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Datasheet SHT7x (SHT71, SHT75)

Humidity and Temperature Sensor Fully calibrated Digital output Low power consumption Excellent long term stability Pin type package – easy integration

Product Summary SHT7x (including SHT71 and SHT75) is Sensirion’s family of relative humidity and temperature sensors with pins. The sensors integrate sensor elements plus signal processing in compact format and provide a fully calibrated digital output. A unique capacitive 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 digital converter and a serial interface circuit. This results in superior signal quality, a fast response time and insensitivity to external disturbances (EMC). Each SHT7x is individually calibrated in a precision humidity chamber. The calibration coefficients are programmed 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 small size and low power consumption makes SHT7x the ultimate choice for even the most demanding applications. SHT7x is supplied on FR4 with pins which allows for easy integration or replacement. The same sensor is also available surface mountable packaging (SHT1x) or on flex p rint ( SHTA1 ) . Dimensions Sensor Chip
3.12.2 0.6 2.0 3.7 SHT7x V4 – for which this datasheet applies – features a version 4 Silicon sensor chip. Besides a humidity and a temperature sensor 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 “B2G” code on Figure 1.

B2G

6.4 Ø 0.4

71

1.2 6.0 3.4 3.7 13.5 Material Contents
19.5 1 2 3 4 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. Pins are made of a Cu/Be alloy coated with Ni and Au. The device is fully RoHS and WEEE compliant, thus it is free of Pb, Cd, Hg, Cr(6+), PBB and PBDE. Evaluation Kits For sensor trial measurements, for qualification of the sensor or even experimental application of the sensor there is an evaluation kit
0.46 1.275.08 0.2 EK-H2 available including sensor, hard and software to interface with a computer. For more sophisticated and demanding measurements a multi port evaluation kit
Figure 1: Drawing of SHT7x (applies to SHT71 and SHT75) sensor packaging, dimensions in mm (1mm = 0.039inch). Contact assignment: 1: SCK, 2: VDD, 3: GND, 4: DATA. Hatched item on backside of PCB is a 100nF capacitor – see Section 2.1 for more information. EK-H3 is available which allows for parallel application of up to 20 sensors.
www.sensirion.com Version 4.1 –September 2008