I’m reviewing the Apalis Carrier Board Design Guide as well as the Evaluation Board and Ixora Carrier Board schematics as reference for my custom carrier board design. I’ve noticed a few minor differences between the Design Guide power supply schematics and those of the Evaluation/Ixora boards, and I just want to clarify them.
The below is from the Design Guide (Figure 63, Page 70):
This image is from the Ixora schematics (Sheet 4):
The Design Guide shows to connect TPS51120 EN (pin 12) to VREG5 (pin 21), whereas the Ixora (and Evaluation Board) schematics show EN (pin 12) connecting to PMIC_EN. Is the cause of this difference due to the fact that the Evaluation and Ixora boards have various power jumpers, etc., where the Design Guide does not? I’ve not compared the schematics in detail, so there may be other slight variations, hopefully due to the same reason.