a try. I can see the pads extend out very very slightly, and that's how I can allign the chip. Soldering the pins with iron will be very difficult, I guess so, because the chip is so sensitive to a non-vertical...

Thank you negitron. Swipe method is great for QFP chips, but I'm not sure if it works for this QFN chip because it dones't have long pads that can be reached by iron tips.

The chip is TI CC2400 - is it this one? I'm soldering with WHA900 hot air gun from Weller. The nozzle is NQ40 (26.0mm x 26.0mm). It's much bigger than the chip, but I only have this one at hand... The solder is Kester 275 which is lead free with melting point 422 ~ 428°F. I distributed solder...

Thank you berkeman! Unfortunately I'm in New York and I haven't heard of any local assembly houses around. I quoted from some companies from their web sites, approx. $20 each for less than 100 pieces. Is it that expensive? The datasheet says the safe temperature for reflow soldering is less...

Hi there, I have a tiny 48-QFN chip that I have to solder manually. The pin width of the chip is .28mm and the clearance of the pins is .22mm. The pins are totally under the chip and from side I can only see little metal indicating the positions of the pins, which makes it impossible to...