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Legal notice© Sensirion AG

SHT21

±2% Digital humidity and temperature sensor

The digital SHT2x humidity sensor series is used in high volumes in a wide variety of applications and has today become the de facto industry standard. The SHT2x series consists of a low-cost version with the SHT20 humidity sensor, a standard version with the SHT21 humidity sensor, and a high-end version with the SHT25 humidity sensor. The open cavity mold package - which encapsulates the complete chip except for the humidity sensor area - protects the capacitive humidity sensor against external impact and facilitates excellent long-term stability. The SHT2x sensors are available both in large and small volumes. Embedded in a reflow solderable dual-flat no-leads (DFN) package of 3 × 3 × 1.1 mm³, the SHT2x provides calibrated, linearized sensor signals in digital, I²C format. The SHT2x humidity sensor series contains a capacitive-type humidity sensor, a band-gap temperature sensor, and specialized analog and digital integrated circuits – all on a single CMOSens® chip. This yields superior sensor performance in terms of accuracy and stability as well as minimal power consumption. Every sensor is individually calibrated and tested. Lot identification is printed on the sensor and an electronic identification code is stored on the chip – which can be read out on command. Furthermore, the resolution of the SHT2x humidity sensor can be changed on command (8/12 bit up to 12/14 bit for RH/T) and a checksum helps to improve communication reliability. With this set of features and its proven reliability and long-term stability, the SHT2x humidity sensor series offers an outstanding price-performance ratio. To test a humidity sensor from the SHT2x series, two evaluation kits, EK-H4 and EK-H5, are available.
See inventoryDistributor listContact sales

Successor product

NameDescriptionSeriesCategory
SHT41±1.8% / max. ±2.5% RH Digital humidity and temperature sensorSHT4xHumidity

SHT41

±1.8% / max. ±2.5% RH Digital humidity and temperature sensor

SHT4x

Humidity

Specification

Humidity
Typ. relative humidity accuracy
2
2%RH
Operating relative humidity range
0 - 100
0 - 100%RH
Response time (τ63%)
8
8s
Calibration certificate
Factory calibration
Factory calibration
Temperature
Typ. temperature accuracy
0.3
0.3°C
Response time (τ63%)
5
5s
Generic
Supply voltage
2.1 - 3.6
2.1 - 3.6V
Average supply current
300
300uA
Max. supply current
330
330uA
Operating temperature range [°C]
-40 - 125
-40 - 125°C
Interfaces
I²C
I²C
Size (LxWxH)
3 x 3 x 1.1
3 x 3 x 1.1mm
Packaging size
400, 1500, 5000
400, 1500, 5000pcs (T&R)

Downloads

Datasheet SHT21

10/2022

File

408.5 KB

Datasheet10/2022PDF408.5 KB
SHT21 interfacing with EnOcean STM300

09/2011

File

300.9 KB

Application note09/2011PDF300.9 KB
SHT21 using Telran

10/2011

File

452.2 KB

Application note10/2011PDF452.2 KB
Sample code SHT21

File

18.5 KB

SoftwareZIP18.5 KB
CRC cecksum calculation SHT2x

12/2011

File

137.0 KB

Application note12/2011PDF137.0 KB
Embedding SHT2x in 5V supply

06/2012

File

186.9 KB

Application note06/2012PDF186.9 KB
Handling instructions SHT

06/2025

File

470.2 KB

Application note06/2025PDF470.2 KB
Humidity at a glance

05/2025

File

204.6 KB

Application note05/2025PDF204.6 KB
Introduction to humidity

08/2009

File

224.9 KB

Application note08/2009PDF224.9 KB
Specification statement and testing humidity sensors

04/2021

File

306.8 KB

Application note04/2021PDF306.8 KB
Testing at ambient conditions SHT

10/2022

File

443.0 KB

Application note10/2022PDF443.0 KB
SEK-ControlCenter (all devices)

Link

SoftwareLink
STEP file SHT2x

File

151.4 KB

Drawings/CADZIP151.4 KB
Calibration certification SHT/STS

08/2021

File

110.4 KB

Certificate08/2021PDF110.4 KB
REACH and RoHS declaration SHT/STS

01/2025

File

109.5 KB

Certificate01/2025PDF109.5 KB

Accessories

NameDescriptionSeriesCategory
SF2 filter capFilter cap for SHT2x to SHT4x humidity and temperature sensorsSFx filter capHumidity

SF2 filter cap

Filter cap for SHT2x to SHT4x humidity and temperature sensors

SFx filter cap

Humidity
NRND

Smart sensors for your application

Sensirion's sensor solutions are used in a wide range of applications and markets. Our reliable environmental and flow sensors improve energy efficiency, increase health and ensure safety and comfort.

  • All products
  • Humidity
  • SHT2x

Latest Humidity sensors

Explore
SHT43 humidity and temperature sensor demonstrator
Upcoming

SHT43 DemoBoard

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±1.8% / max. ±2.5% RH digital humidity and temperature sensor with protective cover
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SHT41-AD1P-R2

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±1.8% / max. ±3.5% RH digital humidity and temperature sensor with protective cover
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SHT40-AD1P-R2

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ASIL-A safety element out of context humidity sensor
Upcoming

SHT41A-AWSB

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±2% Digital humidity and temperature sensor / 0x45 I2C Output
New

SHT40I-BD1B

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±1.8% / max. ±3.5% RH Digital humidity & temp. sensor / 0x46 I2C Output
New

SHT40-CD1B

  • Sensor
  • Humidity
±1.8% / max. ±3.5% RH Digital humidity & temp. sensor / 0x45 I2C Output
New

SHT40-BD1B

  • Sensor
  • Humidity

SHT43 humidity and temperature sensor demonstrator

±1.8% / max. ±2.5% RH digital humidity and temperature sensor with protective cover

±1.8% / max. ±3.5% RH digital humidity and temperature sensor with protective cover

ASIL-A safety element out of context humidity sensor

±2% Digital humidity and temperature sensor / 0x45 I2C Output

±1.8% / max. ±3.5% RH Digital humidity & temp. sensor / 0x46 I2C Output

±1.8% / max. ±3.5% RH Digital humidity & temp. sensor / 0x45 I2C Output