Hi Ti experts,
We are using ISO I2C ISO1540 to connect MCU and many devices as below:
We found that when ISO1540 receives signals from MCU, there will be a platform at the rise edge as below, which will cause the communication rate down to 300kHz.
Could you please help figure out the reason why there is a platform during signal rises.
Hello Gary,
Thank you using ISO1540. This behavior is expected from bidirectional digital isolators. Side 1 will have higher VOL in order to prevent a latch up condition on the isolated channels (See [FAQ] Why is the logic LOW level output voltage, VOL1, up to 0.8V on Side1).
The datasheet defines this spec as t_loop shown below:
Best,
Andrew
