VREFBUF not working on STM32WLE5JC

[grf14]

Hello everyone,

I'm trying to set up VREFBUF as an internal reference at 2.5V, but the configuration isn't working. I've seen there were issues with this (VREFBUF Enable Problem - STMicroelectronics Community), but even after rearranging the function 'HAL_SYSCFG_VREFBUF_HighImpedanceConfig(SYSCFG_VREFBUF_HIGH_IMPEDANCE_DISABLE);', it doesn't work properly. I'm using the STM32WLE5JC on the 'Lora E5 mini' development board. Here is my code:

void HAL_MspInit(void)

{

/* USER CODE BEGIN MspInit 0 */

HAL_SYSCFG_VREFBUF_HighImpedanceConfig(SYSCFG_VREFBUF_HIGH_IMPEDANCE_DISABLE);

/* USER CODE END MspInit 0 */

/* System interrupt init*/

/** Configure the internal voltage reference buffer voltage scale

*/

HAL_SYSCFG_VREFBUF_VoltageScalingConfig(SYSCFG_VREFBUF_VOLTAGE_SCALE1);

/** Enable the Internal Voltage Reference buffer

*/

HAL_SYSCFG_EnableVREFBUF();

/** Configure the internal voltage reference buffer high impedance mode

*/

HAL_SYSCFG_VREFBUF_HighImpedanceConfig(SYSCFG_VREFBUF_HIGH_IMPEDANCE_DISABLE);

/* USER CODE BEGIN MspInit 1 */

/* USER CODE END MspInit 1 */

}

Any idea what I can do?"

[grf14 · Accepted solution]

I just realized that in the Lora E5 chip the Vref+ pin is connected to Vadd pin, so that's the problem, it's not possible to use VREFBUF in this chip. In case anyone face the same problem I left here the internal connections of the STM32WLE5JC.