SHT21S Datasheet, PDF (1/10 Pages) List of Unclassifed Manufacturers – Humidity and Temperature Sensor IC

Datasheet SHT21S
Humidity and Temperature Sensor IC
 Fully calibrated
 SDM interface convertible to analog output
 Low power consumption
 Excellent long term stability
 DFN type package – reflow solderable
Product Summary
The SHT21 humidity and temperature sensor of Sensirion
has become an industry standard in terms of form factor
and intelligence: Embedded in a reflow solderable Dual
Flat No leads (DFN) package of 3 x 3mm foot print and
1.1mm height it provides calibrated, linearized sensor
signals in analog Sigma Delta Modulated (SDM) format.
The SHT2x sensors contain a capacitive type humidity
sensor, a band gap temperature sensor and specialized
analog and digital integrated circuit – all on a single
CMOSens^® chip. This yields in an unmatched sensor
performance in terms of accuracy and stability as well as
minimal power consumption.
SDM signal is a pulse sequence that with a low pass filter
may be converted into analog voltage output. The data
signal is provided on SDA line. Pulling SCL high or low
allows for switching between humidity and temperature,
respectively. The sensor measures the physical values
twice per second.
Every sensor is individually calibrated and tested. Lot
identification is printed on the sensor.
With this set of features and the proven reliability and
long-term stability, the SHT2x sensors offer an
outstanding performance-to-price ratio. For testing SHT2x
two evaluation kits EK-H4 and EK-H5 are available.
Dimensions
3.0
0.3 typ
1.4 max
2.2
0.4 0.3
2.4
1.1
Bottom
View
NC VDD SCL
1.0 1.0
NC VSS SDA
Figure 1: Drawing of SHT21S sensor package, dimensions
are given in mm (1mm = 0.039inch), tolerances are ±0.1mm.
The die pad (center pad) is internally connected to VSS. The NC
pads must be left floating. Numbering of E/O pads starts at lower
right corner (indicated by notch in die pad) and goes clockwise
(compare Table 2).
Sensor Chip
SHT21S feature a generation 4C CMOSens® chip.
Besides the capacitive relative humidity sensor and the
band gap temperature sensor, the chip contains an
amplifier, A/D converter, OTP memory and a digital
processing unit.
Material Contents
While the sensor itself is made of Silicon the sensors’
housing consists of a plated Cu lead-frame and green
epoxy-based mold compound. The device is fully RoHS
and WEEE compliant, e.g. free of Pb, Cd and Hg.
Additional Information
Additional information such as Application Notes is
available from the web page www.sensirion.com/sht21.
For more information please contact Sensirion via
[e-mail].
www.sensirion.com
Version 4 – May 2014
1/10