MS5541C TEC | Alldatasheet
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SENSOR SOLUTIONS ///MS5541C Page 1 09/2015 MS5541C Miniature 14 bar Module SPECIFICATIONS 0 – 14 bar absolute pressure range 6 coefficients for software compensation stored on-chip Piezoresistive silicon micromachined sensor Integrated miniature pressure sensor 6.2 x 6.4 mm 16 Bit ADC 3-wire serial interface 1 system clock line (32.768 kHz) Low voltage and low power consumption High Endurance (HM version) The MS5541C is the miniature version of MS5535C pressure sensor module. The MS5541-HM is the high endurance pad technology version of MS5541C pressure sensor module. It contains a precision piezoresistive pressure sensor and an improved version of the 16 Bit Micropower Sensor interface IC known from the MS5535C. Compared to the previous version the ESD sensitivity has been improved to 4kV on all pins. In addition to this the MS5541C is from its outer dimensions compatible to the MS54xx series of pressure sensors. It uses an antimagnetic polished stainless steel ring for sealing with O-ring. The sensor provides 16 Bit pressure and temperature data via a 3 wire serial interface that can be easily interfaced with 4 Bit low power microcontrollers. 64 Bit of factory programmed PROM provides calibration data for a highly accurate pressure and temperature calculation. The MS5541C is fully software compatible to the MS5535C and previous versions of MS5541.
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 2
FEATURES
Diving computers and watches Mobile water depth and measurement systems High endurance pad technology (HM version) TECHNICAL DATA Sensor Performances (VDD = 3 V) Pressure Min Typ Max Unit Range 0 14 bar ADC 16 bit Resolution 1.2 mbar Accuracy 0°C to +40°C, 0 to 10 bar -50 +20 mbar Accuracy -40°C to +85°C 0 to 10 bar -60 +180 mbar Response time 35 ms Long term stability 20 mbar/yr Temperature Min Typ Max Unit Range -40 +85 °C Resolution 0.005 0.015 °C Accuracy -0.8 +0.8 °C FUNCTIONAL BLOCK DIAGRAM VDD GND MCLK SCLK DOUT DIN Input MUX ADC Digital Interface Memory (PROM) 64 bits SENSOR SGND +IN -IN dig. Filter Sensor Interface IC
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 3 PERFORMANCE SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS Parameter Symbol Conditions Min Max Unit Notes Supply voltage VDD Ta = 25 °C -0.3 4 V Storage temperature TS -40 +85 °C 1 Overpressure P Ta = 25 °C 30 bar 2 NOTES 1) Storage and operation in an environment of dry and non-corrosive gases. 2) The MS5541C is qualified referring to the ISO 6425 standard and can withstan d an absolute pressure of 30 bar in salt water.
ELECTRICAL CHARACTERISTICS
(Ta = 25 °C, VDD = 3.0 V unless noted otherwise) Parameter Symbol Conditions Min Typ Max Unit Operating pressure range p 0 14 bar Supply voltage VDD 2.2 3.0 3.6 V Supply current, average (1) during conversion (2) standby (no conversion) Iavg Isc Iss VDD = 3.0 V 0.1 µA mA µA Current consumption into MCLK (3) MCLK = 32.768 kHz 0.5 µA Operating temperature range T -40 +85 °C Conversion time tconv MCLK = 32.768 kHz 35 ms External clock signal (4) MCLK 30.000 32.768 35.000 kHz Duty cycle of MCLK 40/60 50/50 60/40 % Serial data clock SCLK 500 kHz NOTES 1) Under the assumption of one conversion every second. Conversion means either a pressure or a temperature measurement started by a command to the serial interface of MS5541C. 2) During conversion the sensor will be switched on and off in order to reduce power consumption; th e total on time within a conversion is about 2 ms. 3) This value can be reduced by switching off MCLK while MS5541C is in standby mode. 4) It is strongly recommended that a crystal oscillator be used because the device is sens itive to clock jitter. A square-wave form of the clock signal is a must. ANALOG DIGITAL CONVERTER (ADC) Parameter Symbol Conditions Min Typ Max Unit Resolution 16 Bit Linear Range 4'000 40'000 LSB Conversion Time MCLK = 32.768 kHz 35 ms INL Within linear range -5 +5 LSB
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 4 PERFORMANCE SPECIFICATIONS (CONTINUED) PRESSURE OUTPUT CHARACTERISTICS With the calibration data stored in the interface IC of the MS5541C, the following characteristics c an be achieved: (VDD = 3.0 V unless noted otherwise) Parameter Conditions Min Typ Max Unit Notes Resolution 1.2 mbar 1 Absolute Pressure Accuracy (Temperature range 0 .. +40 °C) p = 0 .. 5 bar p = 0 .. 10 bar p = 0 .. 14 bar -20 -40 -100 +20 +20 +20 mbar 2 Absolute Pressure Accuracy (Temperature range -40 .. +85 °C) p = 0 .. 5 bar p = 0 .. 10 bar p = 0 .. 14 bar -40 -60 -160 +100 +180 +200 mbar 3 Error over Temperature (p = const. relative to 20 °C) Ta = -40 .. +85 °C -10 +100 mbar Long-term Stability 6 months 20 mbar 4 Maximum Error over Supply Voltage VDD = 2.2 .. 3.6 V p = const. -16 16 mbar NOTES 1) A stable pressure reading of the given resolution requires taking the average of 2 to 4 subsequent pr essure values due to noise of the ADC. 2) Maximum error of pressure reading over the pressure range. 3) With the second-order temperature compensation as described in Section "FUNCTION". See nex t section for typical operating curves. 4) The long-term stability is measured with non-soldered devices. TEMPERATURE OUTPUT CHARACTERISTICS This temperature information is not required for most applications, but it is necessary to allow for temperature compensation of the pressure output. (VDD = 3.0 V unless noted otherwise) Parameter Conditions Min Typ Max Unit Notes Resolution 0.005 0.01 0.015 °C Accuracy T = 20 °C Maximum Error over Supply Voltage NOTES 1) With the second-order temperature compensation as described in Section "FUNCTION". See nex t section for typical operating curves. 2) At Ta = 25 °C.
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 5 PERFORMANCE SPECIFICATIONS (CONTINUED) DIGITAL INPUTS Parameter Symbol Conditions Min Typ Max Unit Input High Voltage VIH 80% VDD 100% VDD V Input Low Voltage VIL 0% VDD 20% VDD V Signal Rise Time tr 200 ns Signal Fall Time tf 200 ns DIGITAL OUTPUTS Parameter Symbol Conditions Min Typ Max Unit Output High Voltage VOH Isource = 0.6 mA 80% VDD 100% VDD V Output Low Voltage VOL Isink = 0.6 mA 0% VDD 20% VDD V Signal Rise Time tr 200 ns Signal Fall Time tf 200 ns
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 6 TYPICAL PERFORMANCE CURVES ADC-value D1 vs Pressure (typical) 10000 15000 20000 25000 30000 0 2000 4000 6000 8000 10000 12000 14000 Pressure (mbar) ADC-value D1 (LSB) -40°C 25°C 85°C ADC-value D2 vs Temperature (typical) 15000 20000 25000 30000 35000 40000 -40 -20 0 20 40 60 80 Temperature (°C) ADC-value D2 (LSB)
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 7 Absolute Pressure Accuracy after Calibration, 1st order compensation -100 -50 100 150 200 250 0 2000 4000 6000 8000 10000 12000 14000 Pressure (mbar) Pressure error (mbar) 85°C 60°C 25°C 0°C -40°C Absolute Pressure Accuracy after Calibration, 2nd order compensation -100 -80 -60 -40 -20 0 2000 4000 6000 8000 10000 12000 14000 Pressure (mbar) Pressure error (mbar) 85°C 60°C 25°C 0°C -40°C
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 8 Temperature Error Accuracy vs temperature (typical) -40 -20 0 20 40 60 80 Temperature (°C) Temperature error (°C) Temperature error (standard calculation) Temperature error (with 2nd order calculation) Pressure Error Accuracy vs temperature (typical) -50 -25 100 -40 -20 0 20 40 60 80 Temperature (°C) Pressure error (mbar) Pres. error 4bar (1st order) Pres. error 4bar (2nd order)
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 9 Pressure error vs supply voltage (typical) -10 Voltage (V) Pressure error (mbar) 14000 mbar 6000 mbar 1000 mbar Temperature error vs supply voltage (typical) -0.15 -0.1 -0.05 0.05 0.1 0.15 Voltage (V) Temperature error (°C)
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 10 FUNCTION GENERAL The MS5541C consists of a piezo-resistive sensor and a sensor interface IC. The main function of the MS5541C is to convert the uncompensated analogue output voltage from the piezo-resistive pr essure sensor to a 16-bit digital value, as well as providing a 16-bit digital value for the temperature of the sensor. Measured pressure (16-bit) “D1” Measured temperature (16-bit) “D2” As the output voltage of a pressure sensor is strongly dependent on temperature and process tolerances, it is necessary to compensate for these effects. This compensation procedure must be performed by software using an external microcontroller. For both pressure and temperature measurement the same ADC is used (sigma delta converter):
- for the pressure measurement, the differential output voltage from the pressure sensor is converted
- for the temperature measurement, the sensor bridge resistor is sensed and converted During both measurements the sensor will only be switched on for a very short tim e in order to reduce power consumption. As both, the bridge bias and the reference voltage for the ADC are derived from VDD, the digital output data is independent of the supply voltage. FACTORY CALIBRATION Every module is individually factory calibrated at two temperatures and t wo pressures. As a result, 6 coefficients necessary to compensate for process variations and temperature variations are calculated and stored in the 64-bit PROM of each module. These 64-bit (partitioned into four words of 16-bit) must be read by the microcontroller software and used in the program converting D1 and D2 into compensated pressure and temperature values. PRESSURE AND TEMPERATURE MEASUREMENT The sequence of reading pressure and temperature as well as of performing the software compensation is depicted in Fig. 3 and Fig. 5. First Word1 to Word4 have to be read through the serial interface. This can be done once after reset of the microcontroller that interfaces to the MS5541C. Next, the compensation coefficients C1 to C6 are extracted using bit-wise logical- and shift-operations (refer to Fig. 4 for the bit-pattern of Word1 to Word4). For the pressure measurement, the microcontroller has to read the 16-bit values for pressure (D1) and temperature (D2) via the serial interface in a loop (for instance every second). Then, the compe nsated pressure is calculated out of D1, D2 and C1 to C6 according to the algorithm in Fig. 3 (possibly using quadratic temperature compensation according to Fig. 5). All calculations can be performed with signed 16-bit vari ables. Results of multiplications may be up to 32-bit long (+sign). In the flow according to Fig. 3 a division follow s each multiplication. This division can be performed by bit-wise shifting (divisors are to the power of 2). It is ensured that the results of these divisions are less than 65536 (16 bit). For the timing of signals to read out Word1 to Word4, D1, and D2 please refer to the paragraph “Serial Interface". Sensor Word 1..4 Calculation in external micro- controller Pressure Temperature
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 11 System initialisation Pressure and temperature measurement Example: Word1, Word2, Word3 and Word4 (4x16 Bit) D1 = 17788 D2 = 26603 Start Convert calibration data into coefficients: (see bit pattern of Word1-Word4) Read calibration data (factory calibrated) from PROM of MS5541C Read digital pressure value from MS5541C D1 (16 Bit) Read digital temperature value from MS5541C Display pressure and temperature value Basic equations: Calculate calibration temperature UT1=8*C5+10000 Calculate temperature compensated pressure Difference between actual temperature and reference temperature: dT = D2 - UT1 Actual temperature: resolution) Calculate actual temperature D2 (16 Bit) SENST1 OFFT1 TCS TCO Tref TEMPSENS C1: Pressure sensitivity (13 Bit) C2: Pressure offset (13 Bit) C3: Temperature coefficient of pressure sensitivity (10 Bit) C4: Temperature coefficient of pressure offset (9 Bit) C5: Reference Temperature (12 Bit) C6: Temperature coefficient of the temperature (7 Bit) (Refer to application note AN518 for limits of coefficients and calculated results) Word1 = 18556 Word2 = 49183 Word3 = 22354 Word4 = 28083 C1 = 2319 C2 = 4864 C3 = 349 C4 = 219 C5 = 2002 C6 = 51 dT(D2) = D2 - Tref TEMP(D2)=20°+dT(D2)*TEMPSENS Offset at actual temperature: Sensitivity at actual temperature: Temperature compensated pressure in mbar: P = (SENS * (D1-OFF))/212 + 1000 OFF(D2)=OFFT1+TCO*dT(D2) SENS(D2)=SENST1+TCS*dT(D2) P(D1,D2)=D1*SENS(D2)-OFF(D2) dT = 587 TEMP = 243 = 24.3 °C OFF = 14859 SENS = 4198 P = 4001 = 4001 mbar UT1 = 26016 Fig. 3: Flow chart for pressure and temperature reading and software compensation
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 12 NOTES 1) Readings of D2 can be done less frequently, but the display w ill be less stable in this case. 2) For a stable display of 1 mbar resolution, it is recommended to display the average of 8 s ubsequent pressure values. C1 (13 Bit) C2/I (3 Bit) Word 1 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 DB12 DB11 DB10 C2/II (10 Bit) C5/I (6 Bit) Word 2 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 DB11 DB10 DB9 DB8 DB7 DB6 C3 (10 Bit) C5/II (6 Bit) Word 3 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 DB5 DB4 DB3 DB2 DB1 DB0 C4 (9 Bit) C6 (7 Bit) Word 4 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB1 DB6 DB5 DB4 DB3 DB2 DB1 DB0 Fig. 4: Arrangement (Bit-pattern) of calibration data in Word1 to Word4
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 13 SECOND-ORDER TEMPERATURE COMPENSATION In order to obtain full temperature accuracy over the whole temperature range, it is recomm ended to compensate for the non-linearity of the output of the temperature sensor. This can be achie ved by correcting the calculated temperature and pressure by a second order correction factor. The second-order factors are calculated as follows : Fig. 5: Flow chart for calculating the temperature and pressure to the optimum accuracy. High Temperatures dT2 = dT – (dT/128*dT/128)/8 dT < 0 yes Calculate temperature Low Temperatures dT2 = dT – (dT/128*dT/128)/2 dT 0 yes
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 14 SERIAL INTERFACE The MS5541C communicates with microprocessors and other digital systems via a 3-wire synchronous serial interface as shown in Fig. 1. The SCLK (Serial clock) signal initiates the communication and synchronizes the data transfer with each bit being sampled by the MS5541C on the rising edge of S CLK and each bit being sent by the MS5541C on the rising edge of SCLK. The data should thus be sampled by the microcontroll er on the falling edge of SCLK and sent to the MS5541C with the falling edge of SCLK. The SCLK-signal is generated by the microprocessor’s system. The digital data provided by the MS5541C on the DOUT pin is either the conversion result or the software calibration data. In addition, the signal DOUT (Data out) is also us ed to indicate the conversion status (conversion-ready signal, see below). The selection of the output data is done by sending the corresponding instruction on the pin DIN (Data input). Following is a list of possible output data instructions: Conversion start for pressure measurement and ADC- data-out “D1” (Figure 6a) Conversion start for temperature measurement and ADC- data-out “D2” (Figure 6b) Calibration data read-out sequence for Word1 (Figure 6c) Calibration data read-out sequence for Word2 (Figure 6d) Calibration data read-out sequence for Word3 (Figure 6c) Calibration data read-out sequence for Word4 (Figure 6d) RESET sequence (Figure 6e) Every communication starts with an instruction sequence at pin DIN. Fig. 6 shows the timing diagrams for the MS5541C. The device does not need a ‘Chip select’ signal. Instead there is a START sequence (3-Bit high) before each SETUP sequence and STOP sequence (3-Bit low) after each SETUP s equence. The SETUP sequence consists in 4-Bit that select a reading of pressure, temperature or calibration data. In c ase of pressure- (D1) or temperature- (D2) reading the module acknowledges the start of a conversion by a l ow to high transition at pin DOUT. Two additional clocks at SCLK are required after the acknowledge signal. Then S CLK is to be held low by the microcontroller until a high to low transition on DOUT indicates the end of the conversion. This signal can be used to create an interrupt in the microcontroller. The mic rocontroller may now read out the 16 bit word by giving another 17 clocks on the SLCK pin. It is possible to interrup t the data READOUT sequence with a hold of the SCLK signal. It is important to always read out the last conversion result before starting a new conversion. The RESET sequence is special as the module in any state recognizes its unique pattern. By consequence, it can be used to restart if synchronization between the microcontroller and the MS5541C has been lost. This sequence is 21-bit long. The DOUT signal might change during that sequence (see Fig. 6e) . It is recommended to send the RESET sequence before each CONVERSION sequence to avoid hanging up the protocol perm anently in case of electrical interference. sequence: START+P-measurement SCLKDOUTDIN Bit7 Conversion start for pressure measurement and ADC-data-out "D1": end of conversion Bit6Bit5Bit4Bit3Bit2Bit1Bit0 conversion (33ms) DB7 ADC-data out MSB ADC-data out LSB Bit8 Bit9 Start-bit Stop-bit DB6 DB5 DB4 DB3 DB2 DB1 DB0 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 start of conversion Setup-bits Fig. 6a: D1 ACQUISITION sequence
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 15 sequence: START+T-measurement SCLKDOUTDIN Bit7 Conversion start for temperature measurement and ADC-data-out "D2": end of conversion Bit6Bit5Bit4Bit3Bit2Bit1Bit0 conversion (33ms) Bit8 Bit9 Start-bit Stop-bitSetup-bits start of conversion DB7 ADC-data out MSB ADC-data out LSB DB6 DB5 DB4 DB3 DB2 DB1 DB0 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 Fig. 6b: D2 ACQUISITION sequence sequence: coefficient read + address SCLKDOUTDIN Bit7 Calibration data read out sequence for word 1/ word 3: Bit6Bit5Bit4Bit3Bit2Bit1Bit0 DB7 coefficient-data out MSB coefficient-data out LSB Bit8 Bit9 Start-bit Stop-bit DB6 DB5 DB4 DB3 DB2 DB1 DB0 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 Bit10Bit11 address word 1 address word 3 Setup-bits Fig. 6c: Word1, Word3 READING sequence address word 2 address word 4 sequence: coefficient read + address SCLKDOUTDIN Bit7 Calibration data read out sequence for word 2/ word 4: Bit6Bit5Bit4Bit3Bit2Bit1Bit0 DB7 coefficient-data out MSB coefficient-data out LSB Bit8 Bit9 Start-bit Stop-bit DB6 DB5 DB4 DB3 DB2 DB1 DB0 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 Bit10Bit11 Setup-bits Fig. 6d: W2, W4 READING sequence sequence: RESET SCLKDOUTDIN Bit7 RE SE T - sequence: Bit6Bit5Bit4Bit3Bit2Bit1Bit0 Bit8 Bit9Bit10Bit11 Bit12Bit13Bit14Bit15Bit16Bit17Bit18Bit19Bit20 Fig. 6e: RESET sequence (21 bit)
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 16
APPLICATION INFORMATION
The advantage for this combination of a sensor with a directly adapted integrated c ircuit is to save other external components and to achieve very low power consumption. The main application field for this system includes portable devices with battery supply, but its high accuracy and resolution make it also suited for industrial and automotive applications. The possibility to compensate the sensor with software allo ws the user to adapt it to his particular application. Communication between the MS5541C and the widely avai lable microcontrollers is realised over an easy- to-use 3-wire serial interface. Customers may select which microcontroller sy stem to be used, and there are no specific standard interface cells required, which may be of interest for specially designed 4 Bit- microcontroller applications. CALIBRATION The MS5541C is factory calibrated. The calibration data is stored inside the 64 bit PROM memor y. SOLDERING Please refer to the application note AN808 for all soldering issues. HUMIDITY, WATER PROTECTION The silicon pressure transducer and the bonding wires are protected by an anticorrosive and antimagnetic protection cap. The MS5541C carries a metal protection cap filled with silicone gel for enhanced protection against humidity. The properties of this gel ensure function of the sensor even when in direct water contact. This feature can be useful for waterproof watches or other applications, where direct water contact cannot be avoided. Nevert heless the user should avoid drying of hard materials like for example salt particles on t he silicone gel surface. In this case it is better to rinse with clean water afterwards. Special care has to be taken to not mechani cally damage the gel. Damaged gel could lead to air entrapment and consequently to unstable sensor signal, especiall y if the damage is close to the sensor surface. The metal protection cap is fabricated of special anticorrosive and antimagnetic stainless steel in order to avoid any corrosive battery effects inside the final product. The MS5541C was qualified referring to the ISO 6425 standard and can withstand a pressure of 30 bar in salt water. The concentration of the see water used for the qualification is 41 g of see salt for 1 litre of DI water. For underwater operations like specified in ISO 6425 standard it is importan t to seal the sensor with a rubber O- Ring around the metal Ring. Any salt water coming to the contact side (ceramic and Pads) of the sensor could lead to permanent damage. For "water-resistant" watches it is recommended to provide a stable mechanical pusher from the backside of the sensor. Otherwise the overpressure might push the sensor backwards and even bend the electronic board on which the sensor is mounted. LIGHT SENSITIVITY The MS5541C 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. As the effect is reversible there will be no damage, but the user h as to take care that in the final product the sensor cannot be exposed to direct light during operation. This can be achi eved for instance by placing mechanical parts with holes in such that light cannot pass.
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 17 CONNECTION TO PCB The package outline of the module allows the use of a flexible PCB to connec t it. This can be important for applications in watches and other special devices, and will also reduce mechanical stress on the device. For applications subjected to mechanical shock, it is recommended to enhance the mec hanical reliability of the solder junctions by covering the rim or the corners of MS5541C's ceramic substrate with glue or Globtop-like material. DECOUPLING CAPACITOR Particular care must be taken when connecting the device to power supply. A 47 F tantalum capacitor must be placed as close as possible of the MS5541C's VDD pin. This capacitor will stabili ze the power supply during data conversion and thus, provide the highest possible accuracy. APPLICATION EXAMPLE: DIVING COMPUTER SYSTEM USING MS5541C MS5541C is a circuit that can be used in connection with a microcontrol ler in diving computer applications. It is designed for low-voltage systems with a supply voltage of 3V, particularly i n battery applications. The MS5541C is optimised for low current consumption as the AD-converter clock (MCLK) can use the 32.768 kHz frequency of a standard watch crystal, which is supplied in most portable watch systems. For applications in altimeter systems MEAS Switzerland can deliver a simple formula to calculate the altitude, based on a linear interpolation, where the number of interpolation points influences the accuracy of the f ormula. 4/8bit-Microcontroller LCD-Display EEPROM Keypad MS5541C SCLK DIN DOUT MCLK XTAL1 XTAL2 32.768 kHz optional VDD GND VDD GND 3V-Battery 47µF Tantal Figure 7: Demonstration of MS5541C in a diving computer
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 18 PIN CONFIGURATION Fig. 2: Pin configuration of MS5541C Pin Name Pin Type Function SCLK 1 I Serial data clock GND 2 G Ground PV (1) 3 N Negative programming voltage PEN (1) 4 I Programming enable VDD 5 P Positive supply voltage MCLK 6 I Master clock (32.768 kHz) DIN 7 I Serial data input DOUT 8 O Serial data output NOTE 1) Pin 3 (PV) and Pin 4 (PEN) are only used by the manufacturer for calibration purpo ses and should not be connected. RECOMMENDED PAD LAYOUT Pad layout for bottom side of MS5541C soldered onto printed circuit board.
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 19 DEVICE PACKAGE OUTLINES Fig. 8: Device package outlines of MS5541-C
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 20 ASSEMBLY MECHANICAL STRESS It is recommended to avoid mechanical stress on the PCB on which the sensor i s mounted. The thickness of the PCB should not be below 1.6 mm. A thicker PCB is stiffer creating less s tress on the soldering contacts. For applications where mechanical stress cannot be avoided (for example ultrasound welding of the case or thin PCB’s in watches) please fix the sensor with drops of low stress epoxy (for example Hysol FP-440 1). MOUNTING The MS5541C can be placed with automatic Pick&Place equipment using vacuum nozzles . It will not be damaged by the vacuum. Due to the low stress assembly the sensor does not show pressure hysteresis effects. Special care has to be taken to not touch the protective gel of the sensor during the assembly. The MS5541C can be mounted with the cap down or the cap looking upwards. In both cases it is important to solder all contact pads. The Pins PEN and PV shall be left open or connected to VDD. Do not connect the Pins PEN and PV to GND! SEALING WITH O-RING In products like outdoor watches the electronics must be protected against direct water or humidity. For those products the MS5541-CM provides the possibility to seal with an O-ring. The protective cap of the MS5541CM is made of special anticorrosive stainless steel with a polished surface. In addition to this the MS5541CM 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 di rection. CLEANING The MS5541C has been manufactured under cleanroom conditions. Each device has b een inspected for the homogeneity and the cleanness of the silicone gel. It is therefore recommended to assemble the sensor under class 10’000 or better conditions. Should this not be possible, it is recommended to protect the sensor opening during assembly from entering particles and dust. To avoid cleaning of the PCB, solde r paste of type “no -clean” shall be used. Cleaning might damage the sensor! ESD PRECAUTIONS The electrical contact pads are protected against ESD up to 4 kV HBM (human body model). It is therefore essential to ground machines and personal properly during assembly and handling of the d evice. The MS5541C is shipped in antistatic transport boxes. Any test adapters or production transport boxes used during the assembly of the sensor shall be of an equivalent antistatic material.
SENSOR SOLUTIONS ///MS5541C 09/2015 Page 21
ORDERING INFORMATION
Part Number / Art. Number Product Delivery Form 325541009-00 MS5541C Miniature 14 bar Module White gel Tube 325541009-50 MS5541C Miniature 14 bar Module White gel T&R Tape& reel TOP-UP 325541008-00 MS5541C Miniature 14 bar Module Transparent gel Tube 325541008-50 MS5541C Miniature 14 bar Module Transparent gel T&R Tape& reel TOP-UP 325541021-00 MS5541C Miniature 14 bar Module Transparent gel HE Tube 325541021-50 MS5541C Miniature 14 bar Module Transparent gel HE T&R Tape& reel TOP-UP TE.com/sensorsolutions Measurement Specialties, Inc., a TE Connectivity company. Measurement Specialties, TE Connectivity, TE Connectivity (logo) and EVERY CONNECTION COUNTS are trademarks. All other logos, products and/or company names referred to herein might be trademarks of their respective owners. The information given herein, including drawings, illustrations and schematics which are intended for illustration purposes only, is believe d to be reliable. However, TE Connectivity makes no warranties as to its accuracy or completeness and disclaims any liability in connection with its use. TE Connectivity‘s obligations shall only be as set forth in TE Connectivity‘s Standard Terms and Conditions of Sale for this product and in no case will TE Connectivity be liable for any incidental, indirect or consequential damages arising out of the sale, resale, use or misuse of the product. Users of TE Connectivity products should make their own evaluation to determine the suitability of each such product for the specific application. © 2015 TE Connectivity Ltd. family of companies All Rights Reserved. DA5541C_009 0005541C1194 ECN2178 NORTH AMERICA Measurement Specialties, Inc., a TE Connectivity Company
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