diff --git a/targets/TARGET_STM/TARGET_STM32F4/analogout_device.c b/targets/TARGET_STM/TARGET_STM32F4/analogout_device.c
index f3cd5c6779..485c27d46a 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/analogout_device.c
+++ b/targets/TARGET_STM/TARGET_STM32F4/analogout_device.c
@@ -23,6 +23,12 @@
 #include "stm32f4xx_hal.h"
 #include "PeripheralPins.h"
 
+// These variables are used for the "free" function
+static int dac_channel1_used = 0;
+#if defined(DAC_CHANNEL_2)
+static int dac_channel2_used = 0;
+#endif
+
 #if STATIC_PINMAP_READY
 #define ANALOGOUT_INIT_DIRECT analogout_init_direct
 void analogout_init_direct(dac_t *obj, const PinMap *pinmap)
@@ -62,6 +68,9 @@ static void _analogout_init_direct(dac_t *obj, const PinMap *pinmap)
     pin_function(pinmap->pin, pinmap->function);
     pin_mode(pinmap->pin, PullNone);
 
+    // Save the pin for future use
+    obj->pin = pinmap->pin;
+
     __HAL_RCC_GPIOA_CLK_ENABLE();
 
     __HAL_RCC_DAC_CLK_ENABLE();
@@ -80,6 +89,14 @@ static void _analogout_init_direct(dac_t *obj, const PinMap *pinmap)
         error("HAL_DAC_ConfigChannel failed");
     }
 
+    if (obj->channel == DAC_CHANNEL_1) {
+        dac_channel1_used = 1;
+    }
+#if defined(DAC_CHANNEL_2)
+    if (obj->channel == DAC_CHANNEL_2) {
+        dac_channel2_used = 1;
+    }
+#endif
     analogout_write_u16(obj, 0);
     HAL_DAC_Start(&obj->handle, obj->channel);
 }
@@ -96,6 +113,28 @@ void analogout_init(dac_t *obj, PinName pin)
 
 void analogout_free(dac_t *obj)
 {
+    if (obj->channel == DAC_CHANNEL_1) {
+        dac_channel1_used = 0;
+    }
+#if defined(DAC_CHANNEL_2)
+    if (obj->channel == DAC_CHANNEL_2) {
+        dac_channel2_used = 0;
+    }
+#endif
+
+    if ((dac_channel1_used == 0)
+#if defined(DAC_CHANNEL_2)
+        && (dac_channel2_used == 0)
+#endif
+        ) {
+        // Reset DAC and disable clock
+        __HAL_RCC_DAC_FORCE_RESET();
+        __HAL_RCC_DAC_RELEASE_RESET();
+        __HAL_RCC_DAC_CLK_DISABLE();
+
+        // Configure GPIO back to reset value
+        pin_function(obj->pin, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0));
+    }
 }
 
 const PinMap *analogout_pinmap()
diff --git a/targets/TARGET_STM/TARGET_STM32F4/objects.h b/targets/TARGET_STM/TARGET_STM32F4/objects.h
index be2f3b3a31..f9b991d183 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/objects.h
+++ b/targets/TARGET_STM/TARGET_STM32F4/objects.h
@@ -141,6 +141,7 @@ struct analogin_s {
 #if DEVICE_ANALOGOUT
 struct dac_s {
     DACName dac;
+    PinName pin;
     uint32_t channel;
     DAC_HandleTypeDef handle;
 };
diff --git a/targets/TARGET_STM/TARGET_STM32F7/analogout_device.c b/targets/TARGET_STM/TARGET_STM32F7/analogout_device.c
index 99425e9a7f..fba0379d78 100644
--- a/targets/TARGET_STM/TARGET_STM32F7/analogout_device.c
+++ b/targets/TARGET_STM/TARGET_STM32F7/analogout_device.c
@@ -35,6 +35,12 @@
 #include "stm32f7xx_hal.h"
 #include "PeripheralPins.h"
 
+// These variables are used for the "free" function
+static int channel1_used = 0;
+#if defined(DAC_CHANNEL_2)
+static int channel2_used = 0;
+#endif
+
 void analogout_init(dac_t *obj, PinName pin)
 {
     DAC_ChannelConfTypeDef sConfig = {0};
@@ -67,6 +73,9 @@ void analogout_init(dac_t *obj, PinName pin)
     // Configure GPIO
     pinmap_pinout(pin, PinMap_DAC);
 
+   // Save the pin for future use
+    obj->pin = pin;
+
     __GPIOA_CLK_ENABLE();
 
     __DAC_CLK_ENABLE();
@@ -85,12 +94,41 @@ void analogout_init(dac_t *obj, PinName pin)
         error("HAL_DAC_ConfigChannel failed");
     }
 
+    if (obj->channel == DAC_CHANNEL_1) {
+        channel1_used = 1;
+    }
+#if defined(DAC_CHANNEL_2)
+    if (obj->channel == DAC_CHANNEL_2) {
+        channel2_used = 1;
+    }
+#endif
     analogout_write_u16(obj, 0);
     HAL_DAC_Start(&obj->handle, obj->channel);
 }
 
 void analogout_free(dac_t *obj)
 {
+    if (obj->channel == DAC_CHANNEL_1) {
+        channel1_used = 0;
+    }
+#if defined(DAC_CHANNEL_2)
+    if (obj->channel == DAC_CHANNEL_2) {
+        channel2_used = 0;
+    }
+#endif
+    if ((channel1_used == 0)
+#if defined(DAC_CHANNEL_2)
+        && (channel2_used == 0)
+#endif
+        ) {
+        // Reset DAC and disable clock
+        __HAL_RCC_DAC_FORCE_RESET();
+        __HAL_RCC_DAC_RELEASE_RESET();
+        __HAL_RCC_DAC_CLK_DISABLE();
+
+        // Configure GPIO back to reset value
+        pin_function(obj->pin, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0));
+    }
 }
 
 const PinMap *analogout_pinmap()
diff --git a/targets/TARGET_STM/TARGET_STM32H7/analogout_device.c b/targets/TARGET_STM/TARGET_STM32H7/analogout_device.c
index e375e16a8a..b66233564a 100644
--- a/targets/TARGET_STM/TARGET_STM32H7/analogout_device.c
+++ b/targets/TARGET_STM/TARGET_STM32H7/analogout_device.c
@@ -23,6 +23,12 @@
 #include "stm32h7xx_hal.h"
 #include "PeripheralPins.h"
 
+// These variables are used for the "free" function
+static int channel1_used = 0;
+#if defined(DAC_CHANNEL_2)
+static int channel2_used = 0;
+#endif
+
 void analogout_init(dac_t *obj, PinName pin)
 {
     DAC_ChannelConfTypeDef sConfig = {0};
@@ -55,6 +61,9 @@ void analogout_init(dac_t *obj, PinName pin)
     // Configure GPIO
     pinmap_pinout(pin, PinMap_DAC);
 
+    // Save the pin for future use
+    obj->pin = pin;
+
     __GPIOA_CLK_ENABLE();
 
     if (obj->dac == DAC_1) {
@@ -80,12 +89,50 @@ void analogout_init(dac_t *obj, PinName pin)
         error("HAL_DAC_ConfigChannel failed");
     }
 
+    if (obj->channel == DAC_CHANNEL_1) {
+        channel1_used = 1;
+    }
+#if defined(DAC_CHANNEL_2)
+    if (obj->channel == DAC_CHANNEL_2) {
+        channel2_used = 1;
+    }
+#endif
     analogout_write_u16(obj, 0);
     HAL_DAC_Start(&obj->handle, obj->channel);
 }
 
 void analogout_free(dac_t *obj)
 {
+    if (obj->channel == DAC_CHANNEL_1) {
+        channel1_used = 0;
+    }
+#if defined(DAC_CHANNEL_2)    
+    if (obj->channel == DAC_CHANNEL_2) {
+        channel2_used = 0;
+    }
+#endif    
+
+    if ((channel1_used == 0) 
+#if defined(DAC_CHANNEL_2)
+        && (channel2_used == 0)
+#endif
+        ) {
+        // Reset DAC and disable clock
+        __HAL_RCC_DAC12_FORCE_RESET();
+        __HAL_RCC_DAC12_RELEASE_RESET();
+        __HAL_RCC_DAC12_CLK_DISABLE();
+    }
+
+#if defined(DAC2)
+    if (obj->dac == DAC_2) {
+        __HAL_RCC_DAC2_FORCE_RESET();
+        __HAL_RCC_DAC2_RELEASE_RESET();
+        __HAL_RCC_DAC2_CLK_DISABLE();
+    }
+#endif
+
+    // Configure GPIO back to reset value
+    pin_function(obj->pin, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0));
 }
 
 const PinMap *analogout_pinmap()