MS8607-02BA01
PHT Combination Sensor
SPECIFICATIONS
Integrated pressure, humidity and temperature sensor
QFN package 5 x 3 x 1 mm3
Operating range: 10 to 2000 mbar, 0%RH to 100%RH,
-40 to 85 °C
High-resolution module: 0.016 mbar, 0.04%RH, 0.01°C
Supply voltage: 1.5 to 3.6 V
Fully factory calibrated sensor
I2C interface
The MS8607 is the novel digital combination sensor of MEAS
providing 3 environmental physical measurements all-in-one:
pressure, humidity and temperature (PHT). This product is
optimal for applications in which key requirements such as ultra
low power consumption, high PHT accuracy and compactness
are critical. High pressure resolution combined with high PHT
linearity makes the MS8607 an ideal candidate for environmental
monitoring and altimeter in smart phones and tablet PC, as well
as PHT applications such as HVAC and weather stations. This
new sensor module generation is based on leading MEMS
technologies and latest benefits from Measurement Specialties
proven experience and know-how in high volume manufacturing
of sensor modules, which has been widely used for over a
decade.
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PHT Combination Sensor
FEATURES
FIELD OF APPLICATION
Smart phones and Tablet PCs
HVAC applications
Weather station
Printers
Home Appliance and humidifiers
TECHNICAL DATA
Sensor Performances (VDD = 3 V)
Characteristics
Pressure [mbar]
Min
Max. Operating Range
Absolute Accuracy @25°C
Typ
10
Relative Humidity [%RH]
Max
Min
2000
0
300…1100mbar
-2
Resolution (highest mode)
SENSOR SOLUTIONS ///MS8607-02BA01
Max
Min
100
-40
20…80%RH
2
0.016
Typ
Temperature [°C]
-3
09/2015
Max
+85
@ 25°C
3
0.04
Typ
-1
1
0.01
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PHT Combination Sensor
PERFORMANCE SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Parameter
Supply voltage
Symbol
VDD
Storage temperature
Overpressure
Maximum Soldering
Temperature
ESD rating
Latch up
Condition
Min.
-0.3
-20
TS
Pmax
Typ.
Max.
3.6
Unit
V
85
°C
bar
250
°C
2
100
kV
mA
Max.
3.6
+85
Unit
V
°C
nF
6
Tmax
40 sec max
-2
Human Body Model
JEDEC standard No 78
-100
ELECTRICAL CHARACTERISTICS
Parameter
Operating Supply voltage
Operating Temperature
VDD to GND Capacitor
Supply current P or T
(1 Pressure or temperature
conversion per sec.)
Symbol
VDD
T
General electrical characteristics
Condition
Min.
Typ.
1.5
3.0
-40
+25
220
470
IPT
OSR 8192
4096
2048
1024
512
256
IH
OSR 8192
4096
2048
1024
20.09
10.05
5.02
2.51
1.26
0.63
µA
6.22
Supply current H
(1 humidity conversion per
sec.)
Peak supply current
(during P or T conversion)
Peak supply current
(during humidity conversion)
Standby supply current
ADC Output Word
ADC Conversion time(3)
3.11
0.78
@ 25°C, VDD = 3V
1.25
mA
0.45
mA
0.03
Pressure and temperature
Condition
Min.
Typ.
Max.
24
OSR 8192
16.44
17.2
4096
8.22
8.61
2048
4.13
4.32
1024
2.08
2.17
512
1.06
1.10
256
0.54
0.56
Heater: power dissipation
and temperature increase
over humidity sensor
Low battery indicator
accuracy
µA
1.56
Min.
Relative humidity
Typ.
Max.
16
13.82
15.89
6.98
8.03
3.55
4.08
1.84
2.12
2 - 13
0.5 - 1.5
±50 (Typ.)
0.24
µA
Unit
bit
ms
mW
°C
mV
(3): Maximum values must be applied to determine waiting times in I2C communication
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PHT Combination Sensor
PERFORMANCE SPECIFICATIONS (CONTINUED)
PHT CHARACTERISTICS (VDD = 3.0 V, T = 25 °C UNLESS OTHERWISE NOTED)
Operating Range
Extended Range (4)
Absolute Accuracy
@25°C
Absolute Accuracy
Relative Accuracy
@25°C
OSR 8192
4096
2048
Resolution
RMS(7)
1024
512
256
Maximum error with
supply voltage
(Condition)
Long-term stability
Reflow soldering impact
Recovering time after
reflow (8)
Pressure [mbar]
Typ.
Max.
1200
2000
300…1100 mbar
-2
2
300…1100mbar, -20...85°C
-4
4
700…1000 mbar (5)
±0.1 (6)
0.016
0.021
0.028
0.039
0.062
0.11
Relative Humidity [%RH]
Min.
Typ.
Max.
0.04
0.7
0.002
0.003
0.004
0.006
0.009
0.012
±0.5
±0.25
±0.3
Min.
300
10
0
Min.
100
-40
3
-1
5
-2
20 …80%RH
-3
85
@25°C
5…95%RH
-5
Temperature [°C]
Typ.
Max.
1
-20...85°C
2
(VDD = 1.5 V … 3.6 V)
Response Time
±1 / year
-0.6
±0.5 / year
2
5 days
5 days
< 5ms
5 sec.
±0.3 / year
(at 63% of signal recovery,
From 33%RH to 75%RH,
At 3m/s air flow)
(Condition)
(4): Linear range of ADC
(5): Auto-zero at one pressure point
(6): Characterized value performed on qualification devices
(7): Characterization performed sequentially (P&T conversion followed by H conversion)
(8): Recovering time at least 66% of the reflow impact
DIGITAL INPUTS (SDA, SCL)
Parameter
Serial data clock
Input high voltage
Input low voltage
Symbol
SCL
VIH
VIL
Conditions
Symbol
VOH
VOL
CLOAD
Conditions
Isource = 1 mA
Isink = 1 mA
Min.
Typ.
Max.
400
100% VDD
20% VDD
Unit
kHz
V
V
Typ.
Max.
100% VDD
20% VDD
Unit
V
V
pF
80% VDD
0% VDD
DIGITAL OUTPUTS (SDA)
Parameter
Output high voltage
Output low voltage
Load Capacitance
SENSOR SOLUTIONS ///MS8607-02BA01
Min.
80% VDD
0% VDD
16
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PHT Combination Sensor
PERFORMANCE CHARACTERISTICS
PHT ACCURACY AND PHT ERROR VERSUS SUPPLY VOLTAGE (TYPICAL)
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PHT Combination Sensor
FUNCTIONAL DESCRIPTION
GENERAL
The MS8607 includes two sensors with distinctive MEMS technologies to measure pressure, humidity and
temperature. The first sensor is a piezo-resistive sensor providing pressure and temperature. The second sensor
is a capacitive type humidity sensor providing relative humidity. Each sensor is interfaced to a ΔΣ ADC integrated
circuit for the digital conversion. The MS8607 converts both analog output voltages to a 24-bit digital value for the
pressure and temperature measurements, and a 12-bit digital value for the relative humidity measurement.
SERIAL I2C INTERFACE
The external microcontroller clocks in the data through the input SCL (Serial CLock) and SDA (Serial DAta). Both
sensors respond on the same pin SDA which is bidirectional for the I 2C bus interface. Two distinct I2C addresses
are used (one for pressure and temperature, the other for relative humidity, see Figure 2).
Module reference
MS860702BA01
Mode
I2C
Pins used
SDA, SCL
Figure 1: Communication Protocol and pins
Sensor type
Pressure and Temperature P&T
Relative Humidity RH
I2C address (binary value)
1110110
1000000
I2C address (hex. value)
0x76
0x40
Figure 2: I2C addresses
COMMANDS FOR PRESSURE AND TEMPERATURE
For pressure and temperature sensing, five commands are possible:
1. Reset
2. Read PROM P&T (112 bit of calibration words)
3. D1 conversion
4. D2 conversion
5. Read ADC (24 bit pressure / temperature)
Each command is represented over 1 byte (8 bits) as described in Figure 3. After ADC read commands, the
device will return 24 bit result and after the PROM read 16 bit results. The address of the PROM is embedded
inside of the read PROM P&T command using the a2, a1 and a0 bits.
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PHT Combination Sensor
Command byte
7
6
PROM CONV
Bit number
Bit name
Command
Reset
Convert D1 (OSR=256)
Convert D1 (OSR=512)
Convert D1 (OSR=1024)
Convert D1 (OSR=2048)
Convert D1 (OSR=4096)
Convert D1 (OSR=8192)
Convert D2 (OSR=256)
Convert D2 (OSR=512)
Convert D2 (OSR=1024)
Convert D2 (OSR=2048)
Convert D2 (OSR=4096)
Convert D2 (OSR=8192)
ADC Read
PROM Read P&T
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
1
1
1
1
1
1
1
1
1
1
1
1
0
0
hex value
5
-
4
Typ
3
Ad2/
Os2
2
Ad1/
Os1
1
Ad0/
Os0
0
Stop
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
1
1
1
1
1
1
0
0
1
0
0
0
0
1
1
0
0
0
0
1
1
0
Ad2
1
0
0
1
1
0
0
0
0
1
1
0
0
0
Ad1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
Ad0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0x1E
0x40
0x42
0x44
0x46
0x48
0x4A
0x50
0x52
0x54
0x56
0x58
0x5A
0x00
0xA0 to 0xAE
Figure 3: Command structure for pressure and temperature sensing
COMMANDS FOR RELATIVE HUMIDITY
For relative humidity sensing, six commands are possible:
1. Reset
2. Write user register
3. Read user register
4. Measure RH (Hold master)
5. Measure RH (No Hold master)
6. PROM read RH
Each I2C communication message starts with the start condition and it is ended with the stop condition. The I2C
address for humidity sensing is 1000000. The address of the PROM is embedded inside of the PROM read
command using the a2, a1 and a0 bits. Figure 4 shows the commands with their respective code:
Bit number
Command :
1. Reset
2. Write user register
3. Read user register
4. Measure RH (Hold master)
5. Measure RH (No Hold master)
6. PROM read RH
8 bits Command
7
6
5
4
1
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
0
0
0
1
0
hex value
3
2
1
0
1
0
0
0
0
adr2
1
1
1
1
1
adr1
1
1
1
0
0
adr0
0
0
1
1
1
0
0xFE
0xE6
0xE7
0xE5
0xF5
0xA0 to 0xAE
Figure 4: command structure for relative humidity sensing
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PHT Combination Sensor
USER REGISTER
The user register is used to configure several operating modes of the humidity sensor (resolution measurements,
heater) and monitor the battery state. The possible configurations of the user register are described in the table
below.
User register Bit
Bit Configuration/Coding
Default value
bit 7, bit 0
Measurement resolution
‘00’
Bit 7
0
0
1
1
bit 6
bit 3,4,5
bit 2
bit 1
Bit 0
0
1
0
1
OSR
4096
2048
1024
256
Resolution
Highest
Lowest
‘0’
Battery state:
‘0’ VDD>2.25V
‘1’ VDD<2.25V
Reserved
on-chip heater:
‘0’ heater disabled
‘1’ heater enabled
Reserved
‘000’
‘0’
‘0’
Figure 5: description of the user register
Bit 7 and bit 0 configure the measurement resolution (highest resolution OSR 4096, lowest OSR 256).
Bit 6 refers to the “Battery state”, which can be monitored.
Bits 1,3,4,5 are reserved bits, which must not be changed and default values of respective reserved bits
may change over time without prior notice. Therefore, for any writing to user register, default values of
reserved bits must be read first.
Bit 2 configures the heater. It can be used for functionality diagnosis: relative humidity drops upon rising
temperature. The heater consumes about 5.5mW and provides a temperature increase of approximatively
0.5-1.5°C over the humidity sensor.
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PHT Combination Sensor
PRESSURE AND TEMPERATURE CALCULATION
Start
Maximum values for calculation results:
PMIN = 10mbar P MAX = 2000mbar
TMIN = -40°C T MAX = 85°C T REF = 20°C
Convert
Read
calibration
calibration
data
data
into
(factory
coefficients
calibrated)
(see from
bit pattern
PROMof W1 to W4)
Variable
Description | Equation
Recommended
variable type
Size [1]
[bit]
min
max
Example /
Typical
C1
Pressure sensitivity | SENS T1
unsigned int 16
16
0
65535
46372
C2
Pressure offset | OFF T1
unsigned int 16
16
0
65535
43981
C3
Temperature coefficient of pressure sensitivity | TCS
unsigned int 16
16
0
65535
29059
C4
Temperature coefficient of pressure offset | TCO
unsigned int 16
16
0
65535
27842
C5
Reference temperature | T
REF
unsigned int 16
16
0
65535
31553
C6
Temperature coefficient of the temperature | TEMPSENS
unsigned int 16
16
0
65535
28165
Value
Read
digital
pressure
and
temperature
data
Read
digital
pressure
and
temperature
data
D1
Digital pressure value
unsigned int 32
24
0
16777215
6465444
D2
Digital temperature value
unsigned int 32
24
0
16777215
8077636
signed int 32
25
-16776960
16777215
68
signed int 32
41
-4000
8500
Calculate temperature
dT
Difference between actual and reference temperature
8
dT = D2 - T REF = D2 - C5 * 2
TEMP
Actual temperature (-40…85°C with 0.01°C resolution)
TEMP = 20°C + dT * TEMPSENS = 2000 + dT * C6 / 223
[2]
2000
= 20.00 °C
Calculate
temperature
compensated
pressure
Calculate
temperature
compensated
pressure
OFF
Offset at actual temperature [3]
OFF = OFFT1 + TCO * dT = C2 * 217 + (C4 * dT ) / 26
signed int 64
41
-17179344900
25769410560
5764707214
SENS
Sensitivity at actual temperature [4]
16
SENS = SENS T1 + TCS * dT = C1 * 2 + (C3 * dT ) / 27
signed int 64
41
-8589672450
12884705280
3039050829
P
Temperature compensated pressure (10…1200mbar with
0.01mbar resolution)
21
15
P = D1 * SENS - OFF = (D1 * SENS / 2
- OFF) / 2
signed int 32
58
1000
120000
110002
= 1100.02 mbar
Pressure and temperature value first order
Notes
[1]
[2]
[3]
[4]
Maximal size of intermediate result during evaluation of variable
min and max have to be defined
min and max have to be defined
min and max have to be defined
Figure 6: Flow chart for pressure and temperature reading and software compensation.
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PHT Combination Sensor
PRESSURE COMPENSATION (SECOND ORDER OVER TEMPERATURE)
In order to optimize the accuracy over temperature range at low temperature, it is recommended to compensate
the pressure non-linearity over the temperature. This can be achieved by correcting the calculated temperature,
offset and sensitivity by a second-order correction factor. The second-order factors are calculated as follows:
No
Yes
TEMP<20°C
Low temperature
Low
temperature
High temperature
T2 = T2 = 5 dT / 2
OFF2 = 0
SENS2 = 0
T2 = 3 dT / 2
OFF2 = 61 (TEMP – 2000)2 / 24
SENS2 = 29 (TEMP – 2000)2/ 24
2
Yes
33
TEMP<-15°C
2
38
No
temperature
VeryLow
low
temperature
OFF2 = OFF2 + 17 (TEMP + 1500)2
SENS2 = SENS2 + 9 (TEMP + 1500)2
Calculate pressure and temperature
TEMP = TEMP - T2
OFF = OFF - OFF2
SENS = SENS - SENS2
Figure 7: Flow chart for pressure and temperature to the optimum accuracy.
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PHT Combination Sensor
RELATIVE HUMIDITY CALCULATION
Start
Maximum values for calculation results:
RH MIN = -6 %RH RH MAX= 118 %RH
Read
digital
relative
humidity
data
Read
digital
pressure
and temperature
data
Recommended Size[1]
variable type
[bit]
Variable Description | Equation
D3
Digital relative humidity value
unsigned int 16
Value
min
max
Example /
Typical
16
0
65535
31872
31
- 600
11900
Calculate relative humidity
RH
Actual relative humidity (-6 %RH…118%RH
with 0.01 %RH resolution)
16
RH = - 600 + 12500 * D3 / 2
signed int 16
5480
= 54.8 %RH
Display relative humidity value
Notes
[1]
Maximal size of intermediate result during evaluation of variable
Figure 8: Flow chart for humidity reading.
To accommodate any process variation (nominal capacitance value of the humidity sensor), tolerances of the sensor
above 100%RH and below 0%RH must be considered. As a consequence:
118%RH corresponds to 0xFF which is the maximum RH digital output that can be sent out from the ASIC. RH
output can reach 118%RH and above this value, there will have a clamp of the RH output to this value.
-6%RH corresponds to 0x00 which is the minimum RH digital output that can be sent out from the ASIC. RH
output can reach -6%RH and below this value, there will have a clamp of the RH output to this value.
The relative humidity is obtained by the following formula (result in %RH):
D3
RH 6 125 16
2
As example, the transferred 16-bit relative humidity data 0x7C80: 31872 corresponds to a relative humidity of
54.8%RH.
Finally, 1st order temperature compensation is computed for optimal accuracy over [0…+85°C] temperature
range. The final compensated relative humidity value RHcompensated is calculated as:
RH compensated RH 20 TEMP Tcoeff
TEMP
Temperature calculated on p.9
unit [°C]
Tcoeff
Temperature correction coefficient
unit [%RH / °C]
Optimal relative humidity accuracy over [0…+85°C] temperature range is obtained with Tcoeff = -0.18
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PHT Combination Sensor
APPLICATION CIRCUIT
The MS8607 is a circuit that can be used in conjunction with a microcontroller by I2C protocol interface. It is
designed for low-voltage systems with a supply voltage of 3 V and can be used in industrial pressure / humidity /
temperature applications.
Figure 9: Typical application circuit
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PHT Combination Sensor
I2C INTERFACE: PRESSURE AND TEMPERATURE
COMMANDS
Each I2C communication message starts with the start condition and it is ended with the stop condition. The I 2C
address for pressure and temperature sensing is 1110110. The description of the commands related to pressure
and temperature sensing is detailed on p. 5.
RESET SEQUENCE
The Reset sequence shall be sent once after power-on to make sure that the calibration PROM gets loaded into
the internal register. It can be also used to reset the device PROM from an unknown condition.
The reset can be sent at any time. In the event that there is not a successful power on reset this may be caused
by the SDA being blocked by the module in the acknowledge state. The only way to get the ASIC to function is to
send several SCLs followed by a reset sequence or to repeat power on reset.
1 1 1 0 1 1 0 0 0 0 0 0 1 1 1 1 0 0
Device Address
command
S
Device Address
W A
cmd byte
A P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledge
Figure 10: I2C Reset Command
PROM READ P&T SEQUENCE
The read command for PROM shall be executed once after reset by the user to read the content of the calibration
PROM and to calculate the calibration coefficients. There are in total 7 addresses resulting in a total memory of
112 bit. The addresses contain factory data and the setup, calibration coefficients, the serial code and CRC (see
details on p. 15, Figure 22). The command sequence is 8 bits long with a 16 bit result which is clocked with the
MSB first. The PROM Read command consists of two parts. First command sets up the system into PROM read
mode (Figure 11). The second part gets the data from the system (Figure 12).
1 1 1 0 1 1 0 0 0 1 0 1 0 0 1 1 0 0
Device Address
command
S
Device Address
W A
cmd byte
A P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledge
Figure 11: I2C Command to read P&T memory PROM address 0xA6
1 1 1 0 1 1 0 1 0 X X X X X X X X 0 X X X X X X X X 0
Device Address
data
data
S
Device Address
R A
Memory bit 15 - 8
A
Memory bit 7 - 0
N P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledage
Figure 12: I2C answer from ASIC (Pressure and temperature)
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CONVERSION SEQUENCE
The conversion command is used to initiate uncompensated pressure (D1) or uncompensated temperature (D2)
conversion. After the conversion, using ADC read command the result is clocked out with the MSB first. If the
conversion is not executed before the ADC read command, or the ADC read command is repeated, it will give 0
as the output result. If the ADC read command is sent during conversion the result will be 0, the conversion will
not stop and the final result will be wrong. Conversion sequence sent during the already started conversion
process will yield incorrect result as well. A conversion can be started by sending the command to the ASIC.
When the command is sent to the system it stays busy until conversion is done. When conversion is finished, the
data can be accessed by sending a Read command. When the Acknowledge bit is sent from the ASIC, 24 SCL
cycles may be sent to receive all result bits. Every 8 bits the system waits for the Acknowledge bit.
1 1 1 0 1 1 0 0 0 0 1 0 0 1 0 0 0 0
Device Address
command
S
Device Address
W A
cmd byte
A P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledge
Figure 13: I2C command to initiate a pressure conversion (OSR=4096, typ=D1)
1 1 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0
Device Address
command
S
Device Address
W A
cmd byte
A P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledge
Figure 14: I2C ADC read sequence
1 1 1 0 1 1 0 1 0 X X X X X X X X 0 X X X X X X X X 0 X X X X X X X X 0
Device Address
S
Device Address
R A
Data 23 - 16
A
Data 15 - 8
A
Data 7 - 0
N P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledge
Figure 15: I2C answer from the ASIC
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PHT Combination Sensor
I2C INTERFACE: RELATIVE HUMIDITY
COMMANDS
Each I2C communication message starts with the start condition and it is ended with the stop condition. The I2C
address for humidity sensing is 1000000. The description of the commands related to humidity sensing is detailed
on p. 6.
RESET SEQUENCE
This command is used for rebooting the humidity sensor by switching the power off and on again. Upon reception
of this command, the humidity sensor system reinitializes and starts operation according to the default settings
with the exception of the heater bit in the user register. The reset takes less than 15ms.
1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0
Device Address
command
S
W A
A P
Device Address
cmd byte
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledge
Figure 16: I2C Reset Command
READ AND WRITE USER REGISTER SEQUENCE
The following sequence illustrates how to read and write the user register. First, it reads the content of the user
register. Then it writes the user register for configuring the humidity sensor to 8 bits measurement resolution from
the default configuration.
1 0 0 0 0 0 0 0 0 1 1 1 0 0 1 1 1 0
Device Address
command
Device Address
cmd byte
S
W A
A
1 0 0 0 0 0 0 1 0 X X X X X X X X 0
Device Address
Device Address
S
R A User Register Data 7 - 0 N
1 0 0 0 0 0 0 0 0 1 1 1 0 0 1 1 0 0 0 0 0 0 0 0 0 1 0
Device Address
command
Device Address
cmd byte
S
W A
A User Register Data 7 - 0 A P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledge
Figure 17: I2C read and write user register commands
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MEASURE RH HOLD/NO HOLD SEQUENCE
MS8607 has two different operation modes to measure relative humidity (RH): Hold Master mode and No Hold
Master mode.
No Hold Master mode allows for processing other I²C communication tasks on a bus while the humidity sensor is
measuring. Figure 18 and 19 illustrate the communication sequence of both modes. In the Hold Master mode, the
humidity sensor pulls down the SCK line while measuring to force the master into a wait state. By releasing the
SCK line, the humidity sensor indicates that internal processing is completed and that transmission may be
continued.
In the No Hold Master mode, the MCU has to poll for the termination of the internal processing of the humidity
sensor. This is done by sending a start condition followed by the I²C header (0x81) as shown below. If the internal
processing is finished, the humidity sensor acknowledges the poll of the MCU and data can be read by the MCU.
If the measurement processing is not finished, the humidity sensor answers the Not Acknowledge bit and start
condition must be issued once more.
For both modes, the measurement is stored into 14 bits. The two remaining least significant bits (LSBs) are used
for transmitting status information. Bit1 of the two LSBs must be set to ‘1’. Bit0 is currently not assigned.
1 0 0 0 0 0 0 0 0 1 1 1 0 0 1 0 1 0
Device Address
command
Device Address
cmd byte
S
W A
A
1 0 0 0 0 0 0 1 0
Device Address
Hold during measurement
S
Device Address
R A Hold during measurement
1 0 0 1 0 1 1 1 0
Checksum
N P
From Master
From Slave
On hold
X X X X X X X X 0 X X X X X X 1 0 0
Data 15 - 8
S = Start Condition
P = Stop Condition
A
Data 7 - 2
Status A
W = Write A = Acknowledge
R = Read N = Not Acknowledge
Figure 18: I2C Measure RH Hold Master communication sequence
1 0 0 0 0 0 0 0 0 1 1 1 1 0 1 0 1 0
Device Address
command
Device Address
cmd byte
S
W A
A
1 0 0 0 0 0 0 1 0 X X X X X X X X 0 X X X X X X 1 0 0 1 0 0 1 0 1 1 1 0
Device Address
Device Address
Data 15 - 8
Data 7 - 2
Status A
S
R A
A
Checksum
N P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write A = Acknowledge
R = Read N = Not Acknowledge
Figure 19: I2C Measure RH No Hold Master communication sequence
For Hold Master sequence, the Acknowledge bit that follows the Status bit may be changed to Not Acknowledge
bit followed by a stop condition to omit checksum transmission.
For No Hold Master sequence, if measurement is not completed upon “read” command, sensor does not provide
ACK on bit 27 (more of these iterations are possible). If bit 45 is changed to NACK followed by stop condition,
checksum transmission is omitted.
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Regarding the calculation of the relative humidity value, the Status bits must be set to ‘0’. Refer to “Conversion of
signal outputs” section p. 10. The maximum duration for measurement depends on the type of measurement and
resolution chosen. Maximum values shall be chosen for the communication planning of the MCU.
I²C communication allows for repeated start conditions without closing prior sequence with stop condition.
PROM READ RH
Bit
14
Bit
13
Bit
12
Bit
11
Bit
10
Bit
9
Bit
8
Bit
7
Bit
6
Bit
5
Bit
4
Bit
3
Bit
2
Bit
1
Bit
0
SEQUENCE
The RH PROM memory contains 7 addresses resulting in a total memory of 112 bit. The addresses contain
factory defined data and CRC (see details on p. 17, Figure 23). The command sequence is 8 bits long with a 16
bit result which is clocked with the MSB first. The RH PROM Read command consists of two parts. First
command sets up the system into PROM read mode (Figure 20). The second part gets the data from the system
(Figure 21).
1 1 1 0 1 1 0 0 0 1 0 1 0 0 1 1 0 0
Device Address
command
S
Device Address
W A
cmd byte
A P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledge
Figure 20: I2C Command to read memory address 0xA6
1 1 1 0 1 1 0 1 0 X X X X X X X X 0 X X X X X X X X 0
Device Address
data
data
S
Device Address
R A
Memory bit 15 - 8
A
Memory bit 7 - 0
N P
From Master
From Slave
S = Start Condition
P = Stop Condition
W = Write
R = Read
A = Acknowledge
N = Not Acknowledage
Figure 21: I2C answer from ASIC (Pressure and temperature)
CYCLIC REDUNDANCY CHECK (CRC)
MS8607 contains two separate PROM memories with identical size (112-Bit): one for pressure and temperature
P&T (Figure 22), the other for relative humidity RH (Figure 23). Each PROM memory can be accessed using the
I2C commands PROM Read P&T and PROM Read RH (p. 6).
Address
(Hex.)
0xA0
0xA2
0xA4
0xA6
0xA8
0xAA
0xAC
Bit
15
Bit
14
Bit
13
Bit
12
Bit
11
Bit
10
Bit
9
Bit
8
Bit
7
CRC
Bit
6
Bit
5
Bit
4
Bit
3
Bit
2
Bit
1
Bit
0
Factory defined
C1
C2
C3
C4
C5
C6
Figure 22: P&T Memory PROM mapping for pressure and temperature
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Address
(Hex.)
Bit
15
Bit
14
Bit
13
Bit
12
Bit
11
Bit
10
Bit
9
Bit
8
Bit
7
Bit
6
Bit
5
Bit
4
Bit
3
Factory defined
Factory defined
Factory defined
Factory defined
Factory defined
Factory defined
Factory defined
0xA0
0xA2
0xA4
0xA6
0xA8
0xAA
0xAC
Bit
2
Bit
1
Bit
0
CRC
Figure 23: RH Memory PROM mapping for relative humidity
A 4-bit CRC has been implemented to check the data integrity in both PROM memories. The C code below
describes the CRC calculation for P&T Memory PROM and for RH Memory PROM.
C CODE EXAMPLE FOR CRC-4 CALCULATION (P&T MEMORY PROM)
unsigned char crc4_PT(unsigned int n_prom[])
{
int cnt;
unsigned int n_rem=0;
unsigned char n_bit;
// n_prom defined as 8x unsigned int (n_prom[8])
// simple counter
// crc remainder
n_prom[0]=((n_prom[0]) & 0x0FFF);
// CRC byte is replaced by 0
n_prom[7]=0;
// Subsidiary value, set to 0
for (cnt = 0; cnt < 16; cnt++)
// operation is performed on bytes
{
// choose LSB or MSB
if (cnt%2==1)
n_rem ^= (unsigned short) ((n_prom[cnt>>1]) & 0x00FF);
else
n_rem ^= (unsigned short) (n_prom[cnt>>1]>>8);
for (n_bit = 8; n_bit > 0; n_bit--)
{
if (n_rem & (0x8000))
n_rem = (n_rem << 1) ^ 0x3000;
else
n_rem = (n_rem << 1);
}
}
n_rem= ((n_rem >> 12) & 0x000F);
// final 4-bit remainder is CRC code
return (n_rem ^ 0x00);
}
C CODE EXAMPLE FOR CRC-4 CALCULATION (RH MEMORY PROM)
unsigned char crc4_RH(unsigned int n_prom[])
{
int cnt;
unsigned int n_rem=0;
unsigned char n_bit;
// n_prom defined as 8x unsigned int (n_prom[8])
// simple counter
// crc remainder
n_prom[6]=((n_prom[6]) & 0xFFF0);
// CRC byte is replaced by 0
n_prom[7]=0;
// Subsidiary value, set to 0
for (cnt = 0; cnt < 16; cnt++)
// operation is performed on bytes
{
// choose LSB or MSB
if (cnt%2==1)
n_rem ^= (unsigned short) ((n_prom[cnt>>1]) & 0x00FF);
else
n_rem ^= (unsigned short) (n_prom[cnt>>1]>>8);
for (n_bit = 8; n_bit > 0; n_bit--)
{
if (n_rem & (0x8000))
n_rem = (n_rem << 1) ^ 0x3000;
else
n_rem = (n_rem << 1);
}
}
n_rem= ((n_rem >> 12) & 0x000F);
// final 4-bit remainder is CRC code
return (n_rem ^ 0x00);
}
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PIN CONFIGURATION
Type
Function
1
Nam
e
VDD
P
Positive supply voltage
3
GND
G
Ground
7
SDA
IO
I2C data IO
8
SCL
SCL
NC
I
Serial data clock
Pin
2,4,5,6
DEVICE PACKAGE OUTLINE
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RECOMMENDED PAD LAYOUT
Pad layout for bottom side of the MS8607-02BA01 soldered onto printed circuit board.
Reserved area:
Please do not route
tracks between pads
SHIPPING PACKAGE
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MOUNTING AND ASSEMBLY CONSIDERATIONS
SOLDERING
Please refer to the application note AN808 available on our website for all soldering issues.
MOUNTING
The MS8607 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. It is
important to solder all contact pads.
CONNECTION TO PCB
The package outline of the module allows the use of a flexible PCB for interconnection. This can be important for
applications in watches and other special devices.
CLEANING
The MS8607 has been manufactured under cleanroom conditions. 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 up to 2 kV HBM (human body model). It is therefore
essential to ground machines and personnel properly during assembly and handling of the device. The MS8607 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.
DECOUPLING CAPACITOR
Particular care must be taken when connecting the device to the power supply. A minimum 220nF ceramic
capacitor must be placed as close as possible to the MS8607 VDD pin. This capacitor will stabilize the power
supply during data conversion and thus, provide the highest possible accuracy.
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ORDERING INFORMATION
Part Number / Art. Number
Product
Delivery Form
MS860702BA01-50
PHT Combination Sensor Module 5x3mm
Tape & Reel
NORTH AMERICA
EUROPE
ASIA
Measurement Specialties, Inc.,
a TE Connectivity Company
45738 Northport Loop West
Fremont, CA 94538
Tel: +1 800 767 1888
Fax: +1 510 498 1578
e-mail: [email protected]
Website: www.meas-spec.com
Measurement Specialties (Europe), Ltd.,
a TE Connectivity Company
Switzerland Sàrl
Ch. Chapons-des-Prés 11
CH-2022 Bevaix
Tel: +41 32 847 9550
Fax: + 41 32 847 9569
e-mail: [email protected]
Website: www.meas-spec.com
Measurement Specialties (China), Ltd.,
a TE Connectivity Company
No. 26 Langshan Road
Shenzhen High-Tech Park (North) Nanshan
District, Shenzhen, 518057 China
Tel: +86 755 3330 5088
Fax: +86 755 3330 5099
e-mail: [email protected]
Website: www.meas-spec.com
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 believed 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.
DA8607-02BA01_003
000086072885 ECN2515
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