Changes

The VBAT voltage range of CM3 is 2.5-5V. The VBAT voltage of most CM3 IO boards is 3.3V or 5V, but the VBA voltage of CM4 is only 5V. When the VBAT of the CM3 IO board used is 3.3V, a DC circuit is needed; but if the VBAT of the CM3 IO board is 5V, the DC voltage will produce howling because it does not need to be boosted;

[[File:CM3.jpg|CM3]]

But this issue has been solved in the current production batch.