SENSOR SOLUTIONS ///MS8607-02BA01 Page 1
06/2017
MS8607-02BA01
PHT Combination Sensor
SPECIFICATIONS
• Integrated pressure, humidity and temperature sensor
• QFN package 5 x 3 x 1 mm
3
• 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
• I
2
C 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.
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 2
FEATURES
FIELD OF APPLICATION
• Smart phones and Tablet PCs
• HVAC applications
• Weather station
• Printers
• Home Appliance and humidifiers
TECHNICAL DATA
Sensor Performances (V
DD
= 3 V)
Characteristics Pressure [mbar] Relative Humidity [%RH] Temperature [°C]
Min Typ Max Min Typ Max Min Typ Max
Max. Operating Range 10 2000 0 100 -40 +85
Absolute Accuracy @25°C 300…1100mbar 20…80%RH @ 25°C
-2 2 -3 3 -1 1
Resolution (highest mode) 0.016 0.04 0.01
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 3
PERFORMANCE SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Parameter
Symbol
Condition
Min.
Max.
Unit
Supply voltage V
DD
-0.3 3.6 V
Storage temperature T
S
-20 85 °C
Overpressure P
max
6 bar
Maximum Soldering
Temperature T
max
40 sec max 250 °C
ESD rating Human Body Model -2 2 kV
Latch up JEDEC standard No 78 -100 100 mA
ELECTRICAL CHARACTERISTICS
Parameter
General electrical characteristics
Symbol Condition Min. Typ. Max. Unit
Operating Supply voltage V
DD
1.5 3.0 3.6 V
Operating Temperature T -40 +25 +85 °C
VDD to GND Capacitor
220 470 nF
Supply current P or T
(1 Pressure or temperature
conversion per sec.) I
PT
OSR 8192
4096
2048
1024
512
256
20.09
10.05
5.02
2.51
1.26
0.63
µA
Supply current H
(1 humidity conversion per
sec.) I
H
OSR 8192
4096
2048
1024
6.22
3.11
1.56
0.78
µA
Peak supply current
(during P or T conversion) 1.25 mA
Peak supply current
(during humidity conversion) 0.45 mA
Standby supply current
@ 25°C, V
DD
= 3V 0.03 0.24 µA
Pressure and temperature Relative humidity
Condition Min. Typ. Max. Min. Typ. Max. Unit
ADC Output Word 24 16 bit
ADC Conversion time
(3)
OSR 8192
4096
2048
1024
512
256
16.44
8.22
4.13
2.08
1.06
0.54
17.2
8.61
4.32
2.17
1.10
0.56
13.82
6.98
3.55
1.84
-
-
15.89
8.03
4.08
2.12
-
-
ms
Heater: power dissipation
and temperature increase
over humidity sensor 2 - 13
0.5 - 1.5 mW
°C
Low battery indicator
accuracy ±50 (Typ.) mV
(3): Maximum values must be applied to determine waiting times in I
2
C communication
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 4
PERFORMANCE SPECIFICATIONS (CONTINUED)
PHT CHARACTERISTICS (V
DD
= 3.0 V, T = 25 °C UNLESS OTHERWISE NOTED
)
Pressure [mbar] Relative Humidity [%RH] Temperature [°C]
Min. Typ. Max. Min. Typ. Max. Min. Typ. Max.
Operating Range
Extended Range
(4)
300
10 1200
2000 0 100 -40 85
Absolute Accuracy
@25°C 300…1100 mbar 20 …80%RH @25°C
-2 2 -3 3 -1 1
Absolute Accuracy 300…1100mbar, -20...85°C 5…95%RH -20...85°C
-4 4 -5 5 -2 2
Relative Accuracy
@25°C 700…1000 mbar
(5)
±0.1
(6)
Resolution
RMS
(7)
OSR 8192
4096
2048
1024
512
256
0.016
0.021
0.028
0.039
0.062
0.11
0.04
-
-
0.7
0.002
0.003
0.004
0.006
0.009
0.012
Maximum error with
supply voltage
(Condition)
±0.5 ±0.25 ±0.3
(V
DD
= 1.5 V … 3.6 V)
Long-term stability ±1 / year ±0.5 / year ±0.3 / year
Reflow soldering impact -0.6 2
Recovering time after
reflow
(8)
5 days 5 days
Response Time
(Condition)
< 5ms 5 sec.
(at 63% of signal recovery,
From 33%RH to 75%RH,
At 3m/s air flow)
(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
Symbol
Conditions
Min.
Max.
Unit
Serial data clock SCL 400 kHz
Input high voltage V
IH
80% V
DD
100% V
DD
V
Input low voltage V
IL
0% V
DD
20% V
DD
V
DIGITAL OUTPUTS (SDA)
Parameter
Symbol
Conditions
Min.
Max.
Unit
Output high voltage V
OH
I
source
= 1 mA 80% V
DD
100% V
DD
V
Output low voltage V
OL
I
sink
= 1 mA 0% V
DD
20% V
DD
V
Load Capacitance C
LOAD
16 pF
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 5
PERFORMANCE CHARACTERISTICS
PHT ACCURACY AND PHT ERROR VERSUS SUPPLY VOLTAGE (TYPICAL)
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 6
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 ∆Σ 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 I
2
C 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
2
C bus interface. Two distinct I
2
C addresses
are used (one for pressure and temperature, the other for relative humidity, see Figure 2).
Module reference Mode Pins used
MS860702BA01 I
2
C SDA, SCL
Figure 1: Communication Protocol and pins
Sensor type I
2
C address (binary value) I
2
C address (hex. value)
Pressure and Temperature P&T 1110110 0x76
Relative Humidity RH 1000000 0x40
Figure 2: I
2
C 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.
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 7
Command byte
hex value
Bit number 7 6 5 4 3 2 1 0
Bit name PROM
CONV
- Typ Ad2/
Os2 Ad1/
Os1 Ad0/
Os0 Stop
Command
Reset 0 0 0 1 1 1 1 0 0x1E
Convert D1 (OSR=256) 0 1 0 0 0 0 0 0 0x40
Convert D1 (OSR=512) 0 1 0 0 0 0 1 0 0x42
Convert D1 (OSR=1024) 0 1 0 0 0 1 0 0 0x44
Convert D1 (OSR=2048) 0 1 0 0 0 1 1 0 0x46
Convert D1 (OSR=4096) 0 1 0 0 1 0 0 0 0x48
Convert D1 (OSR=8192) 0 1 0 0 1 0 1 0 0x4A
Convert D2 (OSR=256) 0 1 0 1 0 0 0 0 0x50
Convert D2 (OSR=512) 0 1 0 1 0 0 1 0 0x52
Convert D2 (OSR=1024) 0 1 0 1 0 1 0 0 0x54
Convert D2 (OSR=2048) 0 1 0 1 0 1 1 0 0x56
Convert D2 (OSR=4096) 0 1 0 1 1 0 0 0 0x58
Convert D2 (OSR=8192) 0 1 0 1 1 0 1 0 0x5A
ADC Read 0 0 0 0 0 0 0 0 0x00
PROM Read P&T 1 0 1 0 Ad2 Ad1 Ad0 0 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 I
2
C
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:
8 bits Command
hex
value
Bit number 7 6 5 4 3 2 1 0
Command :
1. Reset 1 1 1 1 1 1 1 0 0xFE
2. Write user register
1 1 1 0 0 1 1 0 0xE6
3. Read user register
1 1 1 0 0 1 1 1 0xE7
4. Measure RH (Hold master)
1 1 1 0 0 1 0 1 0xE5
5. Measure RH (No Hold master)
1 1 1 1 0 1 0 1 0xF5
6. PROM read RH 1 0 1 0 adr2
adr1 adr0
0 0xA0 to 0xAE
Figure 4: command structure for relative humidity sensing
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 8
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
Bit 7 Bit 0 OSR Resolution
0 0 4096 Highest
0 1 2048
1 0 1024
1 1 256 Lowest
‘00’
bit 6 Battery state:
‘0’ VDD>2.25V
‘1’ VDD<2.25V
‘0’
bit 3,4,5 Reserved ‘000’
bit 2 on-chip heater:
‘0’ heater disabled
‘1’ heater enabled
‘0’
bit 1 Reserved ‘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.
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 9
PRESSURE AND TEMPERATURE CALCULATION
Figure 6: Flow chart for pressure and temperature reading and software compensation.
Size
[1]
[bit]
min
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
D1
Digital pressure value unsigned int 32 24 0 16777215 6465444
D2
Digital temperature value
unsigned int 32 24 0 16777215 8077636
dT
Difference between actual and reference temperature
[2]
dT
= D2 - TREF
=
D2
- C5 * 2
8
signed int 32
25 -16776960 16777215 68
2000
= 20.00 °C
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]
SENS
=
SENST1 + TCS
*
dT
=
C1 * 2
16
+ (C3
*
dT
)
/ 27
signed int 64
41 -8589672450 12884705280 3039050829
110002
= 1100.02 mbar
Notes
[1]
[2]
[3]
[4]
min and max have to be defined
min and max have to be defined
Maximal size of intermediate result during evaluation of variable
120000100058
P
Recommended
variable type
Description | Equation
signed int 32
Actual temperature (-40…85°C with 0.01°C resolution)
TEMP
=
20°C +
dT
*
TEMPSENS
=
2000 + dT
*
C6
/
223
Read digital pressure and temperature data
signed int 32
Temperature compensated pressure (10…1200mbar with
0.01mbar resolution)
P
= D1 * SENS -
OFF =
(D1 * SENS / 2
21 -
OFF) / 2
15
min and max have to be defined
Convert calibration data into coefficients (see bit pattern of W1 to W4)
Variable
Example /
Typical
Value
Calculate temperature compensated pressure
8500-4000
TEMP
41
Start
Maximum values for calculation results:
PMIN
= 10mbar P
MAX
= 2000mbar
T
MIN
= -40°C T
MAX
= 85°C T
REF
= 20°C
Read calibration data (factory calibrated) from PROM
Read digital pressure and temperature data
Calculate temperature
Calculate temperature compensated pressure
Pressure and temperature value first order
max
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 10
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:
Figure 7: Flow chart for pressure and temperature to the optimum accuracy.
Yes
No
SENS2 = 29 ⋅ (TEMP – 2000)2/ 24
SENS2 = 0
SENS = SENS - SENS2
TEMP<20°C
Low temperature
T2 = 3 ⋅ dT
2
/ 2
33
OFF2 = 0
T2 = T2 = 5 ⋅ dT / 2
2
3
8
OFF2 = 61 ⋅ (TEMP – 2000)2 / 24
OFF = OFF - OFF2
TEMP = TEMP - T2
Low temperature
High temperature
Calculate pressure and temperature
TEMP<
-
15°C
No
Yes
SENS2 = SENS2 + 9 ⋅ (TEMP + 1500)2
Low temperature
OFF2 = OFF2 + 17 ⋅ (TEMP + 1500)2
Very low temperature
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 11
RELATIVE HUMIDITY CALCULATION
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):
⋅+−=
16
23
1256 D
RH
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] temperatur e
range. The final compensated relative humidity value RH
compensated
is calculated as:
(
)
coeffdcompensate
TTEMPRHRH
⋅
−
+
=
20
TEMP Temperature calculated on p.9 unit [°C]
T
coeff
Temperature correction coefficient unit [%RH / °C]
Optimal relative humidity accuracy over [0…+85°C] temperature range is obtained with
T
coeff
= -0.18
D3
Digital relative
humidity value
unsigned int 16
16 0 65535 31872
RH
Actual relative humidity (-
6 %RH…118%RH
RH
= -
600 + 12500 * D3 / 2
signed int 16
31 - 600 11900
= 54.8 %RH
Notes
[1]
Maximal size of intermediate result during evaluation of variable
Read digital pressure and temperature data
Start
Maximum values for calculation results:
RH
MIN
= -6 %RH RH
MAX
= 118 %RH
Read digital relative humidity
data
Calculate relative humidity
Display relative humidity value
Description | Equation Recommended
variable type Size[1] Value
min max
[bit]
Variable Example /
Typical
16
5480
with 0.01 %RH resolution)
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 12
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
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 13
I
2
C INTERFACE: PRESSURE AND TEMPERATURE
COMMANDS
Each I
2
C communication message starts with the start condition and it is ended with the stop condition. The I
2
C
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.
Figure 10: I
2
C 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).
Figure 11: I
2
C Command to read P&T memory PROM address 0xA6
Figure 12: I
2
C answer from ASIC (Pressure and temperature)
1
1
1
0
1
1
0
0
0
0
0
0
1
1
1
1
0
0
S
W
A
A
P
From Master
S = Start Condition
W = Write
A = Acknowledge
From Slave
P = Stop Condition
R = Read
N = Not Acknowledge
cmd byte
Device Address
Device Address
command
1
1
1
0
1
1
0
0
0
1
0
1
0
0
1
1
0
0
S
W
A
A
P
From Master
S = Start Condition
W = Write
A = Acknowledge
From Slave
P = Stop Condition
R = Read
N = Not Acknowledge
Device Address
Device Address
cmd byte
command
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
S
R
A
A
N
P
From Master
S = Start Condition
W = Write
A = Acknowledge
From Slave
P = Stop Condition
R = Read
N = Not Acknowledage
Memory bit 7 - 0
Device Address
Device Address
Memory bit 15 - 8
data
data
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 14
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.
Figure 13: I
2
C command to initiate a pressure conversion (OSR=4096, typ=D1)
Figure 14: I
2
C ADC read sequence
Figure 15: I
2
C answer from the ASIC
1
1
1
0
1
1
0
0
0
0
1
0
0
1
0
0
0
0
S
W
A
A
P
From Master
S = Start Condition
W = Write
A = Acknowledge
From Slave
P = Stop Condition
R = Read
N = Not Acknowledge
cmd byte
Device Address
Device Address
command
1
1
1
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
S
W
A
A
P
From Master
S = Start Condition
W = Write
A = Acknowledge
From Slave
P = Stop Condition
R = Read
N = Not Acknowledge
Device Address
Device Address
cmd byte
command
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
S R A A A N P
From Master S = Start Condition W = Write A = Acknowledge
From Slave P = Stop Condition R = Read N = Not Acknowledge
Data 23 - 16 Data 7 - 0Data 15 - 8Device Address
Device Address
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 15
I
2
C 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.
Figure 16: I
2
C 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.
Figure 17: I
2
C read and write user register commands
1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0
S W A A P
From Master S = Start Condition W = Write A = Acknowledge
From Slave P = Stop Condition R = Read N = Not Acknowledge
Device Address cmd byte
commandDevice Address
1 0 0 0 0 0 0 0 0 1 1 1 0 0 1 1 1 0
S W A A
1 0 0 0 0 0 0 1 0 X X X X X X X X 0
S R A N
100000000111001100000000010
S W A A A P
From Master S = Start Condition W = Write A = Acknowledge
From Slave P = Stop Condition R = Read N = Not Acknowledge
command
Device Address
Device Address User Register Data 7 - 0
Device Address command
Device Address cmd byte User Register Data 7 - 0
Device Address cmd byte
Device Address
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 16
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.
Figure 18: I
2
C Measure RH Hold Master communication sequence
Figure 19: I
2
C 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.
100000000111001010
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
Hold during measurement
S R A A A
1 0 0 1 0 1 1 1 0 From Master S = Start Condition W = Write A = Acknowledge
From Slave P = Stop Condition R = Read N = Not Acknowledge
Checksum N P On hold
Device Address command
Device Address cmd byte
Device Address Data 15 - 8 Data 7 - 2
Status
Device Address
Hold during measurement
100000000111101010
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
S R A A A Checksum N P
From Master S = Start Condition W = Write A = Acknowledge
From Slave P = Stop Condition R = Read N = Not Acknowledge
Data 7 - 2
Status
Device Address cmd byte
Device Address
Device Address command
Device Address Data 15 - 8
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 17
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 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).
Figure 20: I
2
C Command to read memory address 0xA6
Figure 21: I
2
C 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
I
2
C commands PROM Read P&T and PROM Read RH (p. 6).
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
Bit
2
Bit
1
Bit
0
0xA0
CRC Factory defined
0xA2
C1
0xA4
C2
0xA6
C3
0xA8
C4
0xAA
C5
0xAC
C6
Figure 22: P&T Memory PROM mapping for pressure and temperature
1
1
1
0
1
1
0
0
0
1
0
1
0
0
1
1
0
0
S
W
A
A
P
From Master
S = Start Condition
W = Write
A = Acknowledge
From Slave
P = Stop Condition
R = Read
N = Not Acknowledge
Device Address
Device Address
cmd byte
command
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
S
R
A
A
N
P
From Master
S = Start Condition
W = Write
A = Acknowledge
From Slave
P = Stop Condition
R = Read
N = Not Acknowledage
Memory bit 7 - 0
Device Address
Device Address
Memory bit 15 - 8
data
data
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
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 18
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
Bit
2
Bit
1
Bit
0
0xA0
Factory defined
0xA2
Factory defined
0xA4
Factory defined
0xA6
Factory defined
0xA8
Factory defined
0xAA
Factory defined
0xAC
Factory defined 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[]) // n_prom defined as 8x unsigned int (n_prom[8])
{
int cnt; // simple counter
unsigned int n_rem=0; // crc remainder
unsigned char n_bit;
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[]) // n_prom defined as 8x unsigned int (n_prom[8])
{
int cnt; // simple counter
unsigned int n_rem=0; // crc remainder
unsigned char n_bit;
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);
}
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 19
PIN CONFIGURATION
Pin
Nam
e
Type Function
1 VDD P Positive supply voltage
3 GND G Ground
7 SDA IO I
2
C data IO
8 SCL
SCL
I Serial data clock
2,4,5,6 NC
DEVICE PACKAGE OUTLINE
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 20
RECOMMENDED PAD LAYOUT
Pad layout for bottom side of the MS8607-02BA01 soldered onto printed circuit board.
SHIPPING PACKAGE
Reserved area:
Please do not route
tracks between pads
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 21
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.
MS8607-02BA01
PHT Combination Sensor
SENSOR SOLUTIONS ///MS8607-02BA01 06/2017 Page 22
ORDERING INFORMATION
Part Number / Art. Number
Product
Delivery Form
MS860702BA01-50 PHT Combination Sensor Module 5x3mm Tape & Reel
TE.com/sensorsolutions
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