TS3L501E: 16-Bit to 8-Bit multiplexer is not passing Blue light test

Part Number: TS3L501E

I am attempting to us the TS3L501E to switch between two Ethernet ports.  My schematic is shown below. 

If I use an ohm meter to test the switching function, it seems to work fine.  A few ohms when it is switched on and a few megaohms when off.  The resistance between the pins, on the same connector is around 2M.  However, when I tested with a cable tester it shows that some of the signals are open and that some are crossed.  Is it possible the chip was injured by the hot air soldering. or is this crosstalk or something else?  I have routed the airs together with 7mil spacing, and ave put  at least 50mils between pairs.

Jeff Penman

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1 Reply

  • Jeff,

    That is good news that the device is showing low resistance and high resistance as appropriate.

    I checked your pin routing from the device to the connectors and didn't see anything out of place.

    I'm not familiar with a cable tester. Would you please describe what the cable tester is doing. What does it mean to the tester that a signal is crossed or open? If the cable tester is seeing an open signal is it possible it that the switch is off (Hi-Z)?

    A good technique to find out if the switch is causing an issue or not will be removing the part from the board and shorting the pads to see if you have the same issue.

    Thank you,
    Adam