TXB0108: B port output when VccA/OE is ON and VccB is OFF.

Takahiro Saito

Expert 5455 points

Part Number: TXB0108

Hi Team,

My customer supplies the power to the device in order of VccA and VccB.

The VccA and OE is turned on at the same time because VccA and OE is tied together.

When the VccA / OE is ON and VccB is OFF, does any voltages show up on port B pins?

Regards,

Taka Saito

over 8 years ago

0 Emrys Maier over 8 years ago

TI__Guru* 97046 points

Hi Saito-san,
I have notified the appropriate applications specialist and he will be back with you soon.

0 ShreyasRao over 8 years ago

TI__Guru 62320 points

Hi Takahiro san ,

The TXB0108 has Ioff protection which prevents leakage from the I/O ports while either one of the supplies is at 0v. however, it will not apply if the Vccb is floating. Also, if Vcca > Vccb+0.5 during normal operation, there will be leakage current through the clamp diodes which needs to be avoided.

Logic

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TXB0108: B port output when VccA/OE is ON and VccB is OFF.