Hello,
Usually, PECL output termination is 50ohms to Vcc-2V.
However, looking at the figure38 on page 14 of SN65LVDT101 datasheet, it is 50ohms to GND, not 3.3-2.0V.
In this case, if Vcc=3.3V, Ioh/Iol can be calculated as around 45mA/32mA.
Can SN65LVDT101 really tolerate such high output current?
I think, in case of terminating to GND, usually 130-150ohms are used to avoid too much high output current, though.
Best regards,
K.Hirano