STM32H743 radio emission question

ouyang2007 · ‎2026-06-03

We set the frequency of STM32H743 SDRAM interfere with 200MHz. And test the Radio emission for device, the frequency of 200MHz is over the class A by 6dB. Change the frequency of SDRAM interface, the failure follows with the same frequency. who can give some suggestions?

mƎALLEm · ‎2026-06-03

Hello @ouyang2007 and welcome to the ST community,

AN5419 "Recommended PCB routing guidelines for STM32H723/733, STM32H725/735 and STM32H730 microcontrollers" / section "99.1 PCB stack-up" (applies also to STM32H743) suggests "the minimum configuration that can be used is 4 or 6 layers stack-up. An 8 layers boards may be required for a
very dense PCBs that have multiple SDRAM/SRAM/NOR/LCD components."

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