KW45 HW Design Recommendation

tomaru — Tue, 23 Sep 2025 09:57:58 GMT

Dear NXP Team,

I want to know what will be the issue if I did not put the external trace given in the Image below from CDD_CORE / VOUT_CORE to VDD_CORE.

I assumed it to be same so I have not interconnected it from external circuit. Will there be any problem ?

I am facing a strange behaviour, can you let me know what the issue could be ?

When I drop from 3.1V to 3V the RF Drops.
MCU seems to work as we implemented LED blink which blinks.

In some cases like below 2.5V the MCU work but RF output is wrong.
In some cases like below 2.5V the MCU stop sending Data completly and we can seee a constant power draw of around 7/8/9/12mA.

I am unable to understand as this alsways comes when we drop voltages or al low voltage.

Will there be any problem or both are same pin connected internally ?

Re: KW45 HW Design Recommendation

sofiaurueta — Tue, 23 Sep 2025 22:32:32 GMT

Hello,

Hope you are doing well.

What is the power configuration you are using in your design? And how are you powering VDD_RF?

Please see AN13831 KW45/K32W148 - Power Management Hardware section 3 "KW45/K32W148 power configurations" for the most common power configurations and considerations.

Note that any power configuration required by your application must comply with the DC voltage requirements for each power domain, which is specified in section 2.2 "Power domain rates"

The internal regulator output is given by VDD_CORE/VOUT_CORE, while the regulator input is given by VDD_CORE. It is highly recommended to connect the pins externally along with the appropriate decoupling capacitors in order to provide a feedback path and maintain voltage stability.

You can find our Minimum BoM Presentation for the recommended capacitor values and other hardware recommendations under this post: The best way to build a PCB first time right with KW45 (Automotive) or K32W1/MCXW71 (IoT/Industrial)

You could also confirm your schematic design by reviewing it with our KW45-EVK schematics.

Best Regards,

Ana Sofia.

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KW45 HW Design Recommendation

Re: KW45 HW Design Recommendation