STM32 + SX1280 and SPI_Clk voltage level problem

Thread Starter

joseph20480

Joined Nov 15, 2023
2
Dear forum,

I have designed a board with a STM32 and SX1280. Many device is on the SPI bus (GPS module,memory and pressure sensor).
Two ways for SX1280 power supply : By the internal LDO or DC/DC buck converter. I have choose the first one.

Power Supply Schematics
The power supply is 3V3 on VDD_RADIO.

My problem is about SPI communication.
When a try to communicate with SPI device, i have seen that the SPI_CLK voltage level is not correct.
After investigation, the problem is missing when put the SX in reset mode OR i remove it...

SCR01.PNG

Yellow > SPI_CS / BLUE > SPI_CLK


SCR02.PNG
Colors are the same.
We can see that the waveform of SPI_CLK is clean.

Do you have an idea ??? What Happend ?
 
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