TXB0108: VCCB ON/OFF

hibi masayuki

Part Number: TXB0108

Is it okay to turn the VCCB power ON/OFF while the VCCA power is ON?
Turns CE pin OFF when VCCB power is OFF.

3 months ago

0 Clemens Ladisch 3 months ago

Guru 267510 points

A current can flow into VCCA and out of VCCB; see Biasing Requirements for TXS, TXB, and LSF Auto-Bidirectional Translators.

0 hibi masayuki 3 months ago in reply to Clemens Ladisch

Prodigy 10 points

Is it written on the TXS0108E catalog as shown below?

"No power-supply sequencing required – either
VCCA or VCCB can be ramped first"

0 Clemens Ladisch 3 months ago in reply to hibi masayuki

Guru 267510 points

The TXS/TXB will not be damaged by this. The question is whether your circuit can handle the current flowing out of VCCB.

0 Jack Guan 3 months ago

TI__Mastermind 22191 points

Hey Hibi,

The app note Clemens' shared documents the leakage current present at VCCB whenever VCCA> VCCB. We would need to make sure that the P.S can handle this leakage.

Note that this device supports partial power down mode applications where VCCA and/ or VCCB is powered down and at 0V, resulting in the outputs being disabled and minimizing current backflow through the device.

Regards,

Jack

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TXB0108: VCCB ON/OFF