MS5540-CM Measurement Specialties Inc., MS5540-CM Datasheet
MS5540-CM
Specifications of MS5540-CM
Related parts for MS5540-CM
MS5540-CM Summary of contents
Page 1
... Compared to MS5534A the pressure range (measurement down to 10 mbar) has been improved. The MS5540C is fully software compatible to the MS5534C and previous versions of MS5540. In addition, the MS5540C is from its outer dimensions compatible to the MS54XX series of pressure sensors. Compared to the previous version the ESD sensitivity level has been improved to 4kV on all pins ...
Page 2
... Storage temperature Overpressure NOTES 1) Storage and operation in an environment of dry and non-corrosive gases. 2) The MS5540C is qualified referring to the ISO Standard 2281 and can withstand an absolute pressure of 11 bar in salt water or 100 m water respectively. DA5540C_001 0005540C1193 ECN 1037 Fig. 2: Pin configuration of MS5540C. ...
Page 3
... During conversion the sensor will be switched on and off in order to reduce power consumption; the total on time within a conversion is about 2 ms. 3) This value can be reduced by switching off MCLK while MS5540C is in standby mode strongly recommended that a crystal oscillator be used because the device is sensitive to clock jitter. A square-wave form of the clock signal is a must ...
Page 4
ELECTRICAL CHARACTERISTICS DIGITAL INPUTS Parameter Symbol Input High Voltage V IH Input Low Voltage V IL Signal Rise Time t r Signal Fall Time t f DIGITAL OUTPUTS Parameter Symbol Output High Voltage V OH Output Low Voltage V OL ...
Page 5
... PRESSURE OUTPUT CHARACTERISTICS With the calibration data stored in the interface IC of the MS5540C the following characteristics can be achieved: Parameter Resolution Absolute Pressure Accuracy Relative Pressure Accuracy Relative Pressure Error over Temperature Long-term Stability Maximum Error over Supply Voltage NOTES 1) A stable pressure reading of the given resolution requires taking the average subsequent pressure values due to noise of the ADC ...
Page 6
... Absolute Pressure Accuracy after Calibration, 2nd order compensation 100 200 DA5540C_001 0005540C1193 ECN 1037 ADC-value D1 vs Pressure (typical) 300 400 500 600 700 ...
Page 7
... DA5540C_001 0005540C1193 ECN 1037 20 40 Temperature (° C) Pressure Error Accuracy vs temperature (typical Temperature (° C) February 20th, 2008 Temperature error (standard calculation) Temperature error (with 2nd order calculation Perror(1000,1st order) Perror(1000,2nd order) Perror(800,1st order) Perror(800,2nd order) Perror(300,1st order) Perror(300,2nd order) ...
Page 8
... DA5540C_001 0005540C1193 ECN 1037 Pressure error vs supply voltage (typical) 2.8 3 3.2 Voltage (V) Temperature error vs supply voltage (typical) 2.8 3 3.2 Voltage (V) February 20th, 2008 1000mbar 800mbar 3.4 3.6 300mbar 3.4 3 ...
Page 9
... FUNCTION GENERAL The MS5540C consists of a piezoresistive sensor and a sensor interface IC. The main function of the MS5540C is to convert the uncompensated analogue output voltage from the piezoresistive pressure sensor to a 16-Bit digital value, as well as providing a 16-Bit digital value for the temperature of the sensor. ...
Page 10
... C3: Temperature coefficient of pressure sensitivity (10 Bit) C4: Temperature coefficient of pressure offset C5: Reference Temperature C6: Temperature coefficient of the temperature Read digital pressure value from MS5540 D1 (16 Bit) Read digital temperature value from MS5540 D2 (16 Bit) Calculate calibration temperature UT1 = 8*C5+20224 Calculate actual temperature Difference between actual temperature and reference ...
Page 11
... In order to obtain best accuracy over the whole temperature range recommended to compensate for the non-linearity of the output of the temperature sensor. This can be achieved by correcting the calculated temperature and pressure by a second order correction factor. The second-order factors are calculated as follows: TEMP < 200 ...
Page 12
... Fig. 1. The SCLK (Serial clock) signal initiates the communication and synchronises the data transfer with each Bit being sampled by the MS5540C on the rising edge of SCLK and each Bit being sent by the MS5540C on the rising edge of SCLK. The data should thus be sampled by the microcontroller on the falling edge of SCLK and sent to the MS5540C with the falling edge of SCLK. The SCLK-signal is generated by the microprocessor’ ...
Page 13
Conversion start for temperature measurement and ADC-data-out "D2": start of conversion sequence: START+T-measurement Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Bit8 Bit9 Start-bit Setup-bits Stop-bit Calibration data read out sequence for word 1/ word 3: sequence: coefficient read + ...
Page 14
... LIGHT SENSITIVITY The MS5540C is protected against sunlight by a layer of white gel. It is, however, important to note that the sensor may still be slightly sensitive to sunlight, especially to infrared light sources. This is due to the strong photo effect of silicon ...
Page 15
... DECOUPLING CAPACITOR Particular care must be taken when connecting the device to power supply µF tantalum capacitor must be placed as close as possible of the MS5540C's VDD pin. This capacitor will stabilise the power supply during data conversion and thus, provide the highest possible accuracy. APPLICATION EXAMPLE: ALTIMETER SYSTEM USING MS5540C MS5540C is a circuit that can be used in connection with a microcontroller in mobile altimeter applications ...
Page 16
... DEVICE PACKAGE OUTLINES Fig. 8: Device package outlines of MS5540C. DA5540C_001 0005540C1193 ECN 1037 February 20th, 2008 16 ...
Page 17
... In addition to this the MS5540C is filled with silicone gel covering the sensor and the bonding wires. The O-ring (or O-rings) shall be placed at the outer diameter of the metal cap. This method avoids mechanical stress because the sensor can move in vertical direction ...
Page 18
... ORDERING INFORMATION Product Code Product Miniature MS5540-CM Barometer Module with metal cap FACTORY CONTACTS Intersema Sensoric SA Ch. Chapons-des-Prés 11 CH-2022 BEVAIX SWITZERLAND NOTICE Intersema reserves the right to make changes to the products contained in this data sheet in order to improve the design or performance and to supply the best possible products. Intersema assumes no responsibility for the use of any circuits shown in this data sheet, conveys no license under any patent or other rights unless otherwise specified in this data sheet, and makes no claim that the circuits are free from patent infringement ...