BMP085

BMP085 BMP085 Data Digital pressure sensor sheet Bosch Sensortec Data sheet BMP085 Data sheet Order code 0 273 300 144 Package type LCC8 Data sheet revision 1.2 Release date 15 Oct 2009 Document number BST-BMP085-DS000-05 Rev. 1.2 Notes 1 sensor is functionally compatible15toOctober 2009 The BMP085 digitalPage pressure the existing Bosch Sensortec SMD500 digital pressure sensor. Product photos and pictures © Bosch Sensortec GmbH reserves all rights even in the event of industrial property rights. We reserve all rights of disposalare suchfor illustration purposes and differ from the real product’s appearance. as copying and passing on to third parties. BOSCH and the only symbol aremay registered trademarks of Robert Bosch GmbH, Germany. Specifications Specifications are subject to change without notice. are subject to change without notice. BMP085 Bosch Sensortec Data sheet BMP085 Digital pressure sensor Key features Pressure range: Supply voltage: 300 ... 1100hPa (+9000m ... -500m above sea level) 1.8 ... 3.6V (VDDA) 1.62V ... 3.6V (VDDD) LCC8 package: Robust, ceramic lead-less chip carrier (LCC) package Small footprint: 5.0mm x 5.0mm Super-flat: 1.2mm height Low power: 5µA at 1 sample / sec. in standard mode Low noise: 0.06hPa (0.5m) in ultra low power mode 0.03hPa (0.25m) ultra high resolution mode down to 0.1m (rms noise) possible - Temperature measurement included 2 - I C interface - Fully calibrated - Pb-free, halogen-free and RoHS compliant, - MSL 1 New features comparison Smaller package height Faster conversion time (standard mode each) Faster I2C data transfer Extended min. supply voltage Lower stand-by current (typ.) External clock BMP085 1.2mm 7.5ms (max.) max. 3.4MHz min. 1.8V 0.1µA not necessary SMD500 1.55mm 34ms max. 400kHz min. 2.2V 0.7µA necessary Typical applications • Enhancement of GPS navigation (dead-reckoning, slope detection, etc.) • In- and out-door navigation • Leisure and sports • Weather forecast • Vertical velocity indication (rise/sink speed) Rev. 1.2 Page 2 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Data sheet Bosch Sensortec BMB085 general description The BMP085 is the fully pin- and function compatible successor of the SMD500, a new generation of high precision digital pressure sensors for consumer applications. The universal C-code SMD500/BMP085 (“BMP085_SMD500_API”) is fully upward compatible to SMD500 and recognizes automatically the device ID. Customers already working with the SMD500 pressure sensor are invited to contact Bosch Sensortec as soon as they intend to switch-over to the BMP085 sensor for getting first-hand support. The ultra-low power, low voltage electronics of the BMP085 is optimized for use in mobile phones, PDAs, GPS navigation devices and outdoor equipment. With a low altitude noise of 2 merely 0.25m at fast conversion time, the BMP085 offers superior performance. The I C interface allows for easy system integration with a microcontroller. The BMP085 is based on piezo-resistive technology for EMC robustness, high accuracy and linearity as well as long term stability. Robert Bosch is the world market leader for pressure sensors in automotive applications. Based on the experience of over 200 million pressure sensors in the field, the BMP085 continues a new generation of micro-machined pressure sensors. Rev. 1.2 Page 3 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Data sheet Bosch Sensortec TABLE OF CONTENTS 1 ELECTRICAL CHARACTERISTICS ..........................................................................................6 2 ABSOLUTE MAXIMUM RATINGS .............................................................................................7 3 OPERATION ................................................................................................................................8 3.1 GENERAL DESCRIPTION ....................................................................................................... 8 3.2 GENERAL FUNCTION AND APPLICATION SCHEMATICS ............................................................. 8 3.3 MEASUREMENT OF PRESSURE AND TEMPERATURE.............................................................. 10 3.4 CALIBRATION COEFFICIENTS .............................................................................................. 12 3.5 CALCULATING PRESSURE AND TEMPERATURE ..................................................................... 12 3.6 CALCULATING ABSOLUTE ALTITUDE .................................................................................... 14 3.7 CALCULATING PRESSURE AT SEA LEVEL .............................................................................. 14 4 I2C INTERFACE.........................................................................................................................15 4.1 I2C SPECIFICATION ............................................................................................................ 15 4.2 DEVICE AND REGISTER ADDRESS ....................................................................................... 16 4.3 I2C PROTOCOL .................................................................................................................. 16 4.4 START TEMPERATURE AND PRESSURE MEASUREMENT ........................................................ 17 2 4.5 READ A/D CONVERSION RESULT OR E PROM DATA............................................................ 18 5 PACKAGE .................................................................................................................................19 5.1 PIN CONFIGURATION.......................................................................................................... 19 5.2 OUTLINE DIMENSIONS........................................................................................................ 20 5.2.1 Top view (pads not visible)............................................................................................20 5.2.2 Top view with lid ............................................................................................................20 5.2.3 Side view with lid ...........................................................................................................21 5.3 DEVICE MARKING .............................................................................................................. 22 5.4 TAPE ON REEL .................................................................................................................. 22 5.5 PRINTED CIRCUIT BOARD (PCB) DESIGN ............................................................................. 23 5.6 MOISTURE SENSITIVITY LEVEL AND SOLDERING ................................................................... 23 5.7 ROHS COMPLIANCY .......................................................................................................... 24 5.8 MOUNTING AND ASSEMBLY RECOMMENDATIONS ................................................................. 25 Rev. 1.2 Page 4 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Data sheet Bosch Sensortec 6 LEGAL DISCLAIMER ...............................................................................................................26 6.1 ENGINEERING SAMPLES ..................................................................................................... 26 6.2 PRODUCT USE .................................................................................................................. 26 6.3 APPLICATION EXAMPLES AND HINTS .................................................................................... 26 7 DOCUMENT HISTORY AND MODIFICATIONS......................................................................27 Rev. 1.2 Page 5 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Bosch Sensortec Data sheet 1 Electrical characteristics If not stated otherwise, the given values are maximum values over temperature/voltage range in the given operation mode. Parameter Operating temperature Supply voltage Supply current @ 1 sample / sec. 25°C Peak current Symbol TA VDD Condition +85 full accuracy 0 +65 ripple max. 50mVpp VDDIO Units °C 1.8 2.5 3.6 V 1.62 2.5 3.6 V IDDLOW ultra low power mode 3 µA IDDSTD standard mode 5 µA IDDHR high resolution mode 7 µA IDDUHR ultra high res. mode 12 µA during conversion 650 at 25°C 0.1 Ipeak Serial data clock fSCL Conversion time temperature tC_temp standard mode tc_p_low VDD = 3.3V Max -40 IDDSBM Absolute accuracy pressure Typ operational Standby current Conversion time pressure Min 1000 µA µA 3.4 MHz 3 4.5 ms ultra low power mode 3 4.5 ms tc_p_std standard mode 5 7.5 ms tc_p_hr high resolution mode 9 13.5 ms tc_p_luhr ultra high res. mode 17 25.5 ms 700 . . . 1100 hPa 0 . . . +65 °C -2.5 ±1.0 +2.5 hPa 300 . . . 700 hPa 0 . . . +65 °C -3.0 ±1.0 +3.0 hPa 300 . . . 1100 hPa -20 . . . 0 °C -4.0 ±1.5 +4.0 hPa Resolution of output data pressure 0.01 hPa temperature 0.1 °C Relative accuracy pressure 700 . . . 1100 hPa @ 25 °C ±0.2 hPa VDD = 3.3V 0 . . . 65 °C @ p const. ±0.5 hPa Noise in pressure Absolute accuracy temperature VDD = 3.3V Rev. 1.2 see table on page 10 @ 25 °C -1.5 ±0.5 +1.5 °C 0 . . . +65 °C -2.0 ±1.0 +2.0 °C Page 6 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Bosch Sensortec Data sheet Solder drifts Minimum solder height 50µm ±1.0 hPa Long term stability 12 months ±1.0 hPa 2 Absolute maximum ratings Parameter Condition Storage temperature Supply voltage all pins ESD rating HBM, R = 1.5kΩ, C = 100pF Min Max Units -40 +85 °C -0.3 +4.25 V ±2 kV 10,000 hPa Overpressure The BMP085 has to be handled as Electrostatic Sensitive Device (ESD). Rev. 1.2 Page 7 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Data sheet Bosch Sensortec 3 Operation 3.1 General description The BMP085 is designed to be connected directly to a microcontroller of a mobile device via the I2C bus. The pressure and temperature data has to be compensated by the calibration data of the E2PROM of the BMP085. 3.2 General function and application schematics The BMP085 consists of a piezo-resistive sensor, an analog to digital converter and a control unit with E2PROM and a serial I2C interface. The BMP085 delivers the uncompensated value of pressure and temperature. The E2PROM has stored 176 bit of individual calibration data. This is used to compensate offset, temperature dependence and other parameters of the sensor. • UP = pressure data (16 to 19 bit) • UT = temperature data (16 bit) Rev. 1.2 Page 8 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Bosch Sensortec Data sheet Typical application circuit: 1.8 ... 3.6V 100nF (1) Rp VDDA (1) Rp VDDD 2 E PROM µController e. g. 8 bit BMP085 EOC SDA Control Unit 2 SCL I C interface XCLR Sensor element ADC GND Note: 2 (1) Pull-up resistors for I C bus, Rp = 2.2kΩ ... 10kΩ, typ. 4.7kΩ Display Note: The BMP085 can be supplied independently with different levels of VDDA and VDDD, which is not possible with the SMD500. In case of different voltage levels, VDDA and VDDD shall have a 100nF decoupling capacitor each. Rev. 1.2 Page 9 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Bosch Sensortec Data sheet 3.3 Measurement of pressure and temperature Start For all calculations presented here an ANSI C code is available from Bosch Sensortec (“BMP085_SMD500_API”). Start temperature measurement The microcontroller sends a start sequence to start a pressure or temperature measurement. After converting time, the result value (UP or UT, respectively) can be read via the I2C interface. For calculating temperature in °C and pressure in hPa, the calibration data has to be used. These constants can be read out from the BMP085 E2PROM via the I2C interface at software initialization. wait 4.5ms Read UT Start pressure measurement The sampling rate can be increased up to 128 samples per second (standard mode) for dynamic measurement. In this case, it is sufficient to measure the temperature only once per second and to use this value for all pressure measurements during the same period. By using different modes the optimum compromise between power consumption, speed and resolution can be selected, see below table. wait (depends on mode, see below) Read UP Calculate pressure and temperature in physical units Overview of BMP085 modes, selected by driver software via the variable oversampling_setting: Mode Parameter oversampling_setting Internal number of samples Conversion time pressure max. [ms] Avg. current @ 1 sample/s typ. [µA] RMS noise typ. [hPa] RMS noise typ. [m] ultra low power 0 1 4.5 3 0.06 0.5 standard 1 2 7.5 5 0.05 0.4 high resolution 2 4 13.5 7 0.04 0.3 ultra high resolution 3 8 25.5 12 0.03 0.25 The noise data is calculated as standard deviation of 10 data points. For further information on noise characteristics see the relevant application note “Noise in pressure sensor applications”. Rev. 1.2 Page 10 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Data sheet Bosch Sensortec All modes can be performed at higher speeds, e.g. up to 128 times per second for standard mode, with the current consumption increasing proportionally to the sample rate. This way the noise can be decreased further by software averaging. Rev. 1.2 Page 11 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Data sheet Bosch Sensortec 3.4 Calibration coefficients The 176 bit E2PROM is partitioned in 11 words of 16 bit each. These contain 11 calibration coefficients. Every sensor module has individual coefficients. Before the first calculation of temperature and pressure, the master reads out the E2PROM data. The data communication can be checked by checking that none of the words has the value 0 or 0xFFFF. BMP085 reg adr Parameter MSB LSB AC1 0xAA 0xAB AC2 0xAC 0xAD AC3 0xAE 0xAF AC4 0xB0 0xB1 AC5 0xB2 0xB3 AC6 0xB4 0xB5 B1 0xB6 0xB7 B2 0xB8 0xB9 MB 0xBA 0xBB MC 0xBC 0xBD MD 0xBE 0xBF 3.5 Calculating pressure and temperature The mode (ultra low power, standard, high, ultra high resolution) can be selected by the variable oversampling_setting (0, 1, 2, 3) in the C code. The universal code SMD500/BMP085 is fully upward compatible to SMD500 and recognizes automatically the device ID. Thus, the SMD500 can be replaced "on the fly" by the BMP085 without changing hardware or software. Calculation of true temperature and pressure in steps of 1Pa (= 0.01hPa = 0.01mbar) and temperature in steps of 0.1°C. The following figure shows the detailed algorithm for pressure and temperature measurement. This algorithm is available to customers as reference C source code (“BMP085_SMD500_API”) from Bosch Sensortec and via its sales and distribution partners. Please contact your Bosch Sensortec representative for details. Rev. 1.2 Page 12 15 October 2009 © 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. Specifications are subject to change without notice. BMP085 Bosch Sensortec Data sheet Calculation of pressure and temperature for BMP085 Start example: Read calibration data 2 from the E PROM of the BMP085 2 read out E PROM registers, 16 bit, MSB first AC1 (0xAA, 0xAB) (16 bit) AC2 (0xAC, 0xAD) (16 bit) AC3 (0xAE, 0xAF) (16 bit) AC4 (0xB0, 0xB1) (16 bit) AC5 (0xB2, 0xB3) (16 bit) AC6 (0xB4, 0xB5) (16 bit) B1 (0xB6, 0xB7) (16 bit) B2 (0xB8, 0xB9) (16 bit) MB (0xBa, 0xBB) (16 bit) MC (0xBC, 0xBD) (16 bit) MD (0xBE, 0xBF) (16 bit) read uncompensated temperature value write 0x2E into reg 0xF4, wait 4.5ms read reg 0xF6 (MSB), 0xF7 (LSB) UT = MSB