View MS5541-30C_4847105.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

MS5541-30C (RoHS*) MINIATURE 30 bar MODULE
* * * * * * * * * DESCRIPTION
The MS5541-30C is the high-pressure 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. The ESD sensitivity has been improved to 4kV on all pins. In addition to this the MS554130C 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.
0 - 30 bar absolute pressure range 6 coefficients for a software compensation stored on-chip Piezoresistive silicon micromachined sensor Integrated pressure sensor 6.2x6.4 mm 16 Bit ADC 3-wire serial interface 1 system clock line (32.768 kHz) Low voltage and low power consumption RoHS-compatible & Pb-free*
FEATURES
* * * * * * Resolution 3.0 mbar Supply voltage 2.2 V to 3.6 V Operating current < 5uA Standby current < 0.1uA -40 to +85 C C No external components required
APPLICATIONS
* * Diving computers and divers watches Mobile water depth measurement systems
BLOCK DIAGRAM
VDD MCLK Input MUX SENSOR +IN dig. Filter Digital Interface ADC DIN DOUT SCLK
-IN
Sensor Interface IC
SGND
Memory (PROM) 64 bits
GND
Fig.: 1 Block Diagram MS5541-30C
*
The European RoHS directive 2002/95/EC (Restriction of the use of certain Hazardous Substances in electrical and electronic equipment) bans the use of lead, mercury, cadmium, hexavalent chromium and polybrominated biphenyls (PBB) or polybrominated diphenyl ethers (PBDE).
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
1
PIN CONFIGURATION
Fig. 2: Pin configuration of MS5541-30C Pin Name SCLK VSS PV (1) PEN (1) VDD MCLK DIN DOUT Pin 1 2 3 4 5 6 7 8 Type I G N I P I I O Function Serial data clock Ground Negative programming voltage (do not connect) Programming enable (do not connect) Positive supply voltage Master clock (32.768kHz) Serial data input Serial data output
NOTE 1) Pins 3 (PV) and 4 (PEN) are only used by the manufacturer for calibration purposes and should not be connected.
ABSOLUTE MAXIMUM RATINGS
Parameter Supply Voltage Storage Temperature Overpressure Symbol VDD TS P Conditions Ta = 25 C Ta = 25 C
o o
Min -0.3 -40
Max 4 +85 50
Unit V C bar
o
Notes 1
NOTES 1) Storage and operation in an environment of dry and non-corrosive gases.
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
2
RECOMMENDED OPERATING CONDITIONS
Parameter Operating pressure range Supply voltage Supply current, Average (1) during conversion (2) standby (no conversion) Current consumption into MCLK (3) Operating temperature Range Conversion time (16 Bit) External clock signal (4) Duty cycle of MCLK Serial data clock SCLK Symbol p VDD VDD = 3.0 V Iavg ISC Iss MCLK=32768Hz Ta Tconv MCLK MCLK=32768Hz 30000 40/60 32768 50/50 -40 +25 4 1 0.1 0.5 +85 35 35000 60/40 500 A mA A A C ms Hz % kHz Conditions (T=25 VDD=3.0V unless noted otherwise) C, Min Typ Max Unit 0 30 bar 2.2 3.0 3.6 V
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 MS5541-30C. 2) 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 2ms. 3) This value can be reduced by switching off MCLK while MS5541-30C is in standby mode. 4) It is 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.
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
3
ELECTRICAL CHARACTERISTICS
DIGITAL INPUTS (T = -40 .. 85 VDD = 2.2 V .. 3.6 V) C C, Typ Max Unit 100% VDD 20% VDD 200 200 V V ns ns
Parameter Input High Voltage Input Low Voltage Signal Rise Time Signal Fall Time
Symbol VIH VIL tR tf
Conditions
Min
80% VDD 0% VDD
DIGITAL OUTPUTS (T=-40 .. 85 VDD = 2.2V..3.6V) C C, Typ Max Unit 100% VDD 20% VDD 200 200 V V ns ns
Parameter Output High Voltage Output Low Voltage Signal Rise Time Signal Fall Time
Symbol VOH VOL tr tf
Conditions ISource = 0.6 mA ISink = 0.6 mA
Min 80% VDD 0% VDD
AD-CONVERTER (T=25 VDD =3.0V) C, Max Unit Bit 40000 35 -5 5 LSB ms LSB
Parameter Resolution Linear Range Conversion Time INL
Symbol
Conditions
Min
Typ 16
4000 MCLK=32768Hz within linear Range
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
4
PRESSURE OUTPUT CHARACTERISTICS
With the calibration data stored in the interface IC of the MS5541-30C the following characteristics can be achieved: (VDD = 3.0 V unless noted otherwise) Parameter Resolution Absolute Pressure Accuracy (Temperature range 0 .. +40 C) Absolute Pressure Accuracy (Temperature range -40 .. +85 C) Error over Temperature (p = const. relative to 20 C) Long-term Stability Maximum Error over Supply Voltage p= p= p= p= p= p= 0 .. 10bar 0 .. 20bar 0 .. 30bar 0 .. 10bar 0 .. 20bar 0 .. 30bar -50 -100 -250 -100 -150 -400 -25 50 -40 +40 Conditions Min Typ 3.0 +50 +50 +50 +250 +450 +500 +250 Max Unit mbar mbar mbar mbar mbar mbar mbar mbar mbar mbar 4 Note 1 2
3
Ta = -40...+85 C 6 months VDD = 2.2...3.6V
NOTES 1) A stable pressure reading of the given resolution requires taking the average of 2 to 4 subsequent pressure 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 next 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. The reference temperature is 20 C. Parameter Resolution Accuracy Maximum Error over Supply Voltage Ta = 20 C Ta = -40...+85 C VDD = 2.2...3.6V Conditions Min 0.005 -0.8 -2 -0.2 Typ Max 0.015 0.8 +6 0.2 Unit C C C C 1 Note
NOTE 1) With the second-order temperature compensation as described in Section "FUNCTION". See next section for typical operating curves.
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
5
TYPICAL PERFORMANCE CURVES
ADC-value D1 vs Pressure (typical)
30000
25000
ADC-value D1 (LSB)
20000
-40 C 25 C 85 C
15000
10000 0 5000 10000 15000 Pressure (mbar) 20000 25000 30000
ADC-value D2 vs Temperature (typical)
40000
35000
ADC-value D2 (LSB)
30000
25000
20000
15000 -40 -20 0 20
Temperature (C)
40
60
80
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
6
Absolute Pressure Accuracy after Calibration, 1st order compensation
600
500
400
Pressure error (mbar)
300 85 C 200 60 C 25 C 0 C -40 C 100
0 0 -100 5000 10000 15000 20000 25000 30000
-200 Pressure (mbar)
Absolute Pressure Accuracy after Calibration, 2nd order compensation
200
150
100
Pressure error (mbar)
50 85 C 60 C 0 0 -50 5000 10000 15000 20000 25000 30000 25 C 0 C -40 C
-100
-150
-200 Pressure (mbar)
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
7
Temperature Error Accuracy vs temperature (typical)
15
10
Temperature error ( C)
Temperature error (standard calculation)
5
Temperature error (with 2nd order calculation)
0 -40 -20 0 20 40 60 80
-5 Temperature ( C)
Pressure Error Accuracy vs temperature (typical)
250
200
150 Pressure error (mbar)
Pres. error 10bar (1st order)
100
Pres. error 10bar (2nd order)
50
0 -40 -20 0 20 40 60 80
-50 Temperature ( C)
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
8
Pressure error vs supply voltage (typical)
25
20
15
10
Pressure error (mbar)
5
30000 mbar 15000 mbar
2.2 2.4 2.6 2.8 3 3.2 3.4 3.6
0
-5
2500 mbar
-10
-15
-20
-25 Voltage (V)
Temperature error vs supply voltage (typical)
0.15
0.1
0.05 Temperature error ( C)
0 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6
-0.05
-0.1
-0.15 Voltage (V)
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
9
FUNCTION
GENERAL The MS5541-30C consists of a piezoresistive sensor and a sensor interface IC. The main function of the MS5541-30C is to convert the uncompensated analog output voltage from the piezoresistive pressure sensor into a 16-Bit digital value, as well as providing a 16-Bit digital value for the temperature of the sensor. * measured pressure (16-Bit) * measured temperature (16-Bit) "D1" "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.
D1 D2 Word1..4 Pressure
Sensor
Calculation in external microcontroller
Temperature
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 time 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 two pressures. As a result, 6 coefficients necessary to compensate for process variations and temperature variations are calculated and stored in the 64Bit 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 flow chart, Fig. 3 and Fig. 5. First the 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 MS5541-30C. 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 word 1 to word 4). 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 compensated 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 variables. Results of multiplications may be up to 32-Bit long (+sign). In the flow according to Fig. 3 each multiplication is followed by a division. 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".
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
10
Start System initialisation Read calibration data (factory calibrated) from PROM of MS5541-30
Word1, Word2, Word3 and Word4 (4x16 Bit)
Basic equations:
Example:
Word1 = 46076 Word2 = 14170 Word3 = 39937 Word4 = 33721
Convert calibration data into coefficients: (see bit pattern of Word1-Word4)
C1: Pressure sensitivity C2: Pressure offset C3: Temperature coefficient of pressure sensitivity C4: Temperature coefficient of pressure offset C5: Reference Temperature C6: Temperature coefficient of the temperature (13 Bit) (13 Bit) (10 Bit) (9 Bit) (12 Bit) (7 Bit) SENST1 OFFT1 TCS TCO Tref TEMPSENS
C1 = 5759 C2 = 4317 C3 = 624 C4 = 263 C5 = 1665 C6 = 57
Pressure and temperature measurement
Read digital pressure value from MS5541-30 D1 (16 Bit)
D1 = 15380
Read digital temperature value from MS5541-30 D2 (16 Bit)
D2 = 22027 UT1 = 23320
Calculate calibration temperature
UT1=8*C5+10000
Calculate actual temperature
Difference between actual temperature and reference temperature:
dT(D2) = D2 - Tref TEMP(D2)=20+dT(D2)*TEMPSENS
dT
= -1293
dT = D2 - UT1
Actual temperature:
TEMP = 200 + dT*(C6+100)/2 (0.1C)
11
TEMP = 101 C = 10.1
Calculate temperature compensated pressure
Offset at actual temperature:
OFF(D2)=OFFT1+TCO*dT(D2) SENS(D2)=SENST1+TCS*dT(D2)
OFF = C2 + ((C4-250)*dT)/212 + 10000
Sensitivity at actual temperature:
OFF
= 14312
SENS = C1/2 + ((C3+200)*dT)/213 + 3000
SENS = 5749
Temperature compensated pressure in mbar:
P = (SENS * (D1-OFF))/211 + 1000
P(D1,D2)=D1*SENS(D2)-OFF(D2)
P
= 3998 = 3998 mbar
Display pressure and temperature value
Fig. 3: Flow chart for pressure/temperature reading and software compensation. NOTES 1) Readings of D2 can be done less frequently, but the display will be less stable in this case 2) For a stable display of 1 mbar resolution, it is recommended to display the average of 4 to 8 subsequent pressure values.
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
11
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)
Word 2
DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 DB11 DB10
C5/I (6 Bit)
DB9 DB8 DB7 DB6
C3 (10 Bit)
Word 3
DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 DB5 DB4
C5/II (6 Bit)
DB3 DB2 DB1 DB0
C4 (9 Bit)
Word 4
DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB1 DB6 DB5 DB4
C6 (7-Bit)
DB3 DB2 DB1 DB0
Fig. 4: Arrangement (Bit-pattern) of calibration data in Word1 to Word4. SECOND-ORDER TEMPERATURE COMPENSATION In order to obtain full temperature accuracy over the whole temperature range, it is 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:
dT < 0
dT 0
yes
yes
Low Temperatures
dT2 = dT - (dT/128*dT/128)/2
High Temperatures
dT2 = dT - (dT/128*dT/128)/8
Calculate temperature
TEMP = (200 + dT2*(C6+100)/2 ) (0.1 C)
11
Fig. 5: Flow chart for calculating the temperature and pressure to the optimum accuracy.
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
12
SERIAL INTERFACE The MS5541-30C 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 MS5541-30C on the rising edge of SCLK and each Bit being sent by the MS5541-30C 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 MS5541-30C with the falling edge of SCLK. The SCLK-signal is generated by the microprocessor's system. The digital data provided by the MS5541-30C on the DOUT pin is either the conversion result or the software calibration data. In addition the signal DOUT (Data Out) is also used 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 Conversion start for temperature measurement and ADC-data-out Calibration data read-out sequence for word 1 Calibration data read-out sequence for word 2 Calibration data read-out sequence for word 3 Calibration data read-out sequence for word 4 RESET sequence "D1" "D2" (Figure 6a) (Figure 6b) (Figure 6c) (Figure 6d) (Figure 6c) (Figure 6d) (Figure 6e)
Every communication starts with an instruction sequence at pin DIN. Fig. 6 shows the timing diagrams for the MS5541-30C. 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 Sequence. The Setup Sequence consists in 4-Bit that select a reading of pressure, temperature or calibration data. In case of pressure- (D1) or temperature- (D2) reading the module acknowledges the start of a conversion by a low to high transition at pin DOUT. Two additional clocks at SCLK are required after the acknowledge signal. Then SCLK 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 microcontroller may now read out the 16-Bit word by giving another 17 clocks on the SLCK pin. It is possible to interrupt the data read-out 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 its unique pattern is recognized by the module in any state. By consequence it can be used to restart if synchronization between the microcontroller and the MS5541-30C 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 first CONVERSION sequence to avoid hanging up the protocol permanently in case of electrical interference.
DOUT SCLK
Conversion start for pressure measurement and ADC-data-out "D1":
end of conversion
start of conversion
conversion (33ms)
ADC-data out MSB DB7 DB6 DB5 DB4 DB3 DB2 DB1
ADC-data out LSB DB0 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
DIN
sequence: START+P-measurement Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Bit8 Bit9 Start-bit Setup-bits Stop-bit
Fig. 6a: D1 acquisition sequence
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
13
DOUT SCLK
Conversion start for temperature measurement and ADC-data-out "D2":
end of conversion
start of conversion
conversion (33ms)
ADC-data out MSB DB7 DB6 DB5 DB4 DB3 DB2 DB1
ADC-data out LSB DB0 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
DIN
sequence: START+T-measurement Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Bit8 Bit9 Start-bit Setup-bits Stop-bit
Fig. 6b: D2 acquisition sequence
DOUT SCLK Calibration data read out sequence for word 1/ word 3:
coefficient-data out MSB DB7 DB6 DB5 DB4 DB3 DB2 DB1 sequence: coefficient read + address Bit0 Bit1 Bit2 Start-bit Bit3 Bit4 Bit5 Bit6 Bit7 Bit8 Bit9 Bit10 Bit11 Setup-bits Stop-bit address word 1
coefficient-data out LSB DB0 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
DIN
address word 3
Fig. 6c: W1, W3 reading sequence
DOUT SCLK Calibration data read out sequence for word 2/ word 4:
coefficient-data out MSB DB7 DB6 DB5 DB4 DB3 DB2 DB1 sequence: coefficient read + address Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Bit8 Bit9 Bit10 Bit11 Start-bit Setup-bits Stop-bit address word 2
coefficient-data out LSB DB0 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
DIN
address word 4
Fig. 6d: W2, W4 reading sequence
DOUT SCLK RESET - sequence:
DIN
sequence: RESET Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Bit8 Bit9 Bit10 Bit11Bit12 Bit13 Bit14 Bit15
Fig. 6e: Reset sequence (21-Bit)
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
14
APPLICATION INFORMATION
GENERAL The advantage for this combination of a sensor with a directly adapted integrated circuit 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 allows the user to adapt it to his particular application. Communication between the MS5541-30C and the widely available microcontrollers is realised over an easy-to-use 3-wire serial interface. Customers may select which microcontroller system 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 MS5541-30C is factory calibrated. The calibration data is stored inside the 64 Bit PROM memory. 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 MS5541-30C 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. Nevertheless the user should avoid drying of hard materials like for example salt particles on the silicone gel surface. In this case it is better to rinse with clean water afterwards. Special care has to be taken to not mechanically damage the gel. Damaged gel could lead to air entrapment and consequently to unstable sensor signal, especially 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. For underwater operations it is important 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. LIGHT SENSITIVITY The standard version of MS5541-30C 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 has to take care that in the final product the sensor cannot be exposed to direct light during operation. This can be achieved for instance by placing mechanical parts with holes in such that light cannot pass. CONNECTION TO PCB For "under water" devices it is necessary 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. For applications subjected to mechanical shock, it is recommended to enhance the mechanical reliability of the solder junctions by covering the rim or the corners of MS5541-30C's ceramic substrate with glue or Globtop like material. DECOUPLING CAPACITOR Particular care must be taken when connecting the device to power supply: A 47F tantalum capacitor must be placed as close as possible of the MS5541-30C's VDD pin. This capacitor will stabilize the power supply during data conversion and thus, provide the highest possible accuracy. DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
15
APPLICATION EXAMPLE: DIVING COMPUTER SYSTEM USING MS5541-30C MS5541-30C is a circuit that can be used in connection with a microcontroller in diving computer applications. It is designed for low-voltage systems with a supply voltage of 3V, particularly in battery applications. The MS554130C 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.
3V-Battery
LCD-Display
VDD XTAL1 32.768 kHz
MS5541-30
VDD MCLK DIN DOUT SCLK GND GND 47F Tantal XTAL2
Keypad 4/8bit-Microcontroller
EEPROM
optional
Fig. 7: Demonstration of MS5541-30C in a diving computer
RECOMMENDED PAD LAYOUT
Pad layout for bottom side of MS5541-30C soldered onto printed circuit board
Fig. 8: Pad layout of MS5541-30C
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
16
DEVICE PACKAGE OUTLINES
Fig. 9: Device package outlines of MS5541-30C
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
17
ASSEMBLY
MECHANICAL STRESS It is recommended to avoid mechanical stress on the PCB on which the sensor is mounted. The PCB thickness should be sufficient and does not flex with the increase pressure. To increase the rigidity it is necessary to provide a stable mechanical pusher from the backside of the sensor. For applications where mechanical stress cannot be avoided (for example ultrasound welding of the case or thin PCB's in diving computer) please fix the sensor with drops of low stress epoxy (for example Hysol FP-4401).
MOUNTING The MS5541-30C 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. 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 diving computers the electronics must be protected against direct water or humidity. For those products the MS5541-30C provides the possibility to seal with an O-ring. The protective cap of the MS5541-30C is made of special anticorrosive stainless steel with a polished surface. In addition to this the MS5541-30C 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.
CLEANING The MS5541-30C has been manufactured under cleanroom conditions. Each device has been 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, solder paste of type "no-clean" shall be used. Cleaning might damage the sensor!
ESD PRECAUTIONS The electrical contact pads are protected against ESD according to 4 kV HBM (human body model). It is therefore essential to ground machines and personal properly during assembly and handling of the device. The MS5541-30C 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.
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
18
ORDERING INFORMATION
Product Code MS5541-30CM
Product Miniature 30 bar module
Art.-Nr.
Package SMD hybrid with solder paste, anticorrosive and antimagnetic metal protection cap, white silicon gel sensor protection
Comments
325541010
standard version
FACTORY CONTACTS
Intersema Sensoric SA Ch. Chapons-des-Pres 11 CH-2022 BEVAIX SWITZERLAND Tel. (032) 847 9550 Tel. Int. +41 32 847 9550 Telefax +41 32 847 9569 e-mail: http://www.intersema.ch
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. Applications for any devices shown in this data sheet are for illustration only and Intersema makes no claim or warranty that such applications will be suitable for the use specified without further testing or modification.
DA5541-30C_001.doc
0005541C1348 ECN1143
Sept. 25th, 2008
19

▲Up To Search▲

Price & Availability of MS5541-30C

	To Download MS5541-30C Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .