ADuM1440Recommended for New Designs
The ADuM1440/ADuM1441/ADuM1442/ADuM1445/ADuM1446/ADuM1447 are micropower, 4-channel digital isolators based on the Analog Devices, Inc., iCoupler® technology...
Datasheet ADuM1440 on Analog.com
ADUM1252Recommended for New Designs
The ADuM1252 offers two bidirectional, open-drain
channels for applications, such as I2C, that require data
to be transmitted in both directions on the...
Datasheet ADUM1252 on Analog.com
I2C always requires at least a bidirectional SDA line so a peripheral can send back an ACK bit and data to the MCU. The SCL line may or may not need to be bidirectional; it depends on what peripherals are being used and if they need to do something like clock stretching.
The ADuM1440 has 4 unidirectional channels, so it will not work for I2C bus isolation. Communication in the direction of the wireless base board is not possible in the schematics above, and the push/pull outputs of the ADuM1440 may even be causing communication issues on the MCU side.
There is an ultra-low power I2C isolator in the ADI portfolio. I recommend considering the ADuM1252.
I2C always requires at least a bidirectional SDA line so a peripheral can send back an ACK bit and data to the MCU. The SCL line may or may not need to be bidirectional; it depends on what peripherals are being used and if they need to do something like clock stretching.
The ADuM1440 has 4 unidirectional channels, so it will not work for I2C bus isolation. Communication in the direction of the wireless base board is not possible in the schematics above, and the push/pull outputs of the ADuM1440 may even be causing communication issues on the MCU side.
There is an ultra-low power I2C isolator in the ADI portfolio. I recommend considering the ADuM1252.
