KW45 MCU heating up

Sadeed — Tue, 10 Jun 2025 15:51:40 GMT

We have assembled Two KW45 boards, During Board bringup we are facing few issues, Which are as follows:

As per the attached schematics:

-> The KW45 ic started heating up when board was powered On and the board was drawing 0.45 Amps at 12Volts. After some Debugging activity, I have found that when R15 is removed then its drawing only 10 mA. The heating issue happens when I mount that resistor.
When R15 is removed, I have measured 1.8V at pin 21 on KW45 ic.

-> The voltage on MCU Reset pin is 2.299V; 3.3V rail has less than 100mV ripple. I have observed some kind of oscillation on that pin.

-> We have referred to page 749 found in KW45 Reference manual.

-> we are using KW45B41Z53AFTBR

-> On 5V section, I am getting 5.4V, as we have adjusted it for other requirements and in 3.3V section, it is 3.3V.

Could you please Verify the Schematics for any kind of improvement?

______
Thanks & Regards

Sadeed

Re: KW45 MCU heating up

RafaR — Tue, 10 Jun 2025 17:17:45 GMT

Hello Sadeed

Sorry in this community we don’t support the KW series

if you want ask more questions about KW series, please create a post on Wireless MCU - NXP Community. That's the correct channel, the supporters there will help you better.

I hope this information has helped you.

Have a great day and best of luck.

topic KW45 MCU heating up in Power Management

KW45 MCU heating up

Re: KW45 MCU heating up