Si7021 Relative Humidity And Temperature Sensor - Silicon Laboratories SLWSTK6242A User Manual

5.4 Si7021 Relative Humidity and Temperature Sensor

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The Si7021 I C relative humidity and temperature sensor is a monolithic CMOS IC integrating humidity and temperature sensor ele-
ments, an analog-to-digital converter, signal processing, calibration data, and an I
low-K polymeric dielectrics for sensing humidity enables the construction of low-power, monolithic CMOS Sensor ICs with low drift and
hysteresis, and excellent long term stability.
The humidity and temperature sensors are factory-calibrated and the calibration data is stored in the on-chip non-volatile memory. This
ensures that the sensors are fully interchangeable, with no recalibration or software changes required.
The Si7021 is available in a 3x3 mm DFN package and is reflow solderable. It can be used as a hardware- and software-compatible
drop-in upgrade for existing RH/ temperature sensors in 3x3 mm DFN-6 packages, featuring precision sensing over a wider range and
lower power consumption. The optional factory-installed cover offers a low profile, convenient means of protecting the sensor during
assembly (e.g., reflow soldering) and throughout the life of the product, excluding liquids (hydrophobic/oleophobic) and particulates.
The Si7021 offers an accurate, low-power, factory-calibrated digital solution ideal for measuring humidity, dew-point, and temperature,
in applications ranging from HVAC/R and asset tracking to industrial and consumer platforms.
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The I C bus used for the Si7021 is shared with the Expansion Header. The temperature sensor is normally isolated from the I
use the sensor, SENSOR_ENABLE (tied high) must be set high. When enabled, the sensor's current consumption is included in the
AEM measurements.
PD7 (I2C0_SCL#1)
PD6 (I2C0_SDA#1)
ON (tied high)
EZR32
Please refer to the Silicon Labs web pages for more information:
silabs.com | Building a more connected world.
VMCU
SENSOR_I2C_SCL
SENSOR_I2C_SDA
SENSOR_ENABLE
0: I2C lines are isolated, sensor is not powered
1: Sensor is powered and connected
Figure 5.4. Si7021 Relative Humidity and Temperature Sensor
UG192: EZR32HG 915 MHz 20 dBm Wireless Starter Kit User's Guide
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C Interface. The patented use of industry-standard,
VDD
SCL
SDA
http://www.silabs.com/humidity-sensors
Peripherals
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C line. To
Si7021
Temperature
& Humidity
Sensor
Rev. 1.01 | 18