Part Number: TXS0102
We develop a new product where we need to traslate I2C from 3.6V (VCCA) to 2.8V(VCCB). Attach the schematic we use. It compose from one LDO with enable from MCU.
We see in the page 19 of the datasheet "SCES640I" TXS0102 the following:
"The output-enable (OE) input circuit is designed so that it is supplied by VCCA and when the (OE) input is low, all outputs are placed in the high-impedance state. To ensure the high-impedance state of the outputs during power up or power down, the OE input pin must be tied to GND through a pulldown resistor and must not be enabled until VCCA and VCCB are fully ramped and stable".
That mean we need to use another control pin from MCU to control the OE pin of the level traslator to enable level shifter when VCCA and VCCB is stable and disable the level shifter before turning off the LDO regulator or we can use the attached circuit??
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In reply to Blindu Marcel:
If you do not care about the state of the outputs during power up or power down, then you can connect OE directly to VCCA.
(The TXS is a passive switch; the worst that you could see would be spikes that are much shorter than an I²C clock cycle.)
In reply to Clemens Ladisch:
To add to what Clemens stated, if left permanently enabled you will likely just see the I/O track Vcc during power up due to the internal pull-ups. To echo Clemens, this will be fine as long as the system doesn't care about the state of the I/O when its powering up.
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