NTS0102: can it handle Vcc(a) > Vcc(b) when not operating?

[brenconsult]

We have an application in which normal operation, during which I2C communication can occur, has Vcc(a) = 1.8 V and Vcc(b) = 3.0 V.  

There is another configuration (battery charging), during which Vcc(a) would be 5.0 V instead of 1.8 V.  In this configuration there might be I2C activity on the 3.0 V side (the B side) of the chip at times, but there will be no I2C device on the A side and thus no expectation of proper operation by the NTS0102.

My impression from the datasheet (Section 14.5 -- Power Up) is that this won't damage the device, but we need to be sure: there be any damage in this second configuration, or is it simply that the chip will not operate properly until Vcc(a) falls below Vcc(b) again?

Thanks,
Scott 

[TomasVaverka]

Hello Scott,

In theory, the device should not be damaged, as Vcca has 6.5V max limiting value.

What is the state of OE during 2nd configuration? It would be better if you could drive OE low to disable the device at this condition.

Best regards,

Tomas

[brenconsult]

Hello Tomas,

Yes, we should be able to disable the device under that condition.

Thank you!

Scott