THVD1406: Can this transceiver support 100kbps speed in auto direction mode?

Hi Shaury, 

The short answer is that the auto-direction feature does not have a minimum data rate. It is more important to know how long the system expects to be idle before direction change is allowed. This minimum wait-time is what the tdevice-auto-dir timer constrains. 

After a low-to-high transition on the D pin and the 8µs timer has expired, the bus pins A and B will be high impedance, but this does not mean data can no longer be transferred. The fail-safe biasing feature of these devices interprets an open or undriven bus as a logic high. This means a logic high can be sent at any data rate using this device. What will change if this high level is driven long enough is that the device receiver will become active. Because the bus is still in a logic high state, the R pin will not change states (provided it has a pull-up resistor to bias it while it is high-z). 

Let me know if this is clear and if you have any more questions.

Regards,
Eric Schott