Hi,
As TXB0108 is auto bidirectional voltage translator, does it work like one IO is flowing A(input) to B(output) and another IO is flowing B(input) to A(output) at the same time ?
OR ALL the IOs have to be in same directional flow('B to A' OR 'A to B') at the same time ?
Thanks in advance.
bidirectional feature scope
Hello Vishnu,
The device operation is shown in the datasheet:
I know there's a lot going on, so I tried to simplify it a bit by highlighting two paths.
The yellow path is for normal (DC) operation. That inverter is always outputting on both sides of the device, but it has a series 4kohm resistor that limits the output current significantly.
The red path is the transient path that only activates when a level change is detected on the opposite side of the device. The two boxes labelled "One Shot" cause a very short pulse to trigger the inverters when the opposite input is switched from LOW to HIGH or HIGH to LOW.
It's important to note that the one-shot inverters do _not_ have series 4kohm resistors, and thus have much higher drive strength. This is what provides the TXB0108 with fast edges.
Here's a drawing (also from the datasheet) that shows a single IO cell:
I think it's a little clearer - here you can see that the one shots are actually built in two parts and either help the rising or the falling edge, depending on the detected change.
