MCXN947VNLT

Valeryi — Thu, 29 Feb 2024 09:55:34 GMT

Hello! I have a question regarding power-up sequence for controller MCXN947VNLT.

What is the exact power-up sequence must be if I'm going to use external power supply sources?

Where I can find a detailed description of the power supply sequence?

At the moment, all I could find was the following description:

If using the DCDC, the lower voltage should be selected. The DCDC is more efficient at lower voltages. The same thumb rule applies to the core LDO. The VDD_CORE must ramp after VDD. Designers must ensure that these conditions are met.
Either source can supply VDD_BAT but should power up before or with VDD_SYS. Designers must ensure that these conditions are met.
Secondary IOs VDD_P2, VDD_P3, and VDD_P4 must ramp after VDD_SYS unless they are shorted with the VDD.

What is the relation in sequence of ramp up in between VDD_CORE and VDD_SYS?

Regards, Val

Re: MCXN947VNLT

xiangjun_rong — Fri, 01 Mar 2024 03:21:57 GMT

Hi,

For the MCXN94x, there is power-up sequence requirement exactly, it is not clear in the RM.

This is the power-up sequence for MCXN94x.

The VDD_BAT is the first, VDD_SYS is the second, the VDD, VDD_Px, VDD_ANA are the third, the VDD_CORE is the last.

Hope it can help you

XiangJun Rong