The MP28167 has 4 unused pins labeled NC, RSV1, RSV2, and NC. The MP28167-A datasheet shows 4 pins on the package labeled ALT, SCL, SDA, and FB. I pray that MPS kept the other 12 pins the same, but what are the pin numbers on the MP28167-A for ALT, SCL, SDA, and FB? I’d like to lay out the board to handle both in case there are shortages or I need to increase the voltage above 5V. The MP28167 datasheet says that these 4 pins must be connected to GND or VCC, but not left floating. What are the default states for ALT, SCL, SDA, and FB on the MP28167-A? Should they be connected to GND, VCC, or left floating if unused?
Thanks.
The MP28167 datasheet recommendation should be followed for connections using that part. The SCL/SDA pins for the -A part are the RSV1/RSV2 pins on the non-A part, and the ALT/FB pins are the NC’s on the non-A part. Pin numbers:
SCL-5
SDA-6
ALT-4
FB-8
So to make the PCB work for both parts, the best solution is to use 0ohm connections to these pins to alternate nodes as floating them on the MP28167 is not allowed.