STM32L475RC glitch in fixed timer PWM

Hello,

I have a power converter device controlled by a STM32L475RC. One part of the control requires a constant PWM of 70kHz of 300ns (Ton).

Although this pwm is never modified,and doesn't use interrupts or DMA modules, periodically it produces a glitch in its output (like in attached image). Specially when there is high noise of power conversion.

I suppose that another peripheral is producing this error, but I can't figure out which one. (Another timer?, a I2C by DMA communication?,...)

Any one has ever seen some similar, and know which is the cause?

Thanks in advance

/* TIM8 init function */

void MX_TIM8_Init(void)

{

 /* USER CODE BEGIN TIM8_Init 0 */

 /* USER CODE END TIM8_Init 0 */

 TIM_MasterConfigTypeDef sMasterConfig = {0};

 TIM_OC_InitTypeDef sConfigOC = {0};

 TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};

 /* USER CODE BEGIN TIM8_Init 1 */

 /* USER CODE END TIM8_Init 1 */

 htim8.Instance = TIM8;

 htim8.Init.Prescaler = 0;

 htim8.Init.CounterMode = TIM_COUNTERMODE_UP;

 htim8.Init.Period = 1143;

 htim8.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;

 htim8.Init.RepetitionCounter = 0;

 htim8.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;

 if (HAL_TIM_PWM_Init(&htim8) != HAL_OK)

 {

   Error_Handler();

 }

 sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;

 sMasterConfig.MasterOutputTrigger2 = TIM_TRGO2_RESET;

 sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;

 if (HAL_TIMEx_MasterConfigSynchronization(&htim8, &sMasterConfig) != HAL_OK)

 {

   Error_Handler();

 }

 sConfigOC.OCMode = TIM_OCMODE_PWM1;

 sConfigOC.Pulse = 24;

 sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;

 sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;

 sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;

 sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;

 sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;

 if (HAL_TIM_PWM_ConfigChannel(&htim8, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)

 {

   Error_Handler();

 }

 sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;

 sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;

 sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;

 sBreakDeadTimeConfig.DeadTime = 0;

 sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;

 sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;

 sBreakDeadTimeConfig.BreakFilter = 0;

 sBreakDeadTimeConfig.Break2State = TIM_BREAK2_DISABLE;

 sBreakDeadTimeConfig.Break2Polarity = TIM_BREAK2POLARITY_HIGH;

 sBreakDeadTimeConfig.Break2Filter = 0;

 sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;

 if (HAL_TIMEx_ConfigBreakDeadTime(&htim8, &sBreakDeadTimeConfig) != HAL_OK)

 {

   Error_Handler();

 }

 /* USER CODE BEGIN TIM8_Init 2 */

 /* USER CODE END TIM8_Init 2 */

 HAL_TIM_MspPostInit(&htim8);

}

// 70KHz (Ton 300ns)

HAL_TIM_PWM_Start(&htim8, TIM_CHANNEL_1);