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LT3960 wrong translatation

Category: Hardware
Product Number: LT3960

HI,

I'm using the Eval-Board EVAL-LT3960, one setup as Master, the other as slave, both using the internal LDO.

On the master I'm feeding in a slow I²C instruction to read an TMP100. As cable I'm using ~25m twisted pair wires, GND connected.

1. measuring SCL on both sides looks fine and in sync.

2. measuring SDA seem weird. The differential signals seems to be translated correct back to I²C signal on the slave, however completely different to the I²C signal feed in -> see attached plot
  it can clearly be seen, that I²C in and I²C out signal differs significant hence no communication possible

Any idea what's going on?