Hi,
I try using an sn74lvc1g3157 analog switch by TI (
datasheet), but burnt two already.
The package is SC70 (all I could find without paying way to much for shipping). So first thing I did was deadbug soldering to a pinheader :
The photo was just taken to check marking, I cleaned the IC before using it.
First thing : the datasheet says I should find a dot, but I did not. There is a marking saying
|C5J. I could verify that this is the chip I ordered, and guessed that vertical bar is on the side of pin 1 - so if I made no mistakes, pins on the from left to right pin of the pin header are 1..6, but am not 100% sure.
Second thing, I plugged this on a breadboard, burnt it (it started to heat then pin 5 and 6 reads 6 ohm). soldered another chip and redid everything from sratch, called an electronic professor on youtube to thow him what I did, it took time, said that should work, so I plugged power in and... the IC heated so much that one of the wire disoldered. After that I again hade continuity betzeen pin 5 and 6 (i checked before that there were no shortcuts of course)
Here is what I did :
Red track is 5V from USB (from a laptop).
On the right part an LM317 is used to provide 1.86V on the yellow track.
The bottom potentiometer is use to ensure at least 4mA are drown on the yellow track so the LM317 can regulate (I checked that it does)
Then there is the analog switch with the pinout I think it has. B1 and B2 are tied to 0 and 1.85V so I expect to read either on A
Finally, S is tied to 0 and I should be able to plug it to 1.86V to change the voltage on A... but the IC burns before.
Any idea what I am doing wrong before I solder 6 0.65mm pitched wires again ^^ ?
Thx,
John.