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.

SN74LXC8T245-Q1: Ways to test functionality of level shifter?

Part Number: SN74LXC8T245-Q1
Other Parts Discussed in Thread: SN74LXC8T245,
Hi all, I would like to seek advice on the best and most straightforward way of verifying the voltage translation functions of a level shifter part on a test backplane PCB design prior to mating boards together. The level shifter part used to convert SPI signals between a mezzanine board at 3.3V logic level and an FPGA at 1.5V logic levels is SN74LXC8T245 from TI. Schematic snippet attached for reference. I would like to avoid damage of downstream devices during component level testing/checkout, but having to lift output source-series resistors can be a pain to isolate just the level shifter. Would a simple way to test 3.3V -> 1.5V be to use a power supply or signal generator to inject these logic levels at the input port and probe at the output port? Any recommendations are welcome.
  • Yes, when the device is powered, you can apply voltages at the inputs and probe the outputs.

    If you do not want to lift the resistors, you have to use some other mechanism to disconnect the signals. But the SN74LXC8T245-Q1 itself cannot help you with this.