ETC SHT15

SHT1x / SHT7x
Humidity & Temperature Sensor
SHT7x
Evaluation Kit
Available
SHT1x
- Relative humidity and temperature sensors
- Dew point
- Fully calibrated, digital output
- Excellent long-term stability
- No external components required
- Ultra low power consumption
- Surface mountable or 4-pin fully interchangeable
- Small size
- Automatic power down
SHT1x / SHT7x Product Summary
The SHTxx is a single chip relative humidity and
temperature multi sensor module comprising a calibrated
digital output. Application of industrial CMOS processes with
patented micro-machining (CMOSens® technology) ensures
highest reliability and excellent long term stability. The
device includes a capacitive polymer sensing element for
relative humidity and a bandgap temperature sensor. Both
are seamlessly coupled to a 14bit analog to digital converter
and a serial interface circuit on the same chip. This results in
superior signal quality, a fast response time and insensitivity
to external disturbances (EMC) at a very competitive price.
Each SHTxx is individually calibrated in a precision humidity
chamber with a chilled mirror hygrometer as reference. The
calibration coefficients are programmed into the OTP
memory. These coefficients are used internally during
measurements to calibrate the signals from the sensors.
The 2-wire serial interface and internal voltage regulation
allows easy and fast system integration. Its tiny size and low
power consumption makes it the ultimate choice for even
the most demanding applications.
The device is supplied in either a surface-mountable LCC
(Leadless Chip Carrier) or as a pluggable 4-pin single-in-line
type package. Customer specific packaging options may be
available on request.
Applications
Block Diagram
_ HVAC
_ Automotive
_ Consumer Goods
_ Weather Stations
_ Humidifiers
_ Dehumidifiers
1
SCK
DATA
D
i
-b
14
t
Ordering Information
A
Digital 2wire
Interface
&
CRC
generator
GND
Humidity Temperature
Part
accuracy accuracy [K] Package
Number
[%RH]
@ 25 °C
SHT11
±3.0
±0.4
SMD (LCC)
SHT15
±2.0
±0.3
SMD (LCC)
SHT71
±3.0
±0.4
4-pin single-in-line
SHT75
±1.8
±0.3
4-pin single-in-line
www.sensirion.com
Calibration
Memory
%RH
Sensor
Amplification
_ Test & Measurement
_ Data Logging
_ Automation
_ White Goods
_ Medical
Temp.
Sensor
Sensirion, Eggbühlstr. 14, 8052 Zürich, Switzerland, Tel: +41 1 306 40 00, Fax: +41 1 306 40 30
VDD
v2.02
SHT1x / SHT7x Relative Humidity & Temperature Sensor System
1
Sensor Performance Specifications
Parameter
Conditions Min. Typ. Max. Units
Humidity
Resolution (2)
0.5
8
Repeatability
Accuracy (1)
Uncertainty
Interchangeability
Nonlinearity
Range
Response time
linearized
raw data
linearized
1/e (63%)
slowly moving air
Hysteresis
Long term stability
Fully interchangeable
%RH
±3
<<1
%RH
0
100 %RH
4
s
%RH
%RH/yr
°C
°F
bit
°C
°F
1/e (63%)
0.04 0.01 0.01
0.07 0.02 0.02
12 14
14
±0.1
±0.2
see figure 1
-40
123.8
-40
254.9
5
30
Accuracy
Range
°C
°F
s
±3
SHT11/71
±2
SHT15
±1
SHT75
0 10 20 30 40 50 60 70 80 90 100
Temperature accuracy
±3 °C
±2 °C
%RH
±5.4 °F
±3.6 °F
SHT11/71
±1 °C
±1.8 °F
SHT15/75
0 °C
0 °F
-40°C
-40°F
±5 °C
0°C
32°F
40°C
104°F
80°C
176°F
120°C
248°F
Dewpoint accuracy @ 25 °C (typical)
±9.0 °F
±4 °C
±7.2 °F
±3 °C
±5.4 °F
±2 °C SHT15
±1 °C
±0 °C
SHT11/71
SHT75
±3.6 °F
±1.8 °F
0 10 20 30 40 50 60 70 80 90 100
Sensor Performance Specifications
Figure 1
2
Relative Humidity absolute accuracy
±4
±0
±1
< 0.5
Repeatability
Table 1
%RH
bit
%RH
typical
Temperature
Resolution (2)
Response Time
0.03 0.03
12
12
±0.1
see figure 1
%RH
±5
%RH
Rel. Humidity, Temperature and Dewpoint accuracies
Interface Specifications
Vdd
2.2.1 Serial clock input (SCK)
GND
uC
DATA
(master)
SCK
The SCK is used to synchronize the communication between
a microcontroller and the SHTxx. Since the interface
consists of fully static logic there is no minimum SCK
frequency.
SHT1x
(slave)
Vdd 2.4 - 5.5V
Figure 2
Typical application circuit
2.2.2 Serial data (DATA)
2.1 Power Pins
The SHTxx requires a voltage supply between 2.4 and 5.5 V.
After powerup the device needs 11ms to reach its “sleep”
state. No commands should be sent before that time.
Power supply pins (VDD, GND) may be decoupled with a
100 nF capacitor.
2.2 Serial Interface (Bidirectional 2-wire)
The serial interface of the SHTxx is optimized for sensor
readout and power consumption and is not compatible with
I2C interfaces, see FAQ for details.
The DATA tristate pin is used to transfer data in and out of
the device. DATA changes after the falling edge and is
valid on the rising edge of the serial clock SCK. During
transmission the DATA line must remain stable while SCK is
high. To avoid signal contention the microcontroller should
only drive DATA low. An external pull-up resistor (e.g. 10 kΩ )
is required to pull the signal high. (See Figure 2) Pull-up
resistors are often included in I/O circuits of microcontrollers.
See Table 5 for detailed IO characteristics.
(1) Each
(2) The
SHTxx is tested to be fully within RH accuracy specifications at 25 °C (77 °F) and 48 °C (118.4 °F)
default measurement resolution of 14bit (temperature) and 12bit (humidity) can be reduced to 12 and 8 bit through the status register.
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v2.02 July 2004
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SHT1x / SHT7x Relative Humidity & Temperature Sensor System
therefore the controller can continue with other tasks and
readout as convenient.
2.2.3 Sending a command
To initiate a transmission, a “Transmission Start” sequence
has to be issued. It consists of a lowering of the DATA line
while SCK is high, followed by a low pulse on SCK and
raising DATA again while SCK is still high.
Two bytes of measurement data and one byte of CRC
checksum will then be transmitted. The uC must
acknowledge each byte by pulling the DATA line low. All
values are MSB first, right justified. (e.g. the 5th SCK is MSB
for a 12bit value, for a 8bit result the first byte is not used).
Communication terminates after the acknowledge bit of the
CRC data. If CRC-8 checksum is not used the controller may
terminate the communication after the measurement data
LSB by keeping ack high.
The device automatically returns to sleep mode after the
measurement and communication have ended.
DATA
SCK
Figure 3
"Transmission Start" sequence
The subsequent command consists of three address bits
(only “000” is currently supported) and five command bits.
The SHTxx indicates the proper reception of a command by
pulling the DATA pin low (ACK bit) after the falling edge of
the 8th SCK clock. The DATA line is released (and goes
high) after the falling edge of the 9th SCK clock.
Command
Reserved
Measure Temperature
Measure Humidity
Read Status Register
Write Status Register
Reserved
Soft reset, resets the interface, clears the
status register to default values
wait minimum 11 ms before next command
Table 2
Warning: To keep self heating below 0.1 °C the SHTxx
should not be active for more than 10% of the time
(e.g. max. 2 measurements / second for 12bit accuracy).
Code
0000x
00011
00101
00111
00110
0101x-1110x
11110
2.2.5 Connection reset sequence
If communication with the device is lost the following signal
sequence will reset its serial interface:
While leaving DATA high, toggle SCK 9 or more times. This
must be followed by a “Transmission Start” sequence
preceding the next command. This sequence resets the
interface only. The status register preserves its content.
DATA
Transmission Start
SHTxx list of commands
2.2.4 Measurement sequence (RH and T)
SCK
After issuing a measurement command (‘00000101’ for RH,
‘00000011’ for Temperature) the controller has to wait for the
measurement to complete. This takes approximately
11/55/210 ms for a 8/12/14bit measurement. The exact time
varies by up to ±15% with the speed of the internal oscillator.
To signal the completion of a measurement, the SHTxx pulls
down the data line and enters idle mode. The controller must
wait for this “data ready” signal before restarting SCK to
readout the data. Measurement data is stored until readout,
Figure 4
Transmission Start
Address=’000’
1
2
4 -8
3
Connection reset sequence
2.2.6 CRC-8 Checksum calculation
The whole digital transmission is secured by a 8 bit
checksum. It ensures that any wrong data can be detected
and eliminated.
Please consult application note “CRC-8 Checksum
Calculation” for information on how to calculate the CRC.
Bold = SHT1xx controls DATA line
Plain = uC controls DATA line
Command=’00101’
Measurement
~55ms for 12 bit
~11ms for 8 bit
DATA
a2
a0
a1
C4
9
C3
C2
C1
C0
ack
SCK
Measurement is finished when the
SHTxx pulls down the DATA line
Skip acknowledge to end transmission
(if no CRC is used)
12 bit humidity data
DATA
low
low
low
low
11
10
9
8
ack
7
6
5
4
3
2
1
0
ack
SCK
MSB
LSB
CRC-8 Checksum
wait for next measurement
DATA
7
6
5
4
3
2
1
ack
0
SCK
MSB
Figure 5
Transmission Start
Skip acknowledge to
end transmission
LSB
Example RH measurement sequence for value “0000’1001 ’ 0011’0001”= 2353 = 75.79 %RH (without temperature compensation)
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SHT1x / SHT7x Relative Humidity & Temperature Sensor System
LSB
ack
MSB
ack
0
LSB
0 0 0
ack
ack
TS
wait for data ready
Checksum
Command
Figure 6
Overview of Measurement Sequence (TS = Transmission Start)
2.3 Status Register
Status
Reg
ack
0 00 0 01 1 0
ack
Bit 7
TS
Some of the advanced functions of the SHTxx are available
through the status register. The following section gives a
brief overview of these features. A more detailed description
is available in the application note “Status Register”
2.4 Electrical Characteristics(1)
Command
VDD=5V, Temperature = 25 °C unless otherwise noted
Status
Reg
Checksum
Parameter
Power supply DC
Supply current
ack
000 0011 1
ack
Bit 7
Status Register Write
ack
Bit 7
TS
Figure 7
Command
Figure 8
Status Register Read
Bit Type
7
6
R
Description
reserved
End of Battery (low voltage detection)
‘0’ for Vdd > 2.47
‘1’ for Vdd < 2.47
5
4
3
2
1
0
reserved
reserved
For Testing only, do not use
Heater
no reload from OTP
’1’ = 8bit RH / 12bit Temperature resolution
’0’ = 12bit RH / 14bit Temperature resolution
R/W
R/W
R/W
Table 3
after switching on the heater, proper functionality of both
sensors can be verified.
• In high (>95 %RH) RH environments heating the sensor
element will prevent condensation, improve response
time and accuracy
Warning: While heated the SHTxx will show higher
temperatures and a lower relative humidity than with no
heating.
Default
0
X No default value,
bit
is
only
updated after a
measurement
0
0
0
0 off
0 reload
0 12bit RH
14bit Temp.
Status Register Bits
2.3.1 Measurement resolution
The default measurement resolution of 14bit (temperature)
and 12bit (humidity) can be reduced to 12 and 8bit. This is
especially useful in high speed or extreme low power
applications.
2.3.2 End of Battery
Min. Typ.
2.4
5
measuring
550
average
2(2) 28(3)
sleep
0.3
Low level output voltage
0
High level output voltage
75%
Low level input voltage Negative going 0
High level input voltage Positive going 80%
Input current on pads
Output peak current
on
Tristated (off)
10
Table 4
Conditions
Min Typ. Max.
FSCK
VDD > 4.5 V
10
VDD < 4.5 V
1
TRFO DATA fall time
Output load 5 pF
3.5 10 20
Output load 100 pF 30 40 200
TCLx SCK hi/low time
100
TV
DATA valid time
250
TSU DATA set up time
100
THO DATA hold time
0 10
TR/TF SCK rise/fall time
200
Table 5
An on chip heating element can be switched on. It will
increase the temperature of the sensor by 5-15 °C (9-27 °F).
Power consumption will increase by ~8 mA @ 5 V.
Applications:
By comparing temperature and humidity values before and
(3)
Unit
MHz
MHz
ns
ns
ns
ns
ns
ns
ns
SHTxx I/O Signals Characteristics
TR
TCLH
TF
FSCK
SCK
2.3.3 Heater
(2)
Max. Units
5.5 V
µA
µA
1 µA
20% Vdd
100% Vdd
20% Vdd
100% Vdd
1 µA
4 mA
µA
SHTxx DC Characteristics
Parameter
SCK frequency
The “End of Battery” function detects VDD voltages below
2.47 V. Accuracy is ±0.05 V
1)
Conditions
TV
TSU
THO
DATA
Figure 9
Timing Diagram
Parameters are periodically sampled and not 100% tested
With one measurement of 8 bit accuracy without OTP reload per second
With one measurement of 12bit accuracy per second
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SHT1x / SHT7x Relative Humidity & Temperature Sensor System
3
Converting Output to Physical Values
3.1 Relative Humidity
3.2 Temperature
To compensate for the non-linearity of the humidity sensor
and to obtain the full accuracy it is recommended to convert
the readout with the following formula1:
RHlinear = c 1 + c 2 • SORH + c 3 • SORH 2
The bandgap PTAT (Proportional To Absolute Temperature)
temperature sensor is very linear by design. Use the
following formula to convert from digital readout to
temperature:
SORH
c1
c2
c3
12 bit
-4
0.0405
-2.8 * 10-6
8 bit
-4
0.648
-7.2 * 10-4
Table 6 Humidity conversion coefficients
For simplified, less computation intense conversion formulas
see application note “RH and Temperature Non-Linearity
Compensation”.
The humidity sensor has no significant voltage dependency.
Temperature = d1 + d 2 • SOT
VDD
5V
4V
3.5V
3V
2.5V
Table 8
d1 [°C]
d1 [°F]
SOT
d2 [°C] d2 [°F]
-40.00
-40.00
14bit
0.01
0.018
-39.75
-39.50
12bit
0.04
0.072
-39.66
-39.35
-39.60
-39.28
-39.55
-39.23
Temperature conversion coefficients
&
For improved accuracies in extreme temperatures with more
computation intense conversion formulas see application
note “RH and Temperature Non-Linearity Compensation”.
$
3.3 Dewpoint
%RH
Since humidity and temperature are both measured on the
same monolithic chip, the SHTxx allows superb dewpoint
measurements. See application note “Dewpoint calculation”
for more.
"
#
#
#
SORH sensor readout (12bit)
!
Figure 10 Conversion from SORH to relative humidity
3.1.1 Humidity Sensor RH/Temperature compensation
For temperatures significantly different from 25 °C (~77 °F)
the temperature coefficient of the RH sensor should be
considered:
RHtrue = (T°C - 25) • (t1 + t 2 • SORH ) + RHlinear
SORH
t1
t2
12 bit
0.01
0.00008
8 bit
0.01
0.00128
Table 7 Temperature compensation coefficients
This equals ~0.12 %RH / °C @ 50 %RH
1
Where SORH is the sensor output for relative humidity
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SHT1x / SHT7x Relative Humidity & Temperature Sensor System
4
Applications Information
4.1 Operating and Storage Conditions
100
4.6 Light
[%RH]
Maximum operating
conditions
80
60
4.7
Normal operating
conditions
40
20
0
-40
[°C]
-20
0
20
40
The SHTxx is not light sensitive. Prolonged direct exposure
to sunshine or strong UV radiation may age the housing.
60
80
100 120
Figure 11 Recommended operating conditions
Conditions outside the recommended range may temporarily
offset the RH signal up to ±3 %RH. After return to normal
conditions it will slowly return towards calibration state by
itself. See 4.3 “Reconditioning Procedure” to accelerate this
process. Prolonged exposure to extreme conditions may
accelerate ageing.
4.2 Exposure to Chemicals
Materials Used for Sealing / Mounting
Many materials absorb humidity and will act as a buffer,
increasing response times and hysteresis. Materials in the
vicinity of the sensor must therefore be carefully chosen.
Recommended materials are: All Metals, LCP, POM (Delrin),
PTFE (Teflon), PE, PEEK, PP, PB, PPS, PSU, PVDF, PVF
For sealing and gluing (use sparingly): High filled epoxy for
electronic packaging (e.g. glob top, underfill), and Silicone.
Outgassing of these materials may also contaminate the
SHTxx (cf. 4.2). Store well ventilated after manufacturing or
bake at 50°C for 24h to outgas contaminants before
packing.
4.8 Wiring Considerations and Signal Integrity
Chemical vapors may interfere with the polymer layers used
for capacitive humidity sensors. The diffusion of chemicals
into the polymer may cause a shift in both offset and
sensitivity. In a clean environment the contaminants will
slowly outgas. The reconditioning procedure described
below will accelerate this process. High levels of pollutants
may cause permanent damage to the sensing polymer.
Carrying the SCK and DATA signal parallel and in close
proximity (e.g. in wires) for more than 10cm may result in
cross talk and loss of communication. This may be resolved
by routing VDD and/or GND between the two data signals.
Please see the application note “ESD, Latchup and EMC” for
more information.
Power supply pins (VDD, GND) should be decoupled with a
100 nF capacitor if wires are used.
4.3 Reconditioning Procedure
4.9 Qualifications
The following reconditioning procedure will bring the sensor
back to calibration state after exposure to extreme conditions
or chemical vapors.
80-90 °C (176-194°F) at < 5 %RH for 24h (baking) followed by
20-30 °C (70-90°F) at > 74 %RH for 48h (re-hydration)
Extensive tests were performed in various environments.
Please contact SENSIRION for detailed information.
4.4 Temperature Effects
Environment
Norm
Results(1)
Temperature
Cycles
HAST
Pressure Cooker
High Temperature
and Humidity
Salt Atmosphere
Condensing Air
Freezing cycles
fully submerged
Various Automotive
Chemicals
JESD22-A104-B
-40 °C / 125 °C, 1000 cy
JESD22-A110-B
2.3 bar 125 °C 85 %RH
JESD22-A101-B
85 °C 85 %RH 1250h
DIN-50021ss
-20 / +90 °C, 100 cy
30min dwell time
DIN 72300-5
Within
Specifications
Reversible shift
by +2 %RH
Reversible shift
by +2 %RH
Within Spec.
Within Spec.
Reversible shift
by +2 %RH
Within
Specifications
The relative humidity of a gas strongly depends on its
temperature. It is therefore essential to keep humidity
sensors at the same temperature as the air of which the
relative humidity is to be measured.
If the SHTxx shares a PCB with electronic components that
give off heat it should be mounted far away and below the
heat source and the housing must remain well ventilated.
To reduce heat conduction copper layers between the
SHT1x and the rest of the PCB should be minimized and a
slit may be milled in between (see figure 13).
Table 9
4.5 Membranes
4.10 ESD (Electrostatic Discharge)
A membrane may be used to prevent dirt from entering the
housing and to protect the sensor. It will also reduce peak
concentrations of chemical vapors. For optimal response
times air volume behind the membrane must be kept to a
minimum. For the SHT1x package Sensirion recommends
the SF1 filter cap for optimal IP67 protection.
ESD immunity is qualified according to MIL STD 883E,
method 3015 (Human Body Model at ±2 kV)).
Latch-up immunity is provided at a force current of ±100 mA
with Tamb = 80 °C according to JEDEC 17. See application
note “ESD, Latchup and EMC” for more information.
(1)
Qualification tests (excerpt)
The temperature sensor passed all tests without any detectable drift. Package and electronics also passed 100%
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SHT1x / SHT7x Relative Humidity & Temperature Sensor System
5
Package Information
5.1 SHT1x (surface mountable)
Pin
1
2
3
4
Name
GND
DATA
SCK
VDD
NC
Comment
Ground
Serial data, bidirectional
Serial clock, input
Supply 2.4 - 5.5 V
Remaining pins must be left unconnected
Table 10 SHT1x Pin Description
For manual soldering contact time must be limited to 5
seconds at up to 350 °C.
After soldering the devices should be stored at >74 %RH for
at least 24h to allow the polymer to rehydrate.
Please consult the application note “Soldering procedure” for
more information.
5.1.4 Mounting Examples
5.1.1 Package type
The SHT1x is supplied in a surface-mountable LCC
(Leadless Chip Carrier) type package. The sensors housing
consists of a Liquid Crystal Polymer (LCP) cap with epoxy
glob top on a standard 0.8 mm FR4 substrate. The device is
free of lead, Cd and Hg.
Device size is 7.42 x 4.88 x 2.5 mm (0.29 x 0.19 x 0.1 inch)
Weight 100 mg
The production date is printed onto the cap in white numbers
in the form wwy. e.g. ”351” = week 35, 2001.
5.1.2 Delivery Conditions
The SHT1x are shipped in 12mm tape at 100pcs or 400pcs..
Reels are individually labelled with barcode and human
readable labels. The Lot numbers allow full traceability
through production, calibration and test.
Slit to minimize heat
transfer from the PCB
Figure 13 SHT1x PCB Mounting example
The SF1 membrane filter cap is available for optimal IP67
protection. When mounted through a housing the interior can
be protected from the environment while still allowing high
quality humidity measurements (see example below).
o-ring
housing
housing
2.8mm
Filtercap
SHT1x
Components
Trailer Tape
300mm minimum
Carrier Tape
Cover Tape
Leader Tape
480mm minimum
PCB
Figure 12 Tape configuration and unit orientation
melted plastic pin
5.1.3 Soldering Information
Standard reflow soldering ovens may be used. For details
please see application note "soldering procedure".
Top View
1.15
(0.04)
1.9
(0.07)
Figure 14 SF1 IP67 filter cap mounting example
Side View
Recommended PCB Footprint
1.49
(0.06)
2.44
(0.1)
4.88 (0.19)
1.8
(0.07)
actual size
3.48 (0.137)
7.08 (0.278)
1.27 1.27 1.27
(0.05)
NC
No copper inside this field
4
0.8
(0.03)
NC
0.47
(0.018)
3
4.61 (0.2)
NC
2.5
(0.1)
2
0.8
(0.03)
NC
0.6
(0.02)
1
5.22 (0.2)
NC
3.99 (0.16)
7.42 (0.29)
6.88 (0.27)
1.81 1.27
(0.07) (0.05)
sensor opening
NC
1.8
(0.07)
Figure 15 SHT1x drawing and footprint dimensions in mm (inch)
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SHT1x / SHT7x Relative Humidity & Temperature Sensor System
5.2 SHT7x (4-pin single-in-line)
Name
SCK
VDD
GND
DATA
Comment
Serial clock input
Supply 2.4 - 5.5 V
Ground
Serial data bidirectional
0.4
(0.02)
Pin
1
2
3
4
3.1
(0.12)
2.2
(0.09)
3.7
(0.15)
Table 11 SHT7x Pin Description
3.7
(0.15)
1.2
(0.05)
2
3
4
~6
(~0.24)
1
0.6
(0.024)
3.4
(0.13)
The device is supplied in a single-in-line pin type package.
The sensor housing consists of a Liquid Crystal Polymer
(LCP) cap with epoxy glob top on a standard 0.6 mm FR4
substrate. The device is Cd and Hg free.
The sensor head is connected to the pins by a small bridge
to minimize heat conduction and response times. The gold
plated back side of the sensor head is connected to the GND
pin.
A 100nF capacitor is mounted on the back side between
VDD and GND.
All pins are gold plated to avoid corrosion. They can be
soldered or mate with most 1.27 mm (0.05’’) sockets
e.g.: Preci-dip / Mill-Max 851-93-004-20-001 or similar
Total weight: 168 mg, weight of sensor head: 73 mg
13.5
(0.53)
5.2.1 Package type1
The production date is printed onto the cap in white numbers
in the form wwy. e.g. ”351” = week 35, 2001.
5.2.2 Delivery Conditions
The SHT7x are shipped in 32 mm tape. These reeled parts
in standard option are shipped with 500 units per 13 inch
diameter reel. Reels are individually labelled with barcode
and human readable labels.
0.46
1.27
(0.018) 5.08 (0.05)
(0.2)
0.2
(0.01)
2
(0.08)
Figure 17 SHT7x dimensions in mm (inch)
Carrier Tape
Cover Tape
Trailer Tape
300mm minimum
Components
Leader Tape
500mm minimum
Figure 16 Tape configuration and unit orientation
5.2.3 Soldering Information2
Standard wave SHT7x soldering ovens may be used at
maximum 235 °C for 20 seconds.
For manual soldering contact time must be limited to 5
seconds at up to 350 °C.
After wave soldering the devices should be stored at
>74 %RH for at least 24 h to allow the polymer to rehydrate.
Please consult the application note “Soldering procedure” for
more information.
Other packaging options may be available on request.
For maximum accuracy do not solder SHT75!
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SHT1x / SHT7x Relative Humidity & Temperature Sensor System
6
Revision history
Date
February 2002
June 2002
March 2003
July 2004
Version
Page(s) Changes
Preliminary 1-9
First public release
Preliminary
Added SHT7x information
Final v2.0 1-9
Major remake, added application information etc.
Various small modifications
V2.01
1-9
Typos, Graph labeling
V2.02
1-9
Improved specifications, added SF1 information, improved wording
The latest version of this document and all application notes can be found at:
www.sensirion.com/en/download/humiditysensor/SHT1x_SHT7x.htm
7
Important Notices
7.1 Warning, personal injury
7.3 Warranty
Do not use this product as safety or emergency stop
devices or in any other application where failure of the
product could result in personal injury. Failure to
comply with these instructions could result in death or
serious injury.
SENSIRION AG makes no warranty, representation or guarantee
regarding the suitability of its product for any particular purpose,
nor does SENSIRION AG assume any liability arising out of the
application or use of any product or circuit and specifically
disclaims any and all liability, including without limitation
consequential or incidental damages. “Typical” parameters can
and do vary in different applications. All operating parameters,
including “Typical” must be validated for each customer
applications by customer’s technical experts.
Should buyer purchase or use SENSIRION AG products for any
such unintended or unauthorized application, Buyer shall
indemnify and hold SENSIRION AG and its officers, employees,
subsidiaries, affiliates and distributors harmless against all claims,
costs, damages and expenses, and reasonable attorney fees
arising out of, directly or indirectly, any claim of personal injury or
death associated with such unintended or unauthorized use, even
if such claim alleges that SENSIRION AG was negligent regarding
the design or manufacture of the part.
7.2 ESD Precautions
The inherent design of this component causes it to be sensitive to
electrostatic discharge (ESD). To prevent ESD-induced damage
and/or degradation, take normal ESD precautions when handling
this product.
See application note “ESD, Latchup and EMC” for more
information.
SENSIRION AG reserves the right, without further notice, to
change the product specifications and/or information in this
document and to improve reliability, functions and design.
Copyright© 2001-2004, SENSIRION AG.
All rights reserved.
Headquarters and Sales Office
SENSIRION AG
Eggbühlstr. 14
P.O. Box
CH-8052 Zürich
Switzerland
Phone:
+ 41 (0)44 306 40 00
Fax:
+ 41 (0)44 306 40 30
e-mail:
[email protected]
http://www.sensirion.com/
Sensirion humidity sensors are available from:
find your local representative at:
www.sensirion.com/reps
www.sensirion.com
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