Datasheet

BMP280 Digital Pressure Sensor

Page 44

BST-BMP280-DS001-19 | Revision 1.19 | January 2018

Bosch Sensortec

© Bosch Sensortec GmbH reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such as copying and passing on to third

parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.

Note: Specifications within this document are subject to change without notice. Not intended for publication.

7.6 Mounting and assembly recommendations

In addition to “Handling, soldering & mounting instructions BMP280”, the following

recommendations should be taken into consideration when mounting a pressure sensor on a

printed-circuit board (PCB):

 The clearance above the metal lid shall be 0.1mm at minimum.

 For the device housing appropriate venting needs to be provided in case the ambient

pressure shall be measured.

 Liquids shall not come into direct contact with the device.

 During operation the sensor chip is sensitive to light, which can influence the accuracy of

the measurement (photo-current of silicon). The position of the vent hole minimizes the

light exposure of the sensor chip. Nevertheless, BST recommends to avoid the exposure

of BMP280 to strong light sources.

 Soldering may not be done using vapor phase processes since the sensor might be

damaged.

7.7 Environmental safety

7.7.1 RoHS

The BMP280 sensor meets the requirements of the EC restriction of hazardous substances

(RoHS) directive, see also:

Directive 2011/65/EU of the European Parliament and of the Council of 8 June 2011 on

the restriction of the use of certain hazardous substances in electrical and electronic

equipment.

7.7.2 Halogen content

The BMP280 is halogen-free. For more details on the analysis results please contact your Bosch

Sensortec representative.

7.7.3 Internal package structure

Within the scope of Bosch Sensortec’s ambition to improve its products and secure the mass

package of the BMP280.

While Bosch Sensortec took care that all of the technical packages parameters are described

above are 100% identical for all sources, there can be differences in the chemical content and

the internal structural between the different package sources.

However, as secured by the extensive product qualification process of Bosch Sensortec, this has

no impact to the usage or to the quality of the BMP280 product.

8. Appendix 1: Computation formulae for 32 bit systems

8.1 Compensation formula in floating point

Please note that it is strongly advised to use the API available from Bosch Sensortec to perform

readout and compensation. If this is not wanted, the code below can be applied at the user’s risk.

Both pressure and temperature values are expected to be received in 20 bit format, positive,

stored in a 32 bit signed integer.