This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN74LVC4245A: Pin1 voltage is abnormal

Part Number: SN74LVC4245A
Other Parts Discussed in Thread: SN74LVC541A

Dear TI Expert~

This chip SN74LVC4245A is used for serial port to receive RX level conversion, and converts 5V to 3V3, so that two devices can communicate normally.


When the master device is in the shutdown state, that is, the +V3.3 and 5V levels of the above figure are all 0; the slave device is turned on, and the RXD_A and other receiving terminals are all 5V high level; the current enters the SN74LVC4245APWR through the pin3. Then flow to pin1 and measure pin1 to 2.5V. However, the master device is not powered on and pin1 should be at 0 level.
This problem exists with machines that use the SN74LVC4245APWR. The current interim measure is to add a diode isolation between the PIN1 to 5V supplies. Please help resolve this issue, thanks.

Thank you,
Robin