diff --git a/README.md b/README.md
index aea2bc5..f5042bf 100644
--- a/README.md
+++ b/README.md
@@ -7,9 +7,9 @@ The sensor driver package includes bme680.h, bme680.c and bme680_defs.h files
 ## Version
 File          | Version | Date
 --------------|---------|-------------
-bme680.c      |  3.5.3	| 30 Oct 2017
-bme680.h      |  3.5.3	| 30 Oct 2017
-bme680_defs.h |  3.5.3	| 30 Oct 2017  
+bme680.c      |  3.5.5	| 20 Nov 2017
+bme680.h      |  3.5.5	| 20 Nov 2017
+bme680_defs.h |  3.5.5	| 20 Nov 2017  
 
 ## Integration details
 * Integrate bme680.h, bme680_defs.h and bme680.c file in to your project.
diff --git a/bme680.c b/bme680.c
index b457dac..b68e20e 100644
--- a/bme680.c
+++ b/bme680.c
@@ -40,8 +40,8 @@
  * patent rights of the copyright holder.
  *
  * File		bme680.c
- * @date	30 Oct 2017
- * @version	3.5.3
+ * @date	20 Nov 2017
+ * @version	3.5.5
  *
  */
 
@@ -596,9 +596,15 @@ int8_t bme680_get_sensor_mode(struct bme680_dev *dev)
 void bme680_set_profile_dur(uint16_t duration, struct bme680_dev *dev)
 {
 	uint32_t tph_dur; /* Calculate in us */
+	uint32_t meas_cycles;
+	uint8_t os_to_meas_cycles[6] = {0, 1, 2, 4, 8, 16};
+
+	meas_cycles = os_to_meas_cycles[dev->tph_sett.os_temp];
+	meas_cycles += os_to_meas_cycles[dev->tph_sett.os_pres];
+	meas_cycles += os_to_meas_cycles[dev->tph_sett.os_hum];
 
 	/* TPH measurement duration */
-	tph_dur = ((uint32_t) (dev->tph_sett.os_temp + dev->tph_sett.os_pres + dev->tph_sett.os_hum) * UINT32_C(1963));
+	tph_dur = meas_cycles * UINT32_C(1963);
 	tph_dur += UINT32_C(477 * 4); /* TPH switching duration */
 	tph_dur += UINT32_C(477 * 5); /* Gas measurement duration */
 	tph_dur += UINT32_C(500); /* Get it to the closest whole number.*/
@@ -615,9 +621,15 @@ void bme680_set_profile_dur(uint16_t duration, struct bme680_dev *dev)
 void bme680_get_profile_dur(uint16_t *duration, const struct bme680_dev *dev)
 {
 	uint32_t tph_dur; /* Calculate in us */
+	uint32_t meas_cycles;
+	uint8_t os_to_meas_cycles[6] = {0, 1, 2, 4, 8, 16};
+
+	meas_cycles = os_to_meas_cycles[dev->tph_sett.os_temp];
+	meas_cycles += os_to_meas_cycles[dev->tph_sett.os_pres];
+	meas_cycles += os_to_meas_cycles[dev->tph_sett.os_hum];
 
 	/* TPH measurement duration */
-	tph_dur = ((uint32_t) (dev->tph_sett.os_temp + dev->tph_sett.os_pres + dev->tph_sett.os_hum) * UINT32_C(1963));
+	tph_dur = meas_cycles * UINT32_C(1963);
 	tph_dur += UINT32_C(477 * 4); /* TPH switching duration */
 	tph_dur += UINT32_C(477 * 5); /* Gas measurement duration */
 	tph_dur += UINT32_C(500); /* Get it to the closest whole number.*/
diff --git a/bme680.h b/bme680.h
index 56eb7a8..7196058 100644
--- a/bme680.h
+++ b/bme680.h
@@ -40,8 +40,8 @@
  * patent rights of the copyright holder.
  *
  * @file	bme680.h
- * @date	30 Oct 2017
- * @version	3.5.3
+ * @date	20 Nov 2017
+ * @version	3.5.5
  * @brief
  *
  */
diff --git a/bme680_defs.h b/bme680_defs.h
index 3afb94c..0cf581b 100644
--- a/bme680_defs.h
+++ b/bme680_defs.h
@@ -39,9 +39,9 @@
  * No license is granted by implication or otherwise under any patent or
  * patent rights of the copyright holder.
  *
- * @file    bme680_defs.h
- * @date	30 Oct 2017
- * @version	3.5.3
+ * @file	bme680_defs.h
+ * @date	20 Nov 2017
+ * @version	3.5.5
  * @brief
  *
  */
@@ -111,7 +111,7 @@
 #define BME680_CHIP_ID  UINT8_C(0x61)
 
 /** BME680 coefficients related defines */
-#define BME680_COEFF_SIZE		UINT8_C(0x41)
+#define BME680_COEFF_SIZE		UINT8_C(41)
 #define BME680_COEFF_ADDR1_LEN		UINT8_C(25)
 #define BME680_COEFF_ADDR2_LEN		UINT8_C(16)
 
diff --git a/changelog.md b/changelog.md
index c777229..fd357da 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,14 @@
 # Change Log
 All notable changes to the BME680 Sensor API will be documented in this file.
+
+## v3.5.5, 20 Nov 2017
+### Changed
+ - Updated the buffer size in "get_calib_data" API
+
+## v3.5.4, 16 Nov 2017
+### Changed
+ - Updated the set/get gas profile duration logic
+
 ## v3.5.3, 30 Oct 2017
 ### Changed
  - Changed the compensation equation formulae to use shifting operation
@@ -21,14 +30,12 @@ All notable changes to the BME680 Sensor API will be documented in this file.
  - Updated documentation for the type definitions
  - Removed mode check for get sensor data and setting and getting profile dur
  
-
 ## v3.5.0, 28 Jun 2017
 ### Changed
 - Fixed bug with getting and setting mem pages
 - Changed initialization sequence to be more robust
 - Added additional tries while reading data in case of inadequate delay
 
-
 ## v3.4.0, 8 Jun 2017
 ### Changed
 - Modified the bme680_get_sensor_data API. User has to now pass the struct that stores the data rather than retrieving from the bme680_dev structure.
@@ -47,5 +54,4 @@ All notable changes to the BME680 Sensor API will be documented in this file.
 
 ## v3.2.1, 17 May 2017
 ### Added
-- Took the reference as base version 3.2.1 of BME680 sensor and added.
-
+- Took the reference as base version 3.2.1 of BME680 sensor and added.
\ No newline at end of file