高边开关-带容性负载
Hello UU们,有做汽车电子硬件的吗?
如果做汽车电子可能会用到很多高边开关,高边开关带的负载是让容性负载,或者是感性负载时候会比较恶劣,容性负载可能一下子不容易带起来.因为电池和负载电容上的巨大压差,高边开关上流过的电流非常之大,为此我们可以使用缓慢的打开高边开关,高边开关的EN不像是自己用Mosfet一样内阻可以缓慢的线性变化,为此Frank Pan提出用PWM渐变去控制高边开关,使负载电容上的电压缓慢增加,又不让高边开关过流保护.
但每个MCU的资源有限,可能没那么多PWM资源和定时器资源,在MCU不变的情况下,尽量的让程序复用。图1是类比高边开关的产品
图1:类比智能高边产品
以下是程序代码:
#include "main.h"
#include "string.h"
void SystemClock_Config(void);
/*注释:步骤1 定义GPIO 端口*/
#define HSD_Pin GPIO_PIN_4
#define HSD_Port GPIOG
#define HSD_Clk_Enable __HAL_RCC_GPIOG_CLK_ENABLE()
#define HSD_Pin_H HAL_GPIO_WritePin(HSD_Port,HSD_Pin,GPIO_PIN_SET)
#define HSD_Pin_L HAL_GPIO_WritePin(HSD_Port,HSD_Pin,GPIO_PIN_RESET)
/*注释:步骤2 初始化引脚*/
void HSD_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/*注释:步骤3 打开引脚时钟*/
HSD_Clk_Enable;
GPIO_InitStruct.Pin = HSD_Pin;
/*注释:步骤4 设置为输出模式*/
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
HAL_GPIO_Init(HSD_Port, &GPIO_InitStruct);
}
/*注释:步骤5 控制HSD 启动的函数*/
/* HSD State 设置高边使能或者关闭
设置任意不为0的参数就使能
参数设置为0就关闭
*/
void HSD_Ctrl(uint16_t HSDState)
{
/*
注释:步骤6
i设置最大步数 改下面1000的这个参数
j设置最大占空比比例 改下面50的这个参数
k设置每步延时步长 改下面30的这个参数
*/
uint16_t i,j,k;
if(HSDState)
{
for(i=0;i<1000;i++)
{
HSD_Pin_L;
for(j=0;j<50;j++)
for(k=0;k<30;k++);
HSD_Pin_H;
for(j=0;j<i;j++)
for(k=0;k<30;k++);
HSD_Pin_L;
}
HSD_Pin_H;
}
else
HSD_Pin_L;
}
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
HAL_Init();
SystemClock_Config();
/* USER CODE BEGIN 2 */
/*注释:步骤6 主程序初始化高边开关*/
HSD_Init();
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/*注释:步骤7 设置高边开关开*/
HSD_Ctrl(0x00);
HAL_Delay(1000);
/*注释:步骤7 设置高边开关关*/
HSD_Ctrl(0x01);
HAL_Delay(10);
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Supply configuration update enable
*/
HAL_PWREx_ConfigSupply(PWR_LDO_SUPPLY);
/** Configure the main internal regulator output voltage
*/
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE0);
while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48|RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 4;
RCC_OscInitStruct.PLL.PLLN = 275;
RCC_OscInitStruct.PLL.PLLP = 1;
RCC_OscInitStruct.PLL.PLLQ = 4;
RCC_OscInitStruct.PLL.PLLR = 2;
RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_1;
RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;
RCC_OscInitStruct.PLL.PLLFRACN = 0;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2
|RCC_CLOCKTYPE_D3PCLK1|RCC_CLOCKTYPE_D1PCLK1;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB3CLKDivider = RCC_APB3_DIV2;
RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_APB2_DIV2;
RCC_ClkInitStruct.APB4CLKDivider = RCC_APB4_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/ |
以上都比较容易看懂,其中有一段解释下,如代码2所示。
代码2:
- 其中K参数可以不用看他,单纯用于延时,不想在写个Delay函数
- j参数控制低电平持续的时间是不变的
- 随着i越来越大,HSD_Pin_H持续的比例慢慢增加
- 最大占空比就是i和j的比值,等高边打开不保护的占空比即可
- 运行到最大占空比之后高边就常高了
void HSD_Ctrl(uint16_t HSDState)
{
uint16_t i,j,k;
if(HSDState)
{
for(i=0;i<1000;i++)
{
HSD_Pin_L;
for(j=0;j<50;j++)
for(k=0;k<30;k++);
HSD_Pin_H;
for(j=0;j<i;j++)
for(k=0;k<30;k++);
HSD_Pin_L;
}
HSD_Pin_H;
}
else
HSD_Pin_L;
} |