Datasheet SHT1x (SHT10, SHT11, SHT15)
Humidity and Temperature Sensor
 Fully calibrated
 Digital output
 Low power consumption
 Excellent long term stability
 SMD type package – reflow solderable
Product Summary
Each SHT1x is individually calibrated in a precision
humidity chamber. The calibration coefficients areprogrammed into an OTP memory on the chip. These
coefficients are used to internally calibrate the signals
from the sensors. The 2-wire serial interface and internal
voltage regulation allows for easy and fast system
integration. The tiny size and low power consumption
makes SHT1x the ultimate choice for even the mostdemanding applications.

Dimensions

Sensor Chip

NC

NC

1

NC

3
4

A5Z

11

Material ContentsNCNC

2.5 ±0.1

2.2 MAX2NC

3.3 ±0.1

2.6 MAX

4.93 ±0.05

0.8 ±0.1

While the sensor is made of a CMOS chip the sensor
housing consists of an LCP cap with epoxy glob top on an
FR4 substrate. The device is fully RoHS and WEEE
compliant, thus it is free of Pb, Cd, Hg, Cr(6+), PBB and
PBDE.
Evaluation Kits

Figure 1: Drawing of SHT1x sensor packaging, dimensions in
mm (1mm = 0.039inch). Sensor label gives “11” for SHT11 as
an example. Contacts are assigned as follows: 1:GND, 2:DATA,
3:SCK, 4:VDD.

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SHT1x is supplied in a surface-mountable LCC (Leadless
Chip Carrier) which is approved for standard reflow
soldering processes. The same sensor is also available
with pins (SHT7x) or on flex print (SHTA1).

SHT1x V4 – for which this datasheet applies – features aversion 4 Silicon sensor chip. Besides the humidity andtemperature sensors the chip contains an amplifier, A/D
converter, OTP memory and a digital interface. V4 sensors
can be identified by the alpha-numeric traceability code on
the sensor cap – see example “A5Z” code on Figure 1.

0.6 ±0.1

sensor opening

5.2 ±0.2

4.2 ±0.1
1.27 ±0.05

1.5 ±0.2 2.0 ±0.1 1.5 ±0.1

1.83 ±0.05

7.47 ±0.05

0.95 ±0.1

SHT1x (including SHT10, SHT11 and SHT15) is
Sensirion’s family of surface mountable relative humidity
and temperature sensors. The sensors integrate sensor
elements plus signal processing on a tiny foot print andprovide a fully calibrated digital output. A uniquecapacitive sensor element is used for measuring relative
humidity while temperature is measured by a band-gap
sensor. The applied CMOSens® technology guarantees
excellent reliability and long term stability. Both sensors
are seamlessly coupled to a 14bit analog to digitalconverter and a serial interface circuit. This results insuperior signal quality, a fast response time andinsensitivity to external disturbances (EMC).

For sensor trial measurements, for qualification of thesensor or even experimental application (data logging) of
the sensor there is an evaluation kit EK-H4 available
including SHT71 (same sensor chip as SHT1x) and 4
sensor channels, hard and software to interface with acomputer. For other evaluation kits please checkwww.sensirion.com/humidity.

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Datasheet SHT1x

Sensor Performance
Relative Humidity123
Parameter

Temperature45

Condition

min
0.4
8

Units
%RH
bit
%RH

Parameter3.0
see Figure 2%RH

Accuracy 2
SHT11

2.0
see Figure 2%RH

Accuracy 2
SHT15

Repeatability

0.1

%RH

Hysteresis
Non-linearity
linearized3
Response time  (63%)
Operating Range
Long term drift 4 normal

1
<<1
8

%RH
%RH
s

Resolution 1
typicalmaximaltypicalmaximaltypicalmaximalAccuracy 2
SHT10
Accuracy 2
SHT11

max
0.05
12

4.5
see Figure 2

0

100
< 0.5

%RH
%RH/yr

Accuracy 2
SHT10

± 2.5

±2

typ
0.01
14

see Figure 3
0.1
-40
-40
5

123.8
254.9
30
< 0.04

SHT11

± 1.5
± 1.0
± 0.5

SHT15

±0

°C
°C
°F
s
°C/yr

SHT10

± 2.0

SHT11

maximalResponse Time 6  (63%)
Long term drift±8±4

typicalmaximaltypicalmaximaltypicalmax Units
0.01 °C
14
bit
°C
0.5
see Figure 3°C0.4
see Figure 3°C0.3

Operating Range

± 3.0

SHT10

min
0.04
12

Repeatability

± 10

±6

Condition

Resolution 1

T (°C)RH (%RH)

Accuracy 2
SHT15

typ
0.05
12

SHT15

± 0.0
0

10

20

30 40 50 60 70
Relative Humidity (%RH)

80

90

100

-40

-20

0

20
40
60
Temperature (°C)

Figure 2: Maximal RH-tolerance at 25°C per sensor type.

Figure 3: Maximal T-tolerance per sensor type.

Electrical and General Items

Packaging Information

Parameter
Source Voltage
Power
Consumption 5
Communication
Storage

Conditionmin2.4

typ max Units
3.3
5.5
V
sleep
2
5
µW
measuring3
mW
average90µW
digital 2-wire interface, see Communication
10 – 50°C (0 – 125°C peak), 20 – 60%RH

Sensor Type
SHT10
SHT11

SHT15

Packaging
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel

Quantity
2000
100
400
2000
100
400

80

100

Order Number
1-100218-04
1-100051-04
1-100098-04
1-100524-04
1-100085-04
1-100093-04

This datasheet is subject to change and may beamended without prior notice.
1

The default measurement resolution of is 14bit for temperature and 12bit forhumidity. It can be reduced to 12/8bit by command to status register.
2 Accuracies are tested at Outgoing Quality Control at 25°C (77°F) and 3.3V.
Values exclude hysteresis and are applicable to non-condensing environments
only.
3 Time for reaching 63% of a step function, valid at 25°C and 1 m/s airflow.

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4

Value may be higher in environments with high contents of volatile organic
compounds. See Section 1.3 of Users Guide.
5 Values for VDD=3.3V at 25°C, average value at one 12bit measurement
per second.
6 Response time depends on heat capacity of and thermal resistance tosensor substrate.

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Users Guide SHT1x
1 Application Information

100
80

Max. Range

60
40
20

NormalRange

IMPORTANT: After soldering the devices should be storedat >75%RH for at least 12h to allow the polymer to rehydrate. Otherwise the sensor may read an offset thatslowly disappears if exposed to ambient conditions.
Alternatively the re-hydration process may be performed atambient conditions (>40%RH) during more than 5 days.
In no case, neither after manual nor reflow soldering, aboard wash shall be applied. Therefore it is strongly
recommended to use “no-clean” solder paste. In case of
application with exposure of the sensor to corrosive gases
or condensed water (i.e. environments with high relative
humidity) the soldering pads shall be sealed (e.g.
conformal coating) to prevent loose contacts or short cuts.
For the design of the SHT1x footprint it is recommended touse dimensions according to Figure 7. Sensor pads arecoated with 35µm Cu, 5µm Ni and 0.1µm Au.

0
0

20
40
60
Temperature (°C)

80

100

2.47

120

1.97

1.07

Figure 4: Operating Conditions

Ø0.60

7.47

1.2 Soldering instructions
For soldering SHT1x standard reflow soldering ovens may
be used. The sensor is qualified to withstand solderingprofile according to IPC/JEDEC J-STD-020D with peaktemperatures at 260°C during up to 40sec including Pbfree assembly in IR/Convection reflow ovens.

1.27 1.27 1.27

-20

1.38

-40

0.80

Relative Humidity (%)

1.1 Operating Conditions
Sensor works stable within recommended normal range –see Figure 4. Long term exposures to conditions outside
normal range, especially at humidity >80%RH, may
temporarily offset the RH signal (+3 %RH after 60h). After
return to normal range it will slowly return towards
calibration state by itself. See Section 1.4 “Reconditioning
Procedure” to accelerate eliminating the offset. Prolonged
exposure to extreme conditions may accelerate ageing.

Figure 6: Rear side electrodes of sensor, view from top side.

4.61

preheating

critical zone

Time

Figure 5: Soldering profile according to JEDEC standard. TP <=260°C and tP < 40sec for Pb-free assembly. TL < 220°C and tL <150sec. Ramp-up/down speeds shall be < 5°C/sec.

For soldering in Vapor Phase Reflow (VPR) ovens thepeak conditions are limited to TP < 233°C during tP <60sec and ramp-up/down speeds shall be limited to
10°C/sec. For manual soldering contact time must be
limited to 5 seconds at up to 350°C7.

7

233°C = 451°F, 260°C = 500°F, 350°C = 662°F

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1.8

3.48
7.08

1.27 1.27 1.27

No copper in this field

0.47

tL

TS (max)

0.8

Temperature

TL

7.50

tP

TP

1.8

Figure 7: Recommended footprint for SHT1x. Values in mm.

1.3 Storage Conditions and Handling Instructions
It is of great importance to understand that a humidity
sensor is not a normal electronic component and needs tobe handled with care. Chemical vapors at highconcentration in combination with long exposure times
may offset the sensor reading.
For these reasons it is recommended to store the sensors
in original packaging including the sealed ESD bag at

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Datasheet SHT1x

following conditions: Temperature shall be in the range of
10°C – 50°C (0 – 125°C for limited time) and humidity at
20 – 60%RH (sensors that are not stored in ESD bags).
For sensors that have been removed from the original
packaging we recommend to store them in ESD bags
made of metal-in PE-HD8.
In manufacturing and transport the sensors shall be
prevented of high concentration of chemical solvents andlong exposure times. Out-gassing of glues, adhesive tapes
and stickers or out-gassing packaging material such as
bubble foils, foams, etc. shall be avoided. Manufacturing
area shall be well ventilated.
For more detailed information please consult the
document “Handling Instructions” or contact Sensirion.
1.4 Reconditioning Procedure
As stated above extreme conditions or exposure to solvent
vapors may offset the sensor. The following reconditioning
procedure may bring the sensor back to calibration state:
Baking:Re-Hydration:

Furthermore, there are self-heating effects in case themeasurement frequency is too high. Please refer to
Section 3.3 for detailed information.
1.6 Light
The SHT1x is not light sensitive. Prolonged direct
exposure to sunshine or strong UV radiation may age thehousing.
1.7 Membranes
SHT1x does not contain a membrane at the sensor
opening. However, a membrane may be added to prevent
dirt and droplets from entering the housing and to protect
the sensor. It will also reduce peak concentrations ofchemical vapors. For optimal response times the air
volume behind the membrane must be kept minimal.
Sensirion recommends and supplies the SF1 filter cap for
optimal IP54 protection (for higher protection – i.e. IP67 SF1 must be sealed to the PCB with epoxy). Please
compare Figure 9.
membrane

100 – 105°C at < 5%RH for 10h
20 – 30°C at ~ 75%RH for 12h 9.

housing

1.5 Temperature Effects
Relative humidity reading strongly depends on
temperature. Therefore, it is essential to keep humidity
sensors at the same temperature as the air of which therelative humidity is to be measured. In case of testing or
qualification the reference sensor and test sensor mustshow equal temperature to allow for comparing humidity
readings.
If the SHT1x shares a PCB with electronic componentsthat produce heat it should be mounted in a way thatprevents heat transfer or keeps it as low as possible.
Measures to reduce heat transfer can be ventilation,
reduction of copper layers between the SHT1x and therest of the PCB or milling a slit into the PCB around thesensor (see Figure 8).

A5Z

11

Figure 8: Top view of example of mounted SHT1x with slits
milled into PCB to minimize heat transfer.

89For example, 3M antistatic bag, product “1910” with zipper .
75%RH can conveniently be generated with saturated NaCl solution.
100 – 105°C correspond to 212 – 221°F, 20 – 30°C correspond to 68 – 86°F

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o-ring

SHT1x
PCB
Melted plastic pin
Figure 9: Side view of SF1 filter cap mounted between PCB andhousing wall. Volume below membrane is kept minimal.

1.8 Materials Used for Sealing / Mounting
Many materials absorb humidity and will act as a buffer
increasing response times and hysteresis. Materials in thevicinity of the sensor must therefore be carefully chosen.
Recommended materials are: Any metals, LCP, POM(Delrin), PTFE (Teflon), PE, PEEK, PP, PB, PPS, PSU,
PVDF, PVF.
For sealing and gluing (use sparingly): Use high filled
epoxy for electronic packaging (e.g. glob top, underfill),and Silicone. Out-gassing of these materials may also
contaminate the SHT1x (see Section 1.3). Therefore try to
add the sensor as a last manufacturing step to theassembly, store the assembly well ventilated after
manufacturing or bake at >50°C for 24h to outgas
contaminants before packing.
1.9 Wiring Considerations and Signal Integrity
Carrying the SCK and DATA signal parallel and in close
proximity (e.g. in wires) for more than 10cm may result incross talk and loss of communication. This may be

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Datasheet SHT1x

resolved by routing VDD and/or GND between the twodata signals and/or using shielded cables. Furthermore,slowing down SCK frequency will possibly improve signal
integrity. Power supply pins (VDD, GND) must be
decoupled with a 100nF capacitor if wires are used.
Capacitor should be placed as close to the sensor as
possible. Please see the Application Note “ESD, Latch-up
and EMC” for more information.
1.10 ESD (Electrostatic Discharge)
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
100mA with Tamb = 80°C according to JEDEC78A. See
Application Note “ESD, Latch-up and EMC” for more
information.

2 Interface Specifications
Pin Name
Comment
1 GND Ground
2 DATA Serial Data, bidirectional
3 SCK Serial Clock, input only
4 VDD Source Voltage
NC NC Must be left unconnected

NC
1
2
3
4

NC
NC
NC

A5Z

NC

11

NC

Table 1: SHT1x pin assignment, NC remain floating.

2.1 Power Pins (VDD, GND)
The supply voltage of SHT1x must be in the range of 2.4 –5.5V, recommended supply voltage is 3.3V. Power supply
pins Supply Voltage (VDD) and Ground (GND) must be
decoupled with a 100 nF capacitor – see Figure 10.
The serial interface of the SHT1x is optimized for sensor
readout and effective power consumption. The sensor
cannot be addressed by I2C protocol; however, the sensor
can be connected to an I2C bus without interference withother devices connected to the bus. The controller mustswitch between the protocols.
VDD

GND

RP
10kΩ

SHT1x
MicroController(Master)

DATA
SCK

A5Z

11

VDD
100nF

2.2 Serial clock input (SCK)SCK is used to synchronize the communication between
microcontroller and SHT1x. Since the interface consists offully static logic there is no minimum SCK frequency.
2.3 Serial data (DATA)The DATA tri-state pin is used to transfer data in and outof the sensor. For sending a command to the sensor,
DATA is valid on the rising edge of the serial clock (SCK)and must remain stable while SCK is high. After the fallingedge of SCK the DATA value may be changed. For safe
communication DATA valid shall be extended TSU and THO
before the rising and after the falling edge of SCK,
respectively – see Figure 11. For reading data from thesensor, DATA is valid TV after SCK has gone low andremains valid until the next falling edge of SCK.
To avoid signal contention the microcontroller must only
drive DATA low. An external pull-up resistor (e.g. 10kΩ) is
required to pull the signal high – it should be noted thatpull-up resistors may be included in I/O circuits of
microcontrollers. See Table 2 for detailed I/O characteristicof the sensor.
2.4 Electrical Characteristics
The electrical characteristics such as power consumption,
low and high level input and output voltages depend on
the supply voltage. Table 2 gives electrical characteristics
of SHT1x with the assumption of 5V supply voltage if notstated otherwise.
Parameter
Conditions
min typ max Units
Power supply DC10
2.4 3.3 5.5Vmeasuring
0.55
1
mA
11
Supply current
average
2
28
µA
sleep
0.3 1.5 µA
Low level output
IOL < 4 mA
0
250 mV
voltageHigh level output
RP < 25 kΩ
90%
100% VDD
voltageLow level input
Negative going 0%
20% VDD
voltageHigh level input
Positive going 80%
100% VDD
voltage
Input current on pads
1
µA
on
4
mA
Output current
Tri-stated (off)10
20 µA
Table 2: SHT1x DC characteristics. RP stands for pull up
resistor, while IOL is low level output current.

(Slave)2.4 – 5.5V

GND

Figure 10: Typical application circuit, including pull up resistor
RP and decoupling of VDD and GND by a capacitor.

10 Recommended voltage supply for highest accuracy is 3.3V, due to sensor

calibration.
11 Minimum value with one measurement of 8bit resolution without OTP reload

per second. Typical value with one measurement of 12bit resolution persecond.

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Datasheet SHT1x

Absolute maximum ratings for VDD versus GND are +7V
and -0.3V. Exposure to absolute maximum rating
conditions for extended periods may affect the sensor
reliability (e.g. hot carrier degradation, oxide breakdown).
For proper communication with the sensor it is essential to
make sure that signal design is strictly within the limits
given in Table 3 and Figure 11.

3.2 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 andraising DATA again while SCK is still high – see Figure 12.
SCK

TSCK
TSCKH

TSCKL

TR

TF
80%

SCK

20%

TSU

20%

80%
20%

THO
DATA valid write

Figure 12: "Transmission Start" sequence

DATA valid read
TRO
TFO

TV

80%

DATA

20%

Figure 11: Timing Diagram, abbreviations are explained inTable 3. Bold DATA line is controlled by the sensor, plain DATA
line is controlled by the micro-controller. Note that DATA valid
read time is triggered by falling edge of anterior toggle.
Parameter
FSCK SCK Frequency

Conditionsmin

typ max Units

VDD > 4.5V

0

0.1

5

MHz

VDD < 4.5V

0

0.1

1

MHz

TSCKx SCK hi/low time100

TR/TF SCK rise/fall time

1

200

*

ns

OL = 5pF

3.5

10

20

ns

OL = 100pF

30

40

200

ns

TFO

DATA

80%

DATA fall timens

The subsequent command consists of three address bits
(only ‘000’ is supported) and five command bits. The
SHT1x indicates the proper reception of a command bypulling the DATA pin low (ACK bit) after the falling edge ofthe 8th SCK clock. The DATA line is released (and goeshigh) after the falling edge of the 9th SCK clock.
CommandReserved
Measure Temperature
Measure Relative Humidity
Read Status Register
Write Status Register
Reserved
Soft reset, resets the interface, clears thestatus register to default values. Wait minimum
11 ms before next command

Code
0000x
00011
00101
00111
00110
0101x-1110x
11110

TRO

DATA rise time

**

**

**

ns

Table 4: SHT1x list of commands

TV

DATA valid time200 250

***

ns

3.3

TSU

DATA setup time100 150

***

ns

THO

DATA hold time

10

****

ns

*

TR_max + TF_max = (FSCK)-1 – TSCKH – TSCKL**

TR0 is determined by the RP*Cbus time-constant at DATA line***

TV_max and TSU_max depend on external pull-up resistor (RP) and total bus
line capacitance (Cbus) at DATA line****

TH0_max < TV – max (TR0, TF0)

After issuing a measurement command (‘00000101’ forrelative humidity, ‘00000011’ for temperature) thecontroller has to wait for the measurement to complete.
This takes a maximum of 20/80/320 ms for a 8/12/14bit
measurement. The time varies with the speed of theinternal oscillator and can be lower by up to 30%. To
signal the completion of a measurement, the SHT1x pulls
data line low and enters Idle Mode. The controller must
wait for this Data Ready signal before restarting SCK toreadout the data. Measurement data is stored until
readout, therefore the controller can continue with othertasks and readout at its convenience.

15

Table 3: SHT1x I/O signal characteristics, OL stands for Output
Load, entities are displayed in Figure 11.

3 Communication with Sensor
3.1 Start up Sensor
As a first step the sensor is powered up to chosen supply
voltage VDD. The slew rate during power up shall not fall
below 1V/ms. After power-up the sensor needs 11ms to
get to Sleep State. No commands must be sent before
that time.
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Measurement of RH and T

Two bytes of measurement data and one byte of CRC
checksum (optional) will then be transmitted. The microcontroller 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 thefirst byte is not used).

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Datasheet SHT1x

Important: To keep self heating below 0.1°C, SHT1x
should not be active for more than 10% of the time – e.g.
maximum one measurement per second at 12bit accuracy
shall be made.

After the command Status Register Read or Status
Register Write – see Table 4 – the content of 8 bits of thestatus register may be read out or written. For thecommunication compare Figure 14 and Figure 15 – theassignation of the bits is displayed in Table 5.

3
2

2

Status Register

Status Register

ACK

ACK
Bit 7

0 0 0 0 0 1 1 1

ACK
Bit 7

TS

Figure 14: Status Register Write
Checksum

Figure 15: Status Register Read

80%

9

4-8

0 0 0 0 0 1 1 0

Examples of full communication cycle are displayed in
Figure 16 and Figure 17.

20%

Transmission Start

TS

80%

DATA

20%

0 0 0 Command

Wait for0 0
DATA ready

MSB

ACK

SCK 1

TS

3.4 Connection reset sequence
If communication with the device is lost the following signal
sequence will reset the serial interface: While leaving
DATA high, toggle SCK nine or more times – see Figure
13. 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.

ACK

3.6 Status Register
Some of the advanced functions of the SHT1x such as
selecting measurement resolution, end-of-battery notice,use of OTP reload or using the heater may be activated bysending a command to the status register. The following
section gives a brief overview of these features.

ACK
Bit 7

Communication terminates after the acknowledge bit of
the CRC data. If CRC-8 checksum is not used thecontroller may terminate the communication after themeasurement data LSB by keeping ACK high. The device
automatically returns to Sleep Mode after measurement
and communication are completed.

Transmission Start

LSB

Checksum

ACK

3.5 CRC Checksum calculation
The whole digital transmission is secured by an 8bit
checksum. It ensures that any wrong data can be detected
and eliminated. As described above this is an additionalfeature of which may be used or abandoned. Please
consult Application Note “CRC Checksum” for information
on how to calculate the CRC.

LSb
ACK

Figure 13: Connection Reset Sequence

Figure 16: Overview of Measurement Sequence. TS = Transmission Start, MSB = Most Significant Byte, LSB = Last
Significant Byte, LSb = Last Significant Bit.

Address = ‘000’
A2
A1 A0

C4

Command = ‘00101’
C3
C2 C1
C0

ACK

Measurement(80ms for 12bit)

A2

C4

C3

ACK

Sensor pulls DATA line low after
completion of measurement

SCK
DATA
Idle Bits
14
13

15

12

MSb
11

10

11

10

A1

A0

9

8

C2

C1

C0

12bit Humidity Data
ACK 7
6
5

4

3

2

1

LSb
0

Skip ACK to end transmission(if no CRC is used)

ACK

SCK
DATA

15

14

13

MSb
7

12

6

5

9

ACK

8

CRC-8 Checksum
4
3
2

1

7

LSb
0

ACK

0

ACK

6

5

4

Sleep (wait for next
measurement)

3

2

1

0

ACK

Transmission Start

SCK
DATA

7

6

5

4

3

2

1

Figure 17: Example RH measurement sequence for value “0000’0100“0011’0001” = 1073 = 35.50%RH (without temperaturecompensation). DATA valid times are given and referenced in boxes on DATA line. Bold DATA lines are controlled by sensor while plain
lines are controlled by the micro-controller.
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Datasheet SHT1xTable 5: Status Register Bits

Measurement resolution: The default measurement
resolution of 14bit (temperature) and 12bit (humidity) canbe reduced to 12 and 8bit. This is especially useful in highspeed or extreme low power applications.
End of Battery function detects and notifies VDD voltages
below 2.47V. Accuracy is 0.05V.
Heater: An on chip heating element can be addressed bywriting a command into status register. The heater may
increase the temperature of the sensor by 5 – 10°C12
beyond ambient temperature. The heater draws roughly
8mA @ 5V supply voltage.
For example the heater can be helpful for functionality
analysis: Humidity and temperature readings before andafter applying the heater are compared. Temperature shall
increase while relative humidity decreases at the sametime. Dew point shall remain the same.
Please note: The temperature reading will display thetemperature of the heated sensor element and notambient temperature. Furthermore, the sensor is not
qualified for continuous application of the heater.
OTP reload: With this operation the calibration data is
uploaded to the register before each measurement. Thismay be deactivated for reducing measurement time byabout 10ms.

4 Conversion of Signal Output
4.1 Relative Humidity
For compensating non-linearity of the humidity sensor –see Figure 18 – and for obtaining the full accuracy of thesensor it is recommended to convert the humidity readout
12 Corresponds to 9 – 18°F

www.sensirion.com(SORH) with the following formula with coefficients given in
Table 6:2

RH linear  c 1  c 2  SO RH  c 3  SO RH (%RH)
SORH
12 bit8 bit

c1-2.0468-2.0468c2
0.03670.5872c3-1.5955E-6-4.0845E-4

Table 6: V4 humidity conversion coefficients

The values given in Table 6 are optimized coefficients forV4 sensors. The parameter set for V3 sensors, which has
been proposed in earlier datasheets, still applies and isprovided by Sensirion upon request.
Values higher than 99% RH indicate fully saturated air andmust be processed and displayed as 100%RH13. Please
note that the humidity sensor has no significant voltage
dependency.
100%

Relative Humidity

Bit Type Description
Default
7
reserved0
End of Battery (low voltage
No default value,detection)
bit is only updated
6 R
X‘0’ for VDD > 2.47
after a‘1’ for VDD < 2.47
measurement
5
reserved
04
reserved
03
For Testing only, do not use 0
2 R/W Heater
0 off
1 R/W no reload from OTP
0 reload’1’ = 8bit RH / 12bit Temp.
12bit RH
resolution0 R/W
0’0’ = 12bit RH / 14bit Temp.
14bit Temp.
resolution

80%
60%
40%
20%
0%
0

500

1000

1500

2000

2500

3000

3500

SORH sensor readout (12bit)

Figure 18: Conversion from SORH to relative humidity

4.2 Temperature compensation of Humidity Signal
For temperatures significantly different from 25°C (~77°F)
the humidity signal requires temperature compensation.
The temperature correction corresponds roughly to
0.12%RH/°C @ 50%RH. Coefficients for the temperaturecompensation are given in Table 7.

RH true  TC  25  t 1  t 2  SO RH   RHlinear
SORH
12 bit
8 bit

t1
0.01
0.01

t2
0.000080.00128

Table 7: Temperature compensation coefficients14

4.3 Temperature
The band-gap PTAT (Proportional To Absolute
Temperature) temperature sensor is very linear by design.

13 If wetted excessively (strong condensation of water on sensor surface),

sensor output signal can drop below 100%RH (even below 0%RH in somecases), but the sensor will recover completely when water droplets
evaporate. The sensor is not damaged by water immersion or condensation.
14 Coefficients apply both to V3 as well as to V4 sensors.

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Datasheet SHT1x

Use the following formula to convert digital readout (SOT)
to temperature value, with coefficients given in Table 8:enough dwell time for the measurement shall be granted.
For detailed information please consult Application Note
“Qualification Guide”.

T  d1  d 2  SO T

The SHT1x sensor series were tested according to AECQ100 Rev. G qualification test method. Sensor
specifications are tested to prevail under the AEC-Q100
temperature grade 2 test conditions listed in Table 1016.
Sensor performance under other test conditions cannot be
guaranteed and is not part of the sensor specifications.
Especially, no guarantee can be given for sensor
performance in the field or for customer’s specificapplication.

VDD
5V
4V
3.5V
3V
2.5V

d1 (°C)
-40.1
-39.8
-39.7
-39.6
-39.4

d1 (°F)
-40.2
-39.6
-39.5
-39.3
-38.9

SOT
14bit
12bit

d2 (°C)0.01
0.04

d2 (°F)
0.018
0.072

Table 8: Temperature conversion coefficients15.

Please contact Sensirion for detailed information.

4.4 Dew Point
SHT1x is not measuring dew point directly, however dew
point can be derived from humidity and temperature
readings. Since humidity and temperature are bothmeasured on the same monolithic chip, the SHT1x allows
superb dew point measurements.

EnvironmentHTSL

For dew point (Td) calculations there are various formulas
to be applied, most of them quite complicated. For thetemperature range of -40 – 50°C the following
approximation provides good accuracy with parameters
given in Table 9: RH  m  Tln 100%  Tn  T
Td RH, T   Tn 
 RH  m  T
m  ln 100%  Tn  T
Temperature Range
Above water, 0 – 50°C
Above ice,
-40 – 0°C

Tn (°C)
243.12272.62Standard
125°C, 1000 hours

Results17
Withinspecifications
TC-50°C - 125°C, 1000 cycles WithinAcc. JESD22-A104-C
specifications
UHST
130°C / 85%RH / ≈2.3bar,
Within96h
specifications
THU
85°C / 85%RH, 1000h
Withinspecifications
ESD immunity MIL STD 883E, method 3015 Qualified(Human Body Model at ±2kV)
Latch-upforce current of ±100mA with Qualified
Tamb = 80°C, acc. JEDEC 17
Table 10: Qualification tests: HTSL = High Temperature Storage
Lifetime, TC = Temperature Cycles, UHST = Unbiased Highly
accelerated Stress Test, THB = Temperature Humidity Unbiased

m
17.62
22.46

Table 9: Parameters for dew point (Td) calculation.

Please note that “ln(…)” denotes the natural logarithm. For
RH and T the linearized and compensated values for
relative humidity and temperature shall be applied.
For more information on dew point calculation see
Application Note “Introduction to Humidity”.

5 Environmental Stability
If sensors are qualified for assemblies or devices, please
make sure that they experience same conditions as thereference sensor. It should be taken into account that
response times in assemblies may be longer, hence

6 Packaging
6.1 Packaging typeSHT1x are supplied in a surface mountable LCC(Leadless Chip Carrier) type package. The sensor housing
consists of a Liquid Crystal Polymer (LCP) cap with epoxy
glob top on a standard 0.8mm FR4 substrate. The device
is fully RoHS and WEEE compliant – it is free of Pb, Cd,
Hg, Cr(6+), PBB and PBDE.
Device size is 7.47 x 4.93 x 2.5 mm (0.29 x 0.19 x 0.1inch), see Figure 1, weight is 100 mg.
6.2 Traceability Information
All SHT1x are marked with an alphanumeric, three digit
code on the chip cap (for reference: V3 sensors werelabeled with numeric codes) – see “A5Z” on Figure 1. The
lot numbers allow full traceability through production,
16 Sensor operation temperature range is -40 to 105°C according to AEC-Q100

15 Temperature coefficients have slightly been adjusted compared to datasheet

SHTxx version 3.01. Coefficients apply to V3 as well as V4 sensors.

www.sensirion.com

temperature grade 2.
17 According to accuracy and long term drift specification given on Page 2.

Version 4.3 – May 2010

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Datasheet SHT1x

calibration and testing. No information can be derived fromthe code directly; respective data is stored at Sensirion
and is provided upon request.
Labels on the reels are displayed in Figures 19 and 20,
they both give traceability information.

Lot No.:Quantity:
RoHS:

6.3 Shipping Package
SHT1x are shipped in 12mm tape at 100pcs, 400pcs and2000pcs – for details see Figure 21 and Table 11. Reels
are individually labeled with barcode and human readablelabels.
Sensor Type
SHT10

XX0-NN-YRRRTTTTT
RRRR
Compliant

SHT11

Lot No.

SHT15
Figure 19: First label on reel: XX = Sensor Type (11 for SHT11),
NN = Chip Version (04 for V4), Y = last digit of year, RRR =number of sensors on reel divided by 10 (200 for 2000 units),
TTTTT = Traceability Code.

Packaging
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel

Quantity
2000
100
400
2000
100
400

Order Number
1-100218-04
1-100051-04
1-100098-04
1-100524-04
1-100085-04
1-100093-04

Table 11: Packaging types per sensor type.

Dimensions of packaging tape are given in Figure 21. All
tapes have a minimum of 480mm empty leader tape (firstpockets of the tape) and a minimum of 300mm empty
trailer tape (last pockets of the tape).
Ø1.50 MIN
1.00
0.30 ± 0.05

Device Type:

12.00

1-100PPP-NN

Description:

R0.3 MAX
11

A5Z

5.80

Humidity & Temperature Sensor
SHTxx
Part Order No. 1-100PPP-NN or Customer Number
Date of Delivery: DD.MM.YYYY
Order Code:46CCCC / 0Ø1.50 MIN

12.0 ± 0.3
5.50 ± 0.05
1.75 ± 0.10

2.00 ± 0.05

R0.5 TYP

2.80
8.20

Figure 20: Second label on reel: For Device Type and Part
Order Number please refer to Table 12, Delivery Date (alsoDate Code) is date of packaging of sensors (DD = day, MM =month, YYYY = year), CCCC = Sensirion order number.

www.sensirion.com

Figure 21: Tape configuration and unit orientation within tape,dimensions in mm (1mm = 0.039inch). The leader tape is at theright side of the figure while the trailer tape is to the left
(direction of unreeling).

Version 4.3 – May 2010

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Datasheet SHT1x

Revision History
Date
July 2008
September 2008
April 2009
May 2010

Version
4.0
4.1
4.2
4.3

Page(s)1 – 11
3, 4
2, 7
1 – 11

Changes
New release, rework of datasheet
Adjustment of normal operating range and recommendation for antistatic bag
Amended foot note 2, communication diagram updated (Figure 17).
Various errors corrected and additional information given (ask for change protocol).

Important Notices
Warning, Personal Injury
Do not use this product as safety or emergency stop devices or in
any other application where failure of the product could result inpersonal injury. Do not use this product for applications otherthan its intended and authorized use. Before installing, handling,using or servicing this product, please consult the data sheet andapplication notes. Failure to comply with these instructions could
result in death or serious injury.
If the Buyer shall purchase or use SENSIRION products for any
unintended or unauthorized application, Buyer shall defend, indemnify
and hold harmless SENSIRION and its officers, employees,
subsidiaries, affiliates and distributors against all claims, costs,
damages and expenses, and reasonable attorney fees arising out of,
directly or indirectly, any claim of personal injury or death associatedwith such unintended or unauthorized use, even if SENSIRION shall beallegedly negligent with respect to the design or the manufacture of the
product.
ESD Precautions
The inherent design of this component causes it to be sensitive toelectrostatic discharge (ESD). To prevent ESD-induced damage and/or
degradation, take customary and statutory ESD precautions whenhandling this product.
See application note “ESD, Latchup and EMC” for more information.
Warranty
SENSIRION warrants solely to the original purchaser of this product fora period of 12 months (one year) from the date of delivery that thisproduct shall be of the quality, material and workmanship defined in
SENSIRION’s published specifications of the product. Within such
period, if proven to be defective, SENSIRION shall repair and/or
replace this product, in SENSIRION’s discretion, free of charge to the
Buyer, provided that:
notice in writing describing the defects shall be given to
SENSIRION within fourteen (14) days after their appearance;such defects shall be found, to SENSIRION’s reasonablesatisfaction, to have arisen from SENSIRION’s faulty design,material, or workmanship;the defective product shall be returned to SENSIRION’s factory at
the Buyer’s expense; and
the warranty period for any repaired or replaced product shall belimited to the unexpired portion of the original period.
This warranty does not apply to any equipment which has not been
installed and used within the specifications recommended by
SENSIRION for the intended and proper use of the equipment.
EXCEPT FOR THE WARRANTIES EXPRESSLY SET FORTHHEREIN, SENSIRION MAKES NO WARRANTIES, EITHER EXPRESSOR IMPLIED, WITH RESPECT TO THE PRODUCT. ANY AND ALL
WARRANTIES, INCLUDING WITHOUT LIMITATION, WARRANTIESOF MERCHANTABILITY OR FITNESS FOR A PARTICULARPURPOSE, ARE EXPRESSLY EXCLUDED AND DECLINED.
SENSIRION is only liable for defects of this product arising under theconditions of operation provided for in the data sheet and proper use of
the goods. SENSIRION explicitly disclaims all warranties, express or
implied, for any period during which the goods are operated or stored
not in accordance with the technical specifications.
SENSIRION does not assume any liability arising out of any applicationor use of any product or circuit and specifically disclaims any and all
liability, including without limitation consequential or incidental
damages. All operating parameters, including without limitation
recommended parameters, must be validated for each customer’s
applications by customer’s technical experts. Recommended
parameters can and do vary in different applications.
SENSIRION reserves the right, without further notice, (i) to change theproduct specifications and/or the information in this document and (ii) toimprove reliability, functions and design of this product.


Copyright© 2009, SENSIRION.
CMOSens® is a trademark of Sensirion
All rights reserved

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phone:+86 755 8252 1501
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Find your local representative at: http://www.sensirion.com/reps

Version 4.3 – May 201011/11