芯片为STM32F407ZG,使用的是高级定时器TIM1的PWM互补PWM输出。
效果:
整体的:(通道0~3分别是CH1、CH1N、CH2、CH2N。)
细节:
CH1和CH1N的死区时间是0.375us(公式算出来应该是公式0.3us左右,跟逻辑分析仪的采样频率有关系)
CH1和CH2、CH1N和CH2N是同步的,以前做H桥的话就需要这种吧(对角同时导通),有相位差的后面再研究。
STM32CubeMX配置:
main函数
/* USER CODE BEGIN 2 */
/****普通定时器***/
HAL_TIM_PWM_Start(&htim2,TIM_CHANNEL_1);
/****高级定时器互补输出***/
HAL_TIM_PWM_Start(&htim1,TIM_CHANNEL_1);
HAL_TIM_PWM_Start(&htim1,TIM_CHANNEL_2);
HAL_TIMEx_PWMN_Start(&htim1,TIM_CHANNEL_1);
HAL_TIMEx_PWMN_Start(&htim1,TIM_CHANNEL_2);
/****寄存器方法修改比较寄存器的值,ARR的值cube配置为1000***/
TIM1->CCR1=249;
TIM1->CCR2=249;
/* USER CODE END 2 */
说明:
代码中普通定时器只是为了测试!
高级定时器与普通定时器用法有微笑区别,网上查资料总是误导,很多教程都提到要用HAL_TIMEx_PWMN_Start(&htim1,TIM_CHANNEL_1)这一句,但是只有这一句CH1N会有输出,CH1就没了,走了不少弯路。
细看高级定时器的函数名,一个是PWM、一个是PWMN,而HAL_TIMEx_PWMN_Start与HAL_TIM_PWM_Start相比多了一个Ex,所在的.c文件也不相同。猜想带Ex的可能是扩展功能吧
再来看看死区时间计算吧:
cubemx生成的代码如下:
void MX_TIM1_Init(void)
{
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
TIM_OC_InitTypeDef sConfigOC = {0};
TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};
htim1.Instance = TIM1;
htim1.Init.Prescaler = 167;
htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
htim1.Init.Period = 999;
htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim1.Init.RepetitionCounter = 0;
htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
if (HAL_TIM_Base_Init(&htim1) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim1, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_PWM_Init(&htim1) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
sConfigOC.OCMode = TIM_OCMODE_PWM1;
sConfigOC.Pulse = 99;
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(&htim1, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
sConfigOC.Pulse = 199;
if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_2) != HAL_OK)
{
Error_Handler();
}
sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_ENABLE;
sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_ENABLE;
sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
sBreakDeadTimeConfig.DeadTime = 50;
sBreakDeadTimeConfig.BreakState = TIM_BREAK_ENABLE;
sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_ENABLE;
if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)
{
Error_Handler();
}
HAL_TIM_MspPostInit(&htim1);
}
sBreakDeadTimeConfig.DeadTime = 50;这句就是死区时间了,怎么算,参考STM32F4xx中文参考手册.pdf
DeadTime 是直接写入DTG[7:0],显然,当DeadTime <128时,最高位都是0,按照最上面的那条公式算就好了,DT=50Tdtg,其中,Tdtg=tDTS=1/164Mhz(tim1接在高速时钟APB2),算出来就是DT=501/164M=0.3048us了
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