Voltage Level on I2C ADAU1787/SSM3525

Hello,

I am working on a configuration with both eval boards for ADAU1787 and SSM3525.

I plugged the Eval-ADUSB2Z in parallel on both boards and everything works fine.( I have only one USB cable and a small homemade wire to distribute the signals)

I am now designing my PCB and my microcontroller is working in 3.3V. I would like to use one I2C port of the microcontroller to communicate with both ADAU1787 and SSM3525.

Looking to the datasheet of SSM3525, it allows to work with 5V on the SDA/SCL pins. Looking to ADAU1787, it is only specified that the Digital I/O accept IOVDD +/- 0.3 which means max 1.8V + 0.3V.

My question is :

Is it possible to link the I2C of my microcontroller in 3.3V directly onto the ADAU 1787 or do I have to put a level shifter ?

I wonder why the parallel connection is working with the eval boards because it seems that it is working in 3.3V already...

I hope it is understandable.

Thanks in advance for your help.

YBecher.

Speaker Amplifiers

ADAU1787

SSM3525

Integrated/Special Purpose A/D Converters

Class-D Audio Amplifiers

Audio CODECs

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