TXS0104E-Q1: Does this IC supports partial power down function?

Jiang Boqian

Part Number: TXS0104E-Q1
Other Parts Discussed in Thread: TXB0104

Dear expert,

I choose TXS0104 for I2C level shifting. My application requires power gating for different power domains, one use case is that my host processor is powered on, but my I2C device is powered off. In this case, I need the level shifting IC support partial power down function, when either VCCA or VCCB is not present, it blocks the IO current, so that the pull up resistor on I2C will not drive my I2C device when it is not powered.

However, TXS0104's datasheet does not say about partial power down, can you help to check this? I found this function on pull pull parts like TXB0104.

I found this function on NXP's NTS0104, which I think are similar parts.

over 6 years ago

0 Clemens Ladisch over 6 years ago

Guru 319150 points

The TXS does not support partial power-down. The only way to force all I/Os to high impedance is to pull OE low.

0 ShreyasRao over 6 years ago

TI__Guru 62870 points

Hi Jiang,

As we have tested this device, the IOs go to hi-Z and disconnects the pullups during one of the power supply is turned off.
however, the datasheet doesnt guarantee the Ioff circuitry or the specs on the device.
The best way would be to have the OE to 0V as Clemens has suggested already.

Logic

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TXS0104E-Q1: Does this IC supports partial power down function?