Datasheet SHT7x (SHT71, SHT75) Humidity and Temperature Sensor IC 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(R) 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. Dimensions Sensor Chip SHT7x is supplied on FR4 with pins which allows for easy integration or replacement. The same sensor is also available as surface mountable packaging (SHT1x) or on flex print (SHTA1). 3.1 2.2 3.7 O 0.4 6.4 B2G 13.5 0.6 1.2 19.5 3.7 71 Material Contents 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. 1 2 3 4 6.0 3.4 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. Evaluation Kits 0.46 1.27 5.08 0.2 2.0 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. www.sensirion.com For sensor trial measurements, for qualification of the sensor or even experimental application (data logging) of the sensor there is an evaluation kit EK-H4 available including SHT71 (same sensor chip as SHT1x) and 4 sensor channels, hard and software to interface with a computer. For other evaluation kits please check www.sensirion.com/humidity. Version 5 - December 2011 1/12 Datasheet SHT7x Sensor Performance Relative Humidity12 Parameter Temperature45 Condition min 0.4 8 Resolution1 typ 0.05 12 max 0.05 12 Units %RH bit %RH Accuracy2 SHT71 typ max 3.0 see Figure 2 Accuracy2 SHT75 typ max 1.8 see Figure 2 %RH 0.1 %RH 1 %RH Repeatability Hysteresis 3 <<1 8 raw data linearized tau 63% Nonlinearity time3 Response Operating Range Long term drift4 0 normal < 0.5 %RH %RH s 100 %RH %RH/yr Parameter Condition min 0.04 12 Resolution1 typ 0.01 14 max 0.01 14 Units C bit C Accuracy2 SHT71 typ max 0.4 see Figure 3 Accuracy2 SHT75 typ 0.3 see Figure 3 C max 0.1 C C F s C/yr Repeatability -40 -40 5 Operating Range Response Time 6 Long term drift tau 63% 123.8 254.9 30 < 0.04 3.0 6 2.5 (%RH) 4 2.0 SHT71 DT (C) SHT71 DRH 1.5 2 1.0 SHT75 SHT75 0.5 0 0.0 0 10 20 30 40 50 60 70 80 90 100 -40 -20 0 20 40 60 Figure 2: Maximal RH-tolerance at 25C per sensor type. Figure 3: Maximal T-tolerance per sensor type. Electrical and General Items Packaging Information Power Consumption5 Communication Storage typ max Units 3.3 5.5 V sleep 2 5 W measuring 3 mW average 90 W digital 2-wire interface, see Communication 10 - 50C (0 - 80C peak), 20 - 60%RH 1 Condition min 2.4 The default measurement resolution of is 14bit for temperature and 12bit for humidity. It can be reduced to 12/8bit by command to status register. 2 Accuracies are tested at Outgoing Quality Control at 25C (77F) and 3.3V. Values exclude hysteresis and are only applicable to non-condensing environments. 3 Time for reaching 63% of a step function, valid at 25C and 1 m/s airflow. www.sensirion.com 100 Temperature (C) Relative Humidity (%RH) Parameter Source Voltage 80 Sensor Type SHT71 SHT75 Packaging Tape Stripes Tape Stripes Quantity 50 50 Order Number 1-100092-04 1-100071-04 This datasheet is subject to change and may be amended without prior notice. 4 Value may be higher in environments with high contents of volatile organic compounds. See Section 1.3 of Users Guide. 5 Values for VDD=3.3V at 25C, average value at one 12bit measurement per second. 6 Response time depends on heat capacity of and thermal resistance to sensor substrate. Version 5 - December 2011 2/12 Users Guide SHT7x 1 Application Information Relative Humidity (%) 1.1 Operating Conditions Sensor works stable within recommended normal range - see Figure 4. Long term exposures to conditions outside normal range, especially at humidity >80%RH, may temporarily offset the RH signal (+3 %RH after 60h). After return to normal range it will slowly return towards calibration state by itself. See Section 1.4 "Reconditioning Procedure" to accelerate eliminating the offset. Prolonged exposure to extreme conditions may accelerate ageing. 100 Max. Range 80 60 40 Normal Range For these reasons it is recommended to store the sensors in original packaging including the sealed ESD bag at following conditions: Temperature shall be in the range of 10C - 50C (0 - 80C for limited time) and humidity at 20 - 60%RH (sensors that are not stored in ESD bags). For sensors that have been removed from the original packaging we recommend to store them in ESD bags made of metal-in PE-HD8. In manufacturing and transport the sensors shall be prevented of high concentration of chemical solvents and long exposure times. Out-gassing of glues, adhesive tapes and stickers or out-gassing packaging material such as bubble foils, foams, etc. shall be avoided. Manufacturing area shall be well ventilated. For more detailed information please consult the document "Handling Instructions" or contact Sensirion. 20 0 -40 -20 0 20 40 60 80 100 120 Temperature (C) Figure 4: Operating Conditions 1.2 Sockets and Soldering For maintain high accuracy specifications the sensor shall not be soldered. Sockets may be used such as "Preci-dip / Mill-Max R851-83-004-20-001" or similar. Standard wave soldering ovens may be used at maximum 235C for 20 seconds. For manual soldering contact time must be limited to 5 seconds at up to 350C7. After wave soldering the devices should be stored at >75%RH for at least 12h to allow the polymer to rehydrate. Alternatively the re-hydration process may be performed at ambient conditions (>40%RH) during more than 5 days. In no case, neither after manual nor wave soldering, a board wash shall be applied. In case of application with exposure of the sensor to corrosive gases the soldering pads of pins and PCB shall be sealed to prevent loose contacts or short cuts. 1.3 Storage Conditions and Handling Instructions It is of great importance to understand that a humidity sensor is not a normal electronic component and needs to be handled with care. Chemical vapors at high concentration in combination with long exposure times may offset the sensor reading. 1.4 Reconditioning Procedure As stated above extreme conditions or exposure to solvent vapors may offset the sensor. The following reconditioning procedure may bring the sensor back to calibration state: Baking: Re-Hydration: 1.5 Temperature Effects Relative humidity reading strongly depends on temperature. Therefore, it is essential to keep humidity sensors at the same temperature as the air of which the relative humidity is to be measured. In case of testing or qualification the reference sensor and test sensor must show equal temperature to allow for comparing humidity readings. The packaging of SHT7x is designed for minimal heat transfer from the pins to the sensor. Still, if the SHT7x shares a PCB with electronic components that produce heat it should be mounted in a way that prevents heat transfer or keeps it as low as possible. Furthermore, there are self-heating effects in case the measurement frequency is too high. Please refer to Section 3.3 for detailed information. 8 9 7 235C corresponds to 455F, 350C corresponds to 662F www.sensirion.com 100 - 105C at < 5%RH for 10h 20 - 30C at ~ 75%RH for 12h 9. For example, 3M antistatic bag, product "1910" with zipper . 75%RH can conveniently be generated with saturated NaCl solution. 100 - 105C correspond to 212 - 221F, 20 - 30C correspond to 68 - 86F Version 5 - December 2011 3/12 1.8 Wiring Considerations and Signal Integrity SHT7x are often applied using wires. Carrying the SCK and DATA signal parallel and in close proximity more than 10cm may result in cross talk and loss of communication. This may be resolved by routing VDD and/or GND between the two data signals and/or using shielded cables. Furthermore, slowing down SCK frequency will possibly improve signal integrity. Please see the Application Note "ESD, Latch-up and EMC" for more information. 1.9 ESD (Electrostatic Discharge) ESD immunity is qualified according to MIL STD 883E, method 3015 (Human Body Model at 2 kV). Latch-up immunity is provided at a force current of 100mA with Tamb = 80C according to JEDEC78A. See Application Note "ESD, Latch-up and EMC" for more information. 2 Interface Specifications Pin 1 2 3 4 Name SCK VDD GND DATA Comment Serial Clock, input only Source Voltage Ground Serial Data, bidirectional 71 2.1 Power Pins (VDD, GND) The supply voltage of SHT7x must be in the range of 2.4 and 5.5V, recommended supply voltage is 3.3V. Decoupling of VDD and GND by a 100nF capacitor is integrated on the backside of the sensor packaging. The serial interface of the SHT7x is optimized for sensor readout and effective power consumption. The sensor cannot be addressed by I2C protocol, however, the sensor can be connected to an I2C bus without interference with other devices connected to the bus. Microcontroller must switch between protocols. SHT7x (Slave) B2G 71 MicroController (Master) DATA SCK RP For sealing and gluing (use sparingly): Use high filled epoxy for electronic packaging (e.g. glob top, underfill), and Silicone. Out-gassing of these materials may also contaminate the SHT7x (see Section 1.3). Therefore try to add the sensor as a last manufacturing step to the assembly, store the assembly well ventilated after manufacturing or bake at 50C for 24h to outgas contaminants before packing. Table 1: SHT7x pin assignment. 1 2 3 4 10k 1.7 Materials Used for Sealing / Mounting Many materials absorb humidity and will act as a buffer increasing response times and hysteresis. Materials in the vicinity of the sensor must therefore be carefully chosen. Recommended materials are: Any metals, LCP, POM (Delrin), PTFE (Teflon), PE, PEEK, PP, PB, PPS, PSU, PVDF, PVF. B2G 1.6 Light The SHT7x is not light sensitive. Prolonged direct exposure to sunshine or strong UV radiation may age the housing. 1 2 3 4 Datasheet SHT7x VDD GND Figure 5: Typical application circuit, including pull up resistor RP. 2.2 Serial clock input (SCK) SCK is used to synchronize the communication between microcontroller and SHT7x. Since the interface consists of fully static logic there is no minimum SCK frequency. 2.3 Serial data (DATA) The DATA tri-state pin is used to transfer data in and out of the sensor. For sending a command to the sensor, DATA is valid on the rising edge of the serial clock (SCK) and must remain stable while SCK is high. After the falling edge of SCK the DATA value may be changed. For safe communication DATA valid shall be extended TSU and THO before the rising and after the falling edge of SCK, respectively - see Figure 6. For reading data from the sensor, DATA is valid TV after SCK has gone low and remains valid until the next falling edge of SCK. To avoid signal contention the microcontroller must only drive DATA low. An external pull-up resistor (e.g. 10 k) is required to pull the signal high - it should be noted that pull-up resistors may be included in I/O circuits of www.sensirion.com Version 5 - December 2011 4/12 Datasheet SHT7x microcontrollers. See Table 2 for detailed I/O characteristic of the sensor. 2.4 Electrical Characteristics The electrical characteristics such as power consumption, low and high level, input and output voltages depend on the supply voltage. Table 2 gives electrical characteristics of SHT7x with the assumption of 5V supply voltage if not stated otherwise. For proper communication with the sensor it is essential to make sure that signal design is strictly within the limits given in Table 3 and Figure 6. Absolute maximum ratings for VDD versus GND are +7V and -0.3V. Exposure to absolute maximum rating conditions for extended periods may affect the sensor reliability (e.g. hot carrier degradation, oxide breakdown). Parameter Conditions min Power supply DC10 2.4 measuring Supply current average11 2 sleep Low level output IOL < 4 mA 0 voltage High level output RP < 25 k 90% voltage Low level input Negative going 0% voltage High level input Positive going 80% voltage Input current on pads on Output current Tri-stated (off) typ 3.3 0.55 28 0.3 max Units 5.5 V 1 mA A 1.5 A 250 mV 100% VDD 20% VDD 100% VDD 10 1 A 4 20 mA A Table 2: SHT7x DC characteristics. RP stands for pull up resistor, while IOL is low level output current. TSCK TSCKH TSCKL TR TF Parameter FSCK SCK Frequency Conditions min typ max Units VDD > 4.5V 0 0.1 5 MHz VDD < 4.5V 0 0.1 1 MHz TSCKx SCK hi/low time 100 ns TR/TF SCK rise/fall time 1 200 * ns OL = 5pF 3.5 10 20 ns OL = 100pF 30 40 200 ns ** ** ** ns TFO DATA fall time TRO DATA rise time TV DATA valid time 200 250 *** ns TSU DATA setup time 100 150 *** ns THO DATA hold time 10 **** ns * TR_max + TF_max = (FSCK)-1 - TSCKH - TSCKL ** TR0 is determined by the RP*Cbus time-constant at DATA line *** TV_max and TSU_max depend on external pull-up resistor (RP) and total bus line capacitance (Cbus) at DATA line **** TH0_max < TV - max (TR0, TF0) 15 Table 3: SHT7x I/O signal characteristics, OL stands for Output Load, entities are displayed in Figure 6. 3 Communication with Sensor 3.1 Start up Sensor As a first step the sensor is powered up to chosen supply voltage VDD. The slew rate during power up shall not fall below 1V/ms. After power-up the sensor needs 11ms to get to Sleep State. No commands must be sent before that time. 3.2 Sending a Command To initiate a transmission, a Transmission Start sequence has to be issued. It consists of a lowering of the DATA line while SCK is high, followed by a low pulse on SCK and raising DATA again while SCK is still high - see Figure 7. 80% SCK 20% THO TSU DATA valid write DATA valid read TV DATA SCK 80% 20% Recommended voltage supply for highest accuracy is 3.3V, due to sensor calibration. 11 Minimum value with one measurement of 8 bit resolution without OTP reload per second, typical value with one measurement of 12bit resolution per second. www.sensirion.com 20% TRO TFO Figure 6: Timing Diagram, abbreviations are explained in Table 3. Bold DATA line is controlled by the sensor, plain DATA line is controlled by the micro-controller. Note that DATA valid read time is triggered by falling edge of anterior toggle. 10 80% DATA 80% 20% Figure 7: "Transmission Start" sequence The subsequent command consists of three address bits (only `000' is supported) and five command bits. The SHT7x indicates the proper reception of a command by pulling the DATA pin low (ACK bit) after the falling edge of the 8th SCK clock. The DATA line is released (and goes high) after the falling edge of the 9th SCK clock. Version 5 - December 2011 5/12 Datasheet SHT7x Important: To keep self heating below 0.1C, SHT7x should not be active for more than 10% of the time - e.g. maximum one measurement per second at 12bit accuracy shall be made. 3.4 Connection reset sequence If communication with the device is lost the following signal sequence will reset the serial interface: While leaving DATA high, toggle SCK nine or more times - see Figure 8. This must be followed by a Transmission Start sequence preceding the next command. This sequence resets the interface only. The status register preserves its content. www.sensirion.com 80% Figure 8: Connection Reset Sequence 3.5 CRC-8 Checksum calculation The whole digital transmission is secured by an 8bit checksum. It ensures that any wrong data can be detected and eliminated. As described above this is an additional feature of which may be used or abandoned. Please consult Application Note "CRC Checksum" for information on how to calculate the CRC. 3.6 Status Register Some of the advanced functions of the SHT7x such as selecting measurement resolution, end-of-battery notice, use of OTP reload or using the heater may be activated by sending a command to the status register. The following section gives a brief overview of these features. 0 0 0 0 0 1 1 0 Status Register ACK After the command Status Register Read or Status Register Write - see Table 4 - the content of 8 bits of the status register may be read out or written. For the communication compare Figure 9 and Figure 10 - the assignation of the bits is displayed in Table 5. 0 0 0 0 0 1 1 1 Status Register Checksum ACK Figure 9: Status Register Write Figure 10: Status Register Read Examples of full communication cycle are displayed in Figure 11 and Figure 12. 0 0 0 Command LSB Wait for 0 0 DATA ready MSB Checksum ACK Communication terminates after the acknowledge bit of the CRC data. If CRC-8 checksum is not used the controller may terminate the communication after the measurement data LSB by keeping ACK high. The device automatically returns to Sleep Mode after measurement and communication are completed. 20% ACK Bit 7 Two bytes of measurement data and one byte of CRC checksum (optional) will then be transmitted. The micro controller must acknowledge each byte by pulling the DATA line low. All values are MSB first, right justified (e.g. the 5th SCK is MSB for a 12bit value, for a 8bit result the first byte is not used). 80% 9 20% LSb ACK After issuing a measurement command (`00000101' for relative humidity, `00000011' for temperature) the controller has to wait for the measurement to complete. This takes a maximum of 20/80/320 ms for a 8/12/14bit measurement. The time varies with the speed of the internal oscillator and can be lower by up to 30%. To signal the completion of a measurement, the SHT7x pulls data line low and enters Idle Mode. The controller must wait for this Data Ready signal before restarting SCK to readout the data. Measurement data is stored until readout, therefore the controller can continue with other tasks and readout at its convenience. 4-8 DATA ACK Bit 7 Measurement of RH and T 3 2 ACK Bit 7 3.3 2 Transmission Start TS Table 4: SHT7x list of commands SCK 1 TS Code 0000x 00011 00101 00111 00110 0101x-1110x 11110 TS Command Reserved Measure Temperature Measure Relative Humidity Read Status Register Write Status Register Reserved Soft reset, resets the interface, clears the status register to default values. Wait minimum 11 ms before next command Figure 11: Overview of Measurement Sequence. TS = Transmission Start, MSB = Most Significant Byte, LSB = Last Significant Byte, LSb = Last Significant Bit. Version 5 - December 2011 6/12 Datasheet SHT7x Transmission Start Address = `000' A2 A1 A0 Command = `00101' C3 C2 C1 C0 C4 Measurement (80ms for 12bit) ACK SCK DATA A2 Idle Bits 14 13 15 12 MSb 11 A1 10 A0 9 8 C4 C3 C2 C1 ACK C0 12bit Humidity Data ACK 7 6 5 4 Sensor pulls DATA line low after completion of measurement 3 2 1 LSb 0 Skip ACK to end transmission (if no CRC is used) ACK SCK DATA 15 13 14 MSb 7 12 6 5 10 11 9 ACK 8 CRC-8 Checksum 4 3 2 1 7 6 5 4 3 Sleep (wait for next measurement) LSb 0 ACK 0 ACK 2 0 1 ACK Transmission Start SCK DATA 7 6 5 4 3 2 1 Figure 12: Example RH measurement sequence for value "0000'0100"0011'0001" = 1073 = 35.50%RH (without temperature compensation). DATA valid times are given and referenced in boxes on DATA line. Bold DATA lines are controlled by sensor while plain lines are controlled by the micro-controller. Bit Type Description Default 7 reserved 0 End of Battery (low voltage No default value, detection) bit is only updated X 6 R `0' for VDD > 2.47 after a `1' for VDD < 2.47 measurement 5 reserved 0 4 reserved 0 3 For Testing only, do not use 0 2 R/W Heater 0 off 1 R/W no reload from OTP 0 reload '1' = 8bit RH / 12bit Temp. resolution 12bit RH 0 R/W 0 '0' = 12bit RH / 14bit Temp. 14bit Temp. resolution For example the heater can be helpful for functionality analysis: Humidity and temperature readings before and after applying the heater are compared. Temperature shall increase while relative humidity decreases at the same time. Dew point shall remain the same. Table 5: Status Register Bits 4 Conversion of Signal Output Measurement resolution: The default measurement resolution of 14bit (temperature) and 12bit (humidity) can be reduced to 12 and 8bit. This is especially useful in high speed or extreme low power applications. 4.1 Relative Humidity For compensating non-linearity of the humidity sensor - see Figure 13 - and for obtaining the full accuracy of the sensor it is recommended to convert the humidity readout (SORH) with the following formula with coefficients given in Table 6: End of Battery function detects and notifies VDD voltages below 2.47 V. Accuracy is 0.05 V. Heater: An on chip heating element can be addressed by writing a command into status register. The heater may increase the temperature of the sensor by 5 - 10C12 beyond ambient temperature. The heater draws roughly 8mA @ 5V supply voltage. Please note: The temperature reading will display the temperature of the heated sensor element and not ambient temperature. Furthermore, the sensor is not qualified for continuous application of the heater. OTP reload: With this operation the calibration data is uploaded to the register before each measurement. This may be deactivated for reducing measurement time by about 10ms. RH linear = c 1 + c 2 SO RH + c 3 SO RH (%RH) 2 SORH 12 bit 8 bit c1 -2.0468 -2.0468 c2 0.0367 0.5872 c3 -1.5955E-6 -4.0845E-4 Table 6: Humidity conversion coefficients 12 Corresponds to 9 - 18F www.sensirion.com Version 5 - December 2011 7/12 Datasheet SHT7x Values higher than 99%RH indicate fully saturated air and must be processed and displayed as 100%RH13. Please note that the humidity sensor has no significant voltage dependency. Relative Humidity 100% 80% 60% 40% 20% 0% 0 500 1000 1500 2000 2500 3000 3500 SORH sensor readout (12bit) Figure 13: Conversion from SORH to relative humidity 4.2 Temperature compensation of Humidity Signal For temperatures significantly different from 25C (~77F) the humidity signal requires temperature compensation. The temperature correction corresponds roughly to 0.12%RH/C @ 50%RH. Coefficients for the temperature compensation are given in Table 8. RH true = (TC - 25) (t 1 + t 2 SO RH ) + RHlinear SORH 12 bit 8 bit t1 0.01 0.01 SOT 14bit 12bit Temperature Range Above water, 0 - 50C Above ice, -40 - 0C Tn (C) 243.12 272.62 m 17.62 22.46 For more information on dew point calculation see Application Note "Introduction to Humidity". T = d1 + d 2 SO T d1 (F) -40.2 -39.6 -39.5 -39.3 -38.9 RH m T ln + 100% Tn + T Td (RH, T ) = Tn RH m T m - ln - 100% Tn + T Please note that "ln(...)" denotes the natural logarithm. For RH and T the linearized and compensated values for relative humidity and temperature shall be applied. t2 0.00008 0.00128 4.3 Temperature The band-gap PTAT (Proportional To Absolute Temperature) temperature sensor is very linear by design. Use the following formula to convert digital readout (SOT) to temperature value, with coefficients given in Table 9: d1 (C) -40.1 -39.8 -39.7 -39.6 -39.4 For dew point (Td) calculations there are various formulas to be applied, most of them quite complicated. For the temperature range of -40 - 50C the following approximation provides good accuracy with parameters given in Table 10: Table 9: Parameters for dew point (Td) calculation. Table 7: Temperature compensation coefficients VDD 5V 4V 3.5V 3V 2.5V 4.4 Dew Point SHT7x is not measuring dew point directly, however dew point can be derived from humidity and temperature readings. Since humidity and temperature are both measured on the same monolithic chip, the SHT7x allows superb dew point measurements. d2 (C) 0.01 0.04 d2 (F) 0.018 0.072 Table 8: Temperature conversion coefficients. 5 Environmental Stability If sensors are qualified for assemblies or devices, please make sure that they experience same conditions as the reference sensor. It should be taken into account that response times in assemblies may be longer, hence enough dwell time for the measurement shall be granted. For detailed information please consult Application Note "Testing Guide". SHT7x have been tested according to the test conditions given in Table 11. Sensor performance under other test conditions cannot be guaranteed and is not part of the sensor specifications. Especially, no guarantee can be given for sensor performance in the field or for customer's specific application. Please contact Sensirion for detailed information. 13 If wetted excessively (strong condensation of water on sensor surface), sensor output signal can drop below 100%RH (even below 0%RH in some cases), but the sensor will recover completely when water droplets evaporate. The sensor is not damaged by water immersion or condensation. www.sensirion.com Version 5 - December 2011 8/12 Datasheet SHT7x Environment Standard HTOL 125C, 1000 h TC THU -40C - 125C, 500 cycles Acc. JESD22-A104-C 85C / 85%RH, 1000h Results 14 Within specifications Within specifications Within specifications Qualified ESD immunity MIL STD 883E, method 3015 (Human Body Model at 2kV) Latch-up force current of 100mA with Qualified Tamb = 80C, acc. JEDEC 17 Lot No.: Quantity: RoHS: XX0-NN-YRRRTTTTT RRRR Compliant Lot No. Figure 14: First label on reel: XX = Sensor Type (71 for SHT71), NN = Chip Version (04 for V4), Y = last digit of year, RRR = number of sensors on reel divided by 10 (200 for 2000 units), TTTTT = Traceability Code. Table 10: Qualification tests: HTSL = High Temperature Storage Lifetime, TC = Temperature Cycles, UHST = Unbiased Highly accelerated temperature and humidity Test, THU = Temperature humidity unbiased Device Type: Description: 6 Packaging 6.1 Packaging type The device is supplied in a single-in-line pin type package. The sensor housing consists of a Liquid Crystal Polymer (LCP) cap with epoxy glob top on a standard 0.6 mm FR4 substrate. The sensor head is connected to the pins, by a small bridge to minimize heat conduction and response times. The pins are made of Cu/Be alloy coated with 1.3m Ni and 0.5m Au, which are soldered to the FR4 substrate by lead-free solder paste. The gold plated back side of the sensor head is connected to the GND pin. A 100nF capacitor is mounted on the back side between VDD and GND. The device is fully RoHS and WEEE compliant - thus it is free of of Pb, Cd, Hg, Cr(6+), PBB and PBDE. Size including pins is 19.5 x 5.08 x 3.1mm. Total weight: 168 mg, weight of sensor head: 73 mg. All pins are Au plated to avoid corrosion. They can be soldered or mate with most 1.27 mm (0.05'') sockets, for example: Preci-dip / Mill-Max R851-83-004-20-001 or similar. 6.2 Traceability Information All SHT7x are marked with an alphanumeric, three digit code on the chip cap - see "B2G" on Figure 1. The lot numbers allow full traceability through production, calibration and testing. No information can be derived from the code directly, respective data is stored at Sensirion. 1-100PPP-NN Humidity & Temperature Sensor SHTxx Part Order No. 1-100PPP-NN or Customer Number Date of Delivery: DD.MM.YYYY Order Code: 45CCCC / 0 Figure 15: Second label on reel: For Device Type and Part Order Number please refer to Table 12, Delivery Date (also Date Code) is date of packaging of sensors (DD = day, MM = month, YYYY = year), CCCC = number of order. 6.3 Shipping Package SHT7x are shipped in 32mm tape at 50pcs each - for details see Figure 16 and Table 12. Reels are individually labeled with barcode and human readable labels, see section 6.2. Sensor Type SHT71 SHT75 Packaging Tape Stripes Tape Stripes Quantity 50 50 Order Number 1-100092-04 1-100071-04 Table 11: Packaging types per sensor type. Dimensions of packaging tape are given in Figure 16. All tapes have a 7 pockets empty leader tape (first pockets of the tape) and a 7 pockets empty trailer tape (last pockets of the tape). Labels on the reels are displayed in Figure 14 and Figure 15, they both give traceability information. 14 According to accuracy and long term drift specification given on Page 2. www.sensirion.com Version 5 - December 2011 9/12 2.00 0.10 12.00 4.00 O2.0 MIN O1.5 MIN 3.6 2.7 5.6 R0.75 TYP R0.5 TYP 32.0 0.3 28.4 0.1 0.20 0.05 20.5 71 14.2 B2G 14.1 R0.30 MAX 6.4 0.30 1.75 0.10 Datasheet SHT7x Figure 16: Tape configuration and unit orientation within tape, dimensions in mm (1mm = 0.039inch). Leader tape is to the right of the figure, trailer tape to the left. www.sensirion.com Version 5 - December 2011 10/12 Datasheet SHT7x Revision History Date March 2007 July 2008 April 2009 May 2010 December 2011 www.sensirion.com Version 3.0 4.0 4.2 4.3 5 Page(s) 1 - 10 1 - 10 2, 7 1 - 11 1, 7-9 Changes Data sheet valid for SHTxx-V4 and SHTxx-V3 New release, rework of datasheet Amended foot note 2, communication diagram changed (Figure 12) Errors eliminated, information added - for details please ask for change protocol. References to V3 sensors eliminated. Version 5 - December 2011 11/12 Datasheet SHT7x Important Notices Warning, Personal Injury Do not use this product as safety or emergency stop devices or in any other application where failure of the product could result in personal injury. Do not use this product for applications other than its intended and authorized use. Before installing, handling, using or servicing this product, please consult the data sheet and application notes. Failure to comply with these instructions could result in death or serious injury. If the Buyer shall purchase or use SENSIRION products for any unintended or unauthorized application, Buyer shall defend, indemnify and hold harmless SENSIRION and its officers, employees, subsidiaries, affiliates and distributors against all claims, costs, damages and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if SENSIRION shall be allegedly negligent with respect to the design or the manufacture of the product. ESD Precautions The inherent design of this component causes it to be sensitive to electrostatic discharge (ESD). To prevent ESD-induced damage and/or degradation, take customary and statutory ESD precautions when handling this product. See application note "ESD, Latchup and EMC" for more information. Warranty SENSIRION warrants solely to the original purchaser of this product for a period of 12 months (one year) from the date of delivery that this product shall be of the quality, material and workmanship defined in SENSIRION's published specifications of the product. Within such period, if proven to be defective, SENSIRION shall repair and/or replace this product, in SENSIRION's discretion, free of charge to the Buyer, provided that: * notice in writing describing the defects shall be given to SENSIRION within fourteen (14) days after their appearance; * such defects shall be found, to SENSIRION's reasonable satisfaction, to have arisen from SENSIRION's faulty design, material, or workmanship; * the defective product shall be returned to SENSIRION's factory at the Buyer's expense; and * the warranty period for any repaired or replaced product shall be limited to the unexpired portion of the original period. This warranty does not apply to any equipment which has not been installed and used within the specifications recommended by SENSIRION for the intended and proper use of the equipment. EXCEPT FOR THE WARRANTIES EXPRESSLY SET FORTH HEREIN, SENSIRION MAKES NO WARRANTIES, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO THE PRODUCT. ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE EXPRESSLY EXCLUDED AND DECLINED. SENSIRION is only liable for defects of this product arising under the conditions of operation provided for in the data sheet and proper use of the goods. SENSIRION explicitly disclaims all warranties, express or implied, for any period during which the goods are operated or stored not in accordance with the technical specifications. SENSIRION does not assume any liability arising out of any application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or incidental damages. All operating parameters, including without limitation recommended parameters, must be validated for each customer's applications by customer's technical experts. Recommended parameters can and do vary in different applications. SENSIRION reserves the right, without further notice, (i) to change the product specifications and/or the information in this document and (ii) to improve reliability, functions and design of this product. Copyright(c) 2011, SENSIRION. CMOSens(R) is a trademark of Sensirion All rights reserved Headquarters and Subsidiaries SENSIRION AG Laubisruetistr. 50 CH-8712 Staefa ZH Switzerland Sensirion Inc., USA phone: +1 805 409 4900 info_us@sensirion.com www.sensirion.com Sensirion Korea Co. Ltd. phone: +82 31 345 0031 3 info@sensirion.co.kr www.sensirion.co.kr phone: +41 44 306 40 00 fax: +41 44 306 40 30 info@sensirion.com www.sensirion.com Sensirion Japan Co. Ltd. phone: +81 3 3444 4940 info@sensirion.co.jp www.sensirion.co.jp Sensirion China Co. Ltd. phone: +86 755 8252 1501 info@sensirion.com.cn www.sensirion.com.cn Sensirion AG (Germany) phone: +41 44 927 11 66 info@sensirion.com www.sensirion.com To find your local representative, please visit www.sensirion.com/contact www.sensirion.com Version 5 - December 2011 12/12 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Sensirion: SHT71 SHT75