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
The user encountered I2C communication issues using the ADuM1440, which has unidirectional channels and is not suitable for I2C bus isolation. The support engineer recommended the ADuM1252, an ultra-low power I2C isolator, to resolve the problem.
AI Generated Content
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.
