Our customer have question that their case is in cut the ADAU1451 power off in standby mode.
They would confirm I2C state if we cut the ADAU1451 power off.
It should high impedance? Or short to GND?
Since you used the term "Standby mode", I want to know if you are talking about holding the part in reset using the reset pin? Or are you talking about having most of the part shutdown in software using register settings? Or are you removing power from the actual power pins? If so then which power pins are you removing power? IOVDD? AVDD? DVDD?
Our customer would remove all power on ADAU1451, including IOVDD, AVDD and DVDD.
Other I2C slave still working in their product standby mode.
They concern it should crash on the I2C if it is not high impedance on the ADAU1451 I2C pin.
They already start layout but still cannot get a solid answer on the schematic, it is urgent,
so please kindly help this question.
They will have to isolate the I2C lines with a bus repeater or something similar. This is because when the IOVDD is missing then any voltage above ~0.3V will forward bias the ESD diodes and cause current to flow into the IOVDD circuit. It will try to power up the part through the ESD diodes on the I2C pins.
Thank you very much for your kindly help.
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