Overview
The SHT21P humidity and temperature sensor from Sensirion AG is a highly regarded and widely used component in various industries. It is known for its compact form factor and advanced intelligence, making it an industry standard. The sensor is embedded in a reflow solderable Dual Flat No leads (DFN) package with a footprint of 3 x 3 mm and a height of 1.1 mm. It provides calibrated, linearized sensor signals in digital format via an I2C interface. The SHT21P features a generation 4C CMOSens® chip, which includes a capacitive relative humidity sensor, a band gap temperature sensor, an amplifier, an A/D converter, OTP memory, and a digital processing unit.
Key Specifications
| Parameter | Value | Notes |
|---|---|---|
| Humidity Range | 0 - 100% RH | |
| Humidity Accuracy | ±3% RH (typical at 25°C) | Excludes hysteresis and long-term drift |
| Temperature Range | -40°C to 125°C | |
| Temperature Accuracy | ±0.3°C (typical at 25°C) | |
| Response Time (τ63%) | 8 seconds (humidity), 5 seconds (temperature) | Valid at 25°C and 1 m/s airflow |
| Supply Voltage | 2.1 - 3.6 V | Recommended supply voltage is 3.0 V |
| Average Supply Current | 300 µA | |
| Max Supply Current | 330 µA | |
| Interface | I2C | 2-wire interface |
| Package Size | 3 x 3 x 1.1 mm³ |
Key Features
- Fully calibrated and linearized sensor signals in digital format via I2C interface.
- Low power consumption with an average supply current of 300 µA and a maximum of 330 µA.
- Excellent long-term stability and minimal drift.
- Compact DFN package suitable for reflow soldering.
- Embedded generation 4C CMOSens® chip with capacitive relative humidity sensor, band gap temperature sensor, amplifier, A/D converter, OTP memory, and digital processing unit.
- RoHS and WEEE compliant, free of Pb, Cd, and Hg.
Applications
The SHT21P is widely used in various applications, including but not limited to:
- Environmental monitoring systems.
- Industrial automation and control systems.
- Medical devices and healthcare equipment.
- Aerospace and automotive industries.
- Consumer electronics and smart home devices.
Its high accuracy, stability, and low power consumption make it a versatile choice for many different use cases.
Q & A
- What is the humidity range of the SHT21P sensor?
The SHT21P sensor measures humidity in the range of 0 to 100% RH. - What is the typical humidity accuracy of the SHT21P at 25°C?
The typical humidity accuracy is ±3% RH at 25°C, excluding hysteresis and long-term drift. - What is the operating temperature range of the SHT21P?
The operating temperature range is from -40°C to 125°C. - What is the response time of the SHT21P for humidity and temperature measurements?
The response time is 8 seconds for humidity and 5 seconds for temperature, valid at 25°C and 1 m/s airflow. - What is the recommended supply voltage for the SHT21P?
The recommended supply voltage is 3.0 V, although it can operate within a range of 2.1 to 3.6 V. - What interface does the SHT21P use for communication?
The SHT21P uses an I2C 2-wire interface for communication. - Is the SHT21P RoHS and WEEE compliant?
Yes, the SHT21P is RoHS and WEEE compliant, free of Pb, Cd, and Hg. - What is the package size of the SHT21P?
The package size is 3 x 3 x 1.1 mm³. - Does the SHT21P require any special handling during soldering?
Yes, the power supply pins (VDD, VSS) must be decoupled with a 100 nF capacitor, and the NC pads must be left floating. - Are there any evaluation kits available for the SHT21P?
Yes, Sensirion offers evaluation kits such as the EK-H4 and EK-H5 for the SHT2x series, which includes the SHT21P.
