TCA9617A: VCCA margin over VCCB

Will Wang47

Part Number: TCA9617A

Hi team,

Customer get one question about TCA9617A. They need that TCA9617A VCCA should not be higher than VCCB. However, under certain case, they will connect two different "3.3V" voltage. But because of the output voltage accuracy, there still may be several tens of mV difference between VCCA and VCCB, VCCA get possibility higher than VCCB. So they want to check with us, what's the margin over VCCA than VCCB? Do we have a general experience for this?

Thanks and Best Regards,

Will

over 4 years ago

0 Clemens Ladisch over 4 years ago

Guru 316940 points

I expect there to be a diode. A difference of up to 0.5 V should be harmless.

+1 BOBBY over 4 years ago in reply to Clemens Ladisch

TI__Guru 73181 points

Clemen's assessment is correct (as usual). The A version of our device has an issue where the A side can backbias into B side through ESD diodes. You should try to aim to be below that 0.5V threshold to avoid leakage into B side from A side.

-Bobby

0 Will Wang47 over 4 years ago in reply to BOBBY

TI__Expert 7710 points

Hi Bobby,

Does the B version get this ESD diodes and would get this problem?

Best Regards,

Will

+1 BOBBY over 4 years ago in reply to Will Wang47

TI__Guru 73181 points

B version was designed specifically to fix the issue A version has (Back biasing ESD diodes). I still would not suggest having A side exceed B side too much as the device technically was not designed/validated/tested with that condition.

-Bobby

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TCA9617A: VCCA margin over VCCB