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Replacing a TSSOP part with pass thru lines
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Replacing a TSSOP part with pass thru lines

by eagleski on Tue Sep 26, 2017 7:24 pm

Folks,
I'm trying to find an easy way to lift a TSSOP part off of a production board and replace it with a part that would have a straight pass thru on 5 of the data lines. Unfortunately we don't want to use this TSSOP voltage leveler and need it to just pass thru 3.3V signals directly.

Is anyone aware of a straight pass thru for TSSOP parts that would simplify the rework? Yes, we should have caught this in design, but with 60 boards out there, we can't just start over.
Thanks,
Eric

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Re: Replacing a TSSOP part with pass thru lines

by adafruit_support_mike on Tue Sep 26, 2017 11:09 pm

I don't know of any 0-ohm resistor networks in TSSOP packages, but you might be able to find a buffer with the same pinout.

Would it be possible to leave the existing chip and drop its supply voltage to 3.3v?

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Re: Replacing a TSSOP part with pass thru lines

by eagleski on Thu Sep 28, 2017 10:37 am

I tried keeping 3.3v on each side of the voltage leveler and received unpredictable results...as it expects an increase in V on the right side of the chip. I tested with a bunch of rework to circumvent the TXB0108PW and it worked well, so the easiest thing would be to heat gun this off the board and pop in a same footprint pass thru chip...

Have you heard of a TSSOP isolated resistor array?

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Re: Replacing a TSSOP part with pass thru lines

by adafruit_support_mike on Fri Sep 29, 2017 1:09 am

I've never looked for one, actually, but a quick check at Mouser and Digikey shows that they do exist.. the ones listed as TSSOP are made by Vishay and are a bit pricey:

https://www.digikey.com/products/en/res ... ageSize=25

But check out the 'SOL' and 'SOM' packages too. Bourns makes some of those, the dimensions look similar, and manufacturers use an alphabet-soup of private names for the same basic thing.

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