topic MCXN947 current design in MCX Microcontrollers

MCXN947 current design

WillieWu — Sat, 08 Mar 2025 13:17:34 GMT

Hello,

Can the IDD (max = 100mA) in the MCXN947 DataSheet be used as the maximum current value for designing the MCU power supply? Are there any additional considerations?

Thank you,

Willie

Re: MCXN947 current design

Celeste_Liu — Mon, 10 Mar 2025 08:08:14 GMT

Hello @WillieWu ,

Thanks for your post.

100 mA cannot be used as the maximum current value for designing the MCU power supply. The maximum current should exceed 100 mA, and a margin should be reserved for the power supply.
For more suggestions regarding the power supply, you can refer to the hardware design guide UG10092.

Hope it can help you.

BRs,

Celeste

Re: MCXN947 current design

WillieWu — Tue, 11 Mar 2025 03:28:13 GMT

Hi Celeste,

Thank you for your reply and for providing relevant information and suggestions.

Without considering the peripheral devices related to the MCU, what is the maximum current consumption of the MCU under maximum operating conditions?

I couldn't find this data in the relevant technical documents. Did I miss it?

Thank you,

BR,
Willie

Re: MCXN947 current design

Celeste_Liu — Tue, 11 Mar 2025 06:01:22 GMT

Hello @WillieWu ,

About this data, please refer to the section "3.2.6.1 Power Consumption Operating Behaviors' of data sheet.

Tables 20 - 25 list in detail the currents under different conditions for different power supplies.

BRs,

Celeste

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Re: MCXN947 current design

WillieWu — Fri, 14 Mar 2025 08:08:52 GMT

Hi @Celeste_Liu

The technical manual does not provide clear information on the maximum current requirements for each power group (VDD_CORE, VDD_SYS, VDD_ANA, VDD_USB, etc.). Are there any recommendations on how much current supply should be reserved?

Thank you,
BR,
Willie

Re: MCXN947 current design

Celeste_Liu — Mon, 17 Mar 2025 07:05:02 GMT

Hello wellie,

In the technical manual, only the reference voltages are provided for each power group. There are no specified current limits because the current consumption is determined by the circuit's load configuration and varies according to different modes.

Taking VDD_USB as an example, the current will increase during actual communication. It is extremely challenging for us to provide specific current values for this situation. The measured current can vary significantly depending on different configurations, such as communication frequency, communication rate, and so on. You need to run your specific configuration and conduct actual measurements on your own.

Hope it can help you.

BRs,

Celeste