I am currently using SN74ABT5402ADW as a buffer and level shifter for my ADC, however, the datasheet does not explicitly say that it can be used as a level shifter. I provide it with 5V power, but the input signals (out of the ADC) are 3.3V. The performance is bad: when I scope the signal on the output pins, the signal is not even close to look like binary HI/LOW. It does have rise/fall edges, but HI/LOW values seem to float, especially at xxx1111 to xx10000 transitions. I suspect that it does not convert the signal from 3.3V to 5V properly. Could anyone tell me if I am misusing it as described, and what can I do to make it work?
Measured signal at the input (yellow) and the output (blue) of '5402A when it is not connected to the NI connector blocks.
Measured signal at the input (yellow) and the output (blue) of '5402Awhen it is connected to the NI connector blocks via 8" unshielded wires.
Power at the power pin of the '5402A:
All ground pins on both NI connector blocks are interconnected internally.
- Cable 1-3: Digital lines
- Cable 4: trigger signal and GND wire
- Cable 5: GND wire