the VR_PA voltage is smaller than 3.1V in HP configuration

[ngodoanvan]

Hi,

I designed the hardware like the firgure below,

my schematic below,

the VDD connected to the VDDPA pin.

VR_PA voltage is 1.7 - 1.9V.

when Lora transmit the VR_PA voltage is smaller than 3.1V.

Please support me. Thank you very much

[Louis AUDOLY]

Hello @Ngô Vạn​ ,

Can you tell me if you well configure your software to be in high power (22dBm) ? And if you have well selected the HP output for your measurements ?

Have you measured your output power ?

Thank you for your answers

Best regards

Louis

[ngodoanvan]

In schematic reference file the C17 capacitor's value is 68pF. I tried to replace C17 capacitor's value to 10uF. My application work correctly. What wrong in my design ?Please support me. Thanks