> For the complete documentation index, see [llms.txt](https://nxp.gitbook.io/nxp-cup/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nxp.gitbook.io/nxp-cup/2025-fall-2026-nxp-cup-mcxn947/assembly-and-hardware/electrical-connections/frdm-mcxn947/j4-header.md).

# J4 Header

<figure><img src="https://2412084329-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-L9GLtaxrQtBdBRsFIJB%2Fuploads%2FRBmGawMW6ddWormCn1Jm%2Fimage.png?alt=media&amp;token=5edcd95b-908c-44b3-a09b-30c0cb835a42" alt="" width="375"><figcaption></figcaption></figure>

This header only provides the connection between the board and the voltage regulator's 5-volt power supply.

The diode protects the FRDM-MCXN947 board from reverse voltage. If the power is connected the wrong way, the diode blocks it and keeps the board safe.

For a 5V, 500mA setup, use a Schottky diode rated for at least 1A and 20V, like the 1N5819 or SS14.