SHT1x / SHT7x Humidity & Temperature Sensor SHT7x Evaluation Kit Available SHT1x - Relative humidity and temperature sensors - Dew point - Fully calibrated, digital output - Excellent long-term stability - No external components required - Ultra low power consumption - Surface mountable or 4-pin fully interchangeable - Small size - Automatic power down SHT1x / SHT7x Product Summary The SHTxx is a single chip relative humidity and temperature multi sensor module comprising a calibrated digital output. Application of industrial CMOS processes with patented micro-machining (CMOSens(R) technology) ensures highest reliability and excellent long term stability. The device includes a capacitive polymer sensing element for relative humidity and a bandgap temperature sensor. Both are seamlessly coupled to a 14bit analog to digital converter and a serial interface circuit on the same chip. This results in superior signal quality, a fast response time and insensitivity to external disturbances (EMC) at a very competitive price. Each SHTxx is individually calibrated in a precision humidity chamber with a chilled mirror hygrometer as reference. The calibration coefficients are programmed into the OTP memory. These coefficients are used internally during measurements to calibrate the signals from the sensors. The 2-wire serial interface and internal voltage regulation allows easy and fast system integration. Its tiny size and low power consumption makes it the ultimate choice for even the most demanding applications. The device is supplied in either a surface-mountable LCC (Leadless Chip Carrier) or as a pluggable 4-pin single-in-line type package. Customer specific packaging options may be available on request. Applications Block Diagram _ HVAC _ Automotive _ Consumer Goods _ Weather Stations _ Humidifiers _ Dehumidifiers 1 SCK DATA D i -b 14 t Ordering Information A Digital 2wire Interface & CRC generator GND Humidity Temperature Part accuracy accuracy [K] Package Number [%RH] @ 25 C SHT11 3.0 0.4 SMD (LCC) SHT15 2.0 0.3 SMD (LCC) SHT71 3.0 0.4 4-pin single-in-line SHT75 1.8 0.3 4-pin single-in-line www.sensirion.com Calibration Memory %RH Sensor Amplification _ Test & Measurement _ Data Logging _ Automation _ White Goods _ Medical Temp. Sensor Sensirion, Eggbuhlstr. 14, 8052 Zurich, Switzerland, Tel: +41 1 306 40 00, Fax: +41 1 306 40 30 VDD v2.02 SHT1x / SHT7x Relative Humidity & Temperature Sensor System 1 Sensor Performance Specifications Parameter Conditions Min. Typ. Max. Units Humidity Resolution (2) 0.5 8 Repeatability Accuracy (1) Uncertainty Interchangeability Nonlinearity Range Response time linearized raw data linearized 1/e (63%) slowly moving air Hysteresis Long term stability Fully interchangeable %RH 3 <<1 %RH 0 100 %RH 4 s %RH %RH/yr C F bit C F 1/e (63%) 0.04 0.01 0.01 0.07 0.02 0.02 12 14 14 0.1 0.2 see figure 1 -40 123.8 -40 254.9 5 30 Accuracy Range C F s 3 SHT11/71 2 SHT15 1 SHT75 0 10 20 30 40 50 60 70 80 90 100 Temperature accuracy 3 C 2 C %RH 5.4 F 3.6 F SHT11/71 1 C 1.8 F SHT15/75 0 C 0 F -40C -40F 5 C 0C 32F 40C 104F 80C 176F 120C 248F Dewpoint accuracy @ 25 C (typical) 9.0 F 4 C 7.2 F 3 C 5.4 F 2 C SHT15 1 C 0 C SHT11/71 SHT75 3.6 F 1.8 F 0 10 20 30 40 50 60 70 80 90 100 Sensor Performance Specifications Figure 1 2 Relative Humidity absolute accuracy 4 0 1 < 0.5 Repeatability Table 1 %RH bit %RH typical Temperature Resolution (2) Response Time 0.03 0.03 12 12 0.1 see figure 1 %RH 5 %RH Rel. Humidity, Temperature and Dewpoint accuracies Interface Specifications Vdd 2.2.1 Serial clock input (SCK) GND uC DATA (master) SCK The SCK is used to synchronize the communication between a microcontroller and the SHTxx. Since the interface consists of fully static logic there is no minimum SCK frequency. SHT1x (slave) Vdd 2.4 - 5.5V Figure 2 Typical application circuit 2.2.2 Serial data (DATA) 2.1 Power Pins The SHTxx requires a voltage supply between 2.4 and 5.5 V. After powerup the device needs 11ms to reach its "sleep" state. No commands should be sent before that time. Power supply pins (VDD, GND) may be decoupled with a 100 nF capacitor. 2.2 Serial Interface (Bidirectional 2-wire) The serial interface of the SHTxx is optimized for sensor readout and power consumption and is not compatible with I2C interfaces, see FAQ for details. The DATA tristate pin is used to transfer data in and out of the device. DATA changes after the falling edge and is valid on the rising edge of the serial clock SCK. During transmission the DATA line must remain stable while SCK is high. To avoid signal contention the microcontroller should only drive DATA low. An external pull-up resistor (e.g. 10 k ) is required to pull the signal high. (See Figure 2) Pull-up resistors are often included in I/O circuits of microcontrollers. See Table 5 for detailed IO characteristics. (1) Each (2) The SHTxx is tested to be fully within RH accuracy specifications at 25 C (77 F) and 48 C (118.4 F) default measurement resolution of 14bit (temperature) and 12bit (humidity) can be reduced to 12 and 8 bit through the status register. www.sensirion.com v2.02 July 2004 2/9 SHT1x / SHT7x Relative Humidity & Temperature Sensor System therefore the controller can continue with other tasks and readout as convenient. 2.2.3 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. Two bytes of measurement data and one byte of CRC checksum will then be transmitted. The uC 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). 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 the measurement and communication have ended. DATA SCK Figure 3 "Transmission Start" sequence The subsequent command consists of three address bits (only "000" is currently supported) and five command bits. The SHTxx 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. Command Reserved Measure Temperature Measure 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 Table 2 Warning: To keep self heating below 0.1 C the SHTxx should not be active for more than 10% of the time (e.g. max. 2 measurements / second for 12bit accuracy). Code 0000x 00011 00101 00111 00110 0101x-1110x 11110 2.2.5 Connection reset sequence If communication with the device is lost the following signal sequence will reset its serial interface: While leaving DATA high, toggle SCK 9 or more times. 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. DATA Transmission Start SHTxx list of commands 2.2.4 Measurement sequence (RH and T) SCK After issuing a measurement command (`00000101' for RH, `00000011' for Temperature) the controller has to wait for the measurement to complete. This takes approximately 11/55/210 ms for a 8/12/14bit measurement. The exact time varies by up to 15% with the speed of the internal oscillator. To signal the completion of a measurement, the SHTxx pulls down the data line 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, Figure 4 Transmission Start Address='000' 1 2 4 -8 3 Connection reset sequence 2.2.6 CRC-8 Checksum calculation The whole digital transmission is secured by a 8 bit checksum. It ensures that any wrong data can be detected and eliminated. Please consult application note "CRC-8 Checksum Calculation" for information on how to calculate the CRC. Bold = SHT1xx controls DATA line Plain = uC controls DATA line Command='00101' Measurement ~55ms for 12 bit ~11ms for 8 bit DATA a2 a0 a1 C4 9 C3 C2 C1 C0 ack SCK Measurement is finished when the SHTxx pulls down the DATA line Skip acknowledge to end transmission (if no CRC is used) 12 bit humidity data DATA low low low low 11 10 9 8 ack 7 6 5 4 3 2 1 0 ack SCK MSB LSB CRC-8 Checksum wait for next measurement DATA 7 6 5 4 3 2 1 ack 0 SCK MSB Figure 5 Transmission Start Skip acknowledge to end transmission LSB Example RH measurement sequence for value "0000'1001 ' 0011'0001"= 2353 = 75.79 %RH (without temperature compensation) www.sensirion.com v2.02 July 2004 3/9 SHT1x / SHT7x Relative Humidity & Temperature Sensor System LSB ack MSB ack 0 LSB 0 0 0 ack ack TS wait for data ready Checksum Command Figure 6 Overview of Measurement Sequence (TS = Transmission Start) 2.3 Status Register Status Reg ack 0 00 0 01 1 0 ack Bit 7 TS Some of the advanced functions of the SHTxx are available through the status register. The following section gives a brief overview of these features. A more detailed description is available in the application note "Status Register" 2.4 Electrical Characteristics(1) Command VDD=5V, Temperature = 25 C unless otherwise noted Status Reg Checksum Parameter Power supply DC Supply current ack 000 0011 1 ack Bit 7 Status Register Write ack Bit 7 TS Figure 7 Command Figure 8 Status Register Read Bit Type 7 6 R Description reserved End of Battery (low voltage detection) `0' for Vdd > 2.47 `1' for Vdd < 2.47 5 4 3 2 1 0 reserved reserved For Testing only, do not use Heater no reload from OTP '1' = 8bit RH / 12bit Temperature resolution '0' = 12bit RH / 14bit Temperature resolution R/W R/W R/W Table 3 after switching on the heater, proper functionality of both sensors can be verified. * In high (>95 %RH) RH environments heating the sensor element will prevent condensation, improve response time and accuracy Warning: While heated the SHTxx will show higher temperatures and a lower relative humidity than with no heating. Default 0 X No default value, bit is only updated after a measurement 0 0 0 0 off 0 reload 0 12bit RH 14bit Temp. Status Register Bits 2.3.1 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. 2.3.2 End of Battery Min. Typ. 2.4 5 measuring 550 average 2(2) 28(3) sleep 0.3 Low level output voltage 0 High level output voltage 75% Low level input voltage Negative going 0 High level input voltage Positive going 80% Input current on pads Output peak current on Tristated (off) 10 Table 4 Conditions Min Typ. Max. FSCK VDD > 4.5 V 10 VDD < 4.5 V 1 TRFO DATA fall time Output load 5 pF 3.5 10 20 Output load 100 pF 30 40 200 TCLx SCK hi/low time 100 TV DATA valid time 250 TSU DATA set up time 100 THO DATA hold time 0 10 TR/TF SCK rise/fall time 200 Table 5 An on chip heating element can be switched on. It will increase the temperature of the sensor by 5-15 C (9-27 F). Power consumption will increase by ~8 mA @ 5 V. Applications: By comparing temperature and humidity values before and (3) Unit MHz MHz ns ns ns ns ns ns ns SHTxx I/O Signals Characteristics TR TCLH TF FSCK SCK 2.3.3 Heater (2) Max. Units 5.5 V A A 1 A 20% Vdd 100% Vdd 20% Vdd 100% Vdd 1 A 4 mA A SHTxx DC Characteristics Parameter SCK frequency The "End of Battery" function detects VDD voltages below 2.47 V. Accuracy is 0.05 V 1) Conditions TV TSU THO DATA Figure 9 Timing Diagram Parameters are periodically sampled and not 100% tested With one measurement of 8 bit accuracy without OTP reload per second With one measurement of 12bit accuracy per second www.sensirion.com v2.02 July 2004 4/9 SHT1x / SHT7x Relative Humidity & Temperature Sensor System 3 Converting Output to Physical Values 3.1 Relative Humidity 3.2 Temperature To compensate for the non-linearity of the humidity sensor and to obtain the full accuracy it is recommended to convert the readout with the following formula1: RHlinear = c 1 + c 2 * SORH + c 3 * SORH 2 The bandgap PTAT (Proportional To Absolute Temperature) temperature sensor is very linear by design. Use the following formula to convert from digital readout to temperature: SORH c1 c2 c3 12 bit -4 0.0405 -2.8 * 10-6 8 bit -4 0.648 -7.2 * 10-4 Table 6 Humidity conversion coefficients For simplified, less computation intense conversion formulas see application note "RH and Temperature Non-Linearity Compensation". The humidity sensor has no significant voltage dependency. Temperature = d1 + d 2 * SOT VDD 5V 4V 3.5V 3V 2.5V Table 8 d1 [C] d1 [F] SOT d2 [C] d2 [F] -40.00 -40.00 14bit 0.01 0.018 -39.75 -39.50 12bit 0.04 0.072 -39.66 -39.35 -39.60 -39.28 -39.55 -39.23 Temperature conversion coefficients & For improved accuracies in extreme temperatures with more computation intense conversion formulas see application note "RH and Temperature Non-Linearity Compensation". $ 3.3 Dewpoint %RH Since humidity and temperature are both measured on the same monolithic chip, the SHTxx allows superb dewpoint measurements. See application note "Dewpoint calculation" for more. " # # # SORH sensor readout (12bit) ! Figure 10 Conversion from SORH to relative humidity 3.1.1 Humidity Sensor RH/Temperature compensation For temperatures significantly different from 25 C (~77 F) the temperature coefficient of the RH sensor should be considered: RHtrue = (TC - 25) * (t1 + t 2 * SORH ) + RHlinear SORH t1 t2 12 bit 0.01 0.00008 8 bit 0.01 0.00128 Table 7 Temperature compensation coefficients This equals ~0.12 %RH / C @ 50 %RH 1 Where SORH is the sensor output for relative humidity www.sensirion.com v2.02 July 2004 5/9 SHT1x / SHT7x Relative Humidity & Temperature Sensor System 4 Applications Information 4.1 Operating and Storage Conditions 100 4.6 Light [%RH] Maximum operating conditions 80 60 4.7 Normal operating conditions 40 20 0 -40 [C] -20 0 20 40 The SHTxx is not light sensitive. Prolonged direct exposure to sunshine or strong UV radiation may age the housing. 60 80 100 120 Figure 11 Recommended operating conditions Conditions outside the recommended range may temporarily offset the RH signal up to 3 %RH. After return to normal conditions it will slowly return towards calibration state by itself. See 4.3 "Reconditioning Procedure" to accelerate this process. Prolonged exposure to extreme conditions may accelerate ageing. 4.2 Exposure to Chemicals 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: All Metals, LCP, POM (Delrin), PTFE (Teflon), PE, PEEK, PP, PB, PPS, PSU, PVDF, PVF For sealing and gluing (use sparingly): High filled epoxy for electronic packaging (e.g. glob top, underfill), and Silicone. Outgassing of these materials may also contaminate the SHTxx (cf. 4.2). Store well ventilated after manufacturing or bake at 50C for 24h to outgas contaminants before packing. 4.8 Wiring Considerations and Signal Integrity Chemical vapors may interfere with the polymer layers used for capacitive humidity sensors. The diffusion of chemicals into the polymer may cause a shift in both offset and sensitivity. In a clean environment the contaminants will slowly outgas. The reconditioning procedure described below will accelerate this process. High levels of pollutants may cause permanent damage to the sensing polymer. Carrying the SCK and DATA signal parallel and in close proximity (e.g. in wires) for 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. Please see the application note "ESD, Latchup and EMC" for more information. Power supply pins (VDD, GND) should be decoupled with a 100 nF capacitor if wires are used. 4.3 Reconditioning Procedure 4.9 Qualifications The following reconditioning procedure will bring the sensor back to calibration state after exposure to extreme conditions or chemical vapors. 80-90 C (176-194F) at < 5 %RH for 24h (baking) followed by 20-30 C (70-90F) at > 74 %RH for 48h (re-hydration) Extensive tests were performed in various environments. Please contact SENSIRION for detailed information. 4.4 Temperature Effects Environment Norm Results(1) Temperature Cycles HAST Pressure Cooker High Temperature and Humidity Salt Atmosphere Condensing Air Freezing cycles fully submerged Various Automotive Chemicals JESD22-A104-B -40 C / 125 C, 1000 cy JESD22-A110-B 2.3 bar 125 C 85 %RH JESD22-A101-B 85 C 85 %RH 1250h DIN-50021ss -20 / +90 C, 100 cy 30min dwell time DIN 72300-5 Within Specifications Reversible shift by +2 %RH Reversible shift by +2 %RH Within Spec. Within Spec. Reversible shift by +2 %RH Within Specifications The relative humidity of a gas strongly depends on its temperature. It is therefore essential to keep humidity sensors at the same temperature as the air of which the relative humidity is to be measured. If the SHTxx shares a PCB with electronic components that give off heat it should be mounted far away and below the heat source and the housing must remain well ventilated. To reduce heat conduction copper layers between the SHT1x and the rest of the PCB should be minimized and a slit may be milled in between (see figure 13). Table 9 4.5 Membranes 4.10 ESD (Electrostatic Discharge) A membrane may be used to prevent dirt from entering the housing and to protect the sensor. It will also reduce peak concentrations of chemical vapors. For optimal response times air volume behind the membrane must be kept to a minimum. For the SHT1x package Sensirion recommends the SF1 filter cap for optimal IP67 protection. 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 100 mA with Tamb = 80 C according to JEDEC 17. See application note "ESD, Latchup and EMC" for more information. (1) Qualification tests (excerpt) The temperature sensor passed all tests without any detectable drift. Package and electronics also passed 100% www.sensirion.com v2.02 July 2004 6/9 SHT1x / SHT7x Relative Humidity & Temperature Sensor System 5 Package Information 5.1 SHT1x (surface mountable) Pin 1 2 3 4 Name GND DATA SCK VDD NC Comment Ground Serial data, bidirectional Serial clock, input Supply 2.4 - 5.5 V Remaining pins must be left unconnected Table 10 SHT1x Pin Description For manual soldering contact time must be limited to 5 seconds at up to 350 C. After soldering the devices should be stored at >74 %RH for at least 24h to allow the polymer to rehydrate. Please consult the application note "Soldering procedure" for more information. 5.1.4 Mounting Examples 5.1.1 Package type The SHT1x is supplied in a surface-mountable LCC (Leadless Chip Carrier) type package. The sensors housing consists of a Liquid Crystal Polymer (LCP) cap with epoxy glob top on a standard 0.8 mm FR4 substrate. The device is free of lead, Cd and Hg. Device size is 7.42 x 4.88 x 2.5 mm (0.29 x 0.19 x 0.1 inch) Weight 100 mg The production date is printed onto the cap in white numbers in the form wwy. e.g. "351" = week 35, 2001. 5.1.2 Delivery Conditions The SHT1x are shipped in 12mm tape at 100pcs or 400pcs.. Reels are individually labelled with barcode and human readable labels. The Lot numbers allow full traceability through production, calibration and test. Slit to minimize heat transfer from the PCB Figure 13 SHT1x PCB Mounting example The SF1 membrane filter cap is available for optimal IP67 protection. When mounted through a housing the interior can be protected from the environment while still allowing high quality humidity measurements (see example below). o-ring housing housing 2.8mm Filtercap SHT1x Components Trailer Tape 300mm minimum Carrier Tape Cover Tape Leader Tape 480mm minimum PCB Figure 12 Tape configuration and unit orientation melted plastic pin 5.1.3 Soldering Information Standard reflow soldering ovens may be used. For details please see application note "soldering procedure". Top View 1.15 (0.04) 1.9 (0.07) Figure 14 SF1 IP67 filter cap mounting example Side View Recommended PCB Footprint 1.49 (0.06) 2.44 (0.1) 4.88 (0.19) 1.8 (0.07) actual size 3.48 (0.137) 7.08 (0.278) 1.27 1.27 1.27 (0.05) NC No copper inside this field 4 0.8 (0.03) NC 0.47 (0.018) 3 4.61 (0.2) NC 2.5 (0.1) 2 0.8 (0.03) NC 0.6 (0.02) 1 5.22 (0.2) NC 3.99 (0.16) 7.42 (0.29) 6.88 (0.27) 1.81 1.27 (0.07) (0.05) sensor opening NC 1.8 (0.07) Figure 15 SHT1x drawing and footprint dimensions in mm (inch) www.sensirion.com v2.02 July 2004 7/9 SHT1x / SHT7x Relative Humidity & Temperature Sensor System 5.2 SHT7x (4-pin single-in-line) Name SCK VDD GND DATA Comment Serial clock input Supply 2.4 - 5.5 V Ground Serial data bidirectional 0.4 (0.02) Pin 1 2 3 4 3.1 (0.12) 2.2 (0.09) 3.7 (0.15) Table 11 SHT7x Pin Description 3.7 (0.15) 1.2 (0.05) 2 3 4 ~6 (~0.24) 1 0.6 (0.024) 3.4 (0.13) 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 device is Cd and Hg free. The sensor head is connected to the pins by a small bridge to minimize heat conduction and response times. 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. All pins are gold plated to avoid corrosion. They can be soldered or mate with most 1.27 mm (0.05'') sockets e.g.: Preci-dip / Mill-Max 851-93-004-20-001 or similar Total weight: 168 mg, weight of sensor head: 73 mg 13.5 (0.53) 5.2.1 Package type1 The production date is printed onto the cap in white numbers in the form wwy. e.g. "351" = week 35, 2001. 5.2.2 Delivery Conditions The SHT7x are shipped in 32 mm tape. These reeled parts in standard option are shipped with 500 units per 13 inch diameter reel. Reels are individually labelled with barcode and human readable labels. 0.46 1.27 (0.018) 5.08 (0.05) (0.2) 0.2 (0.01) 2 (0.08) Figure 17 SHT7x dimensions in mm (inch) Carrier Tape Cover Tape Trailer Tape 300mm minimum Components Leader Tape 500mm minimum Figure 16 Tape configuration and unit orientation 5.2.3 Soldering Information2 Standard wave SHT7x soldering ovens may be used at maximum 235 C for 20 seconds. For manual soldering contact time must be limited to 5 seconds at up to 350 C. After wave soldering the devices should be stored at >74 %RH for at least 24 h to allow the polymer to rehydrate. Please consult the application note "Soldering procedure" for more information. Other packaging options may be available on request. For maximum accuracy do not solder SHT75! www.sensirion.com 1 2 v2.02 July 2004 8/9 SHT1x / SHT7x Relative Humidity & Temperature Sensor System 6 Revision history Date February 2002 June 2002 March 2003 July 2004 Version Page(s) Changes Preliminary 1-9 First public release Preliminary Added SHT7x information Final v2.0 1-9 Major remake, added application information etc. Various small modifications V2.01 1-9 Typos, Graph labeling V2.02 1-9 Improved specifications, added SF1 information, improved wording The latest version of this document and all application notes can be found at: www.sensirion.com/en/download/humiditysensor/SHT1x_SHT7x.htm 7 Important Notices 7.1 Warning, personal injury 7.3 Warranty 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. Failure to comply with these instructions could result in death or serious injury. SENSIRION AG makes no warranty, representation or guarantee regarding the suitability of its product for any particular purpose, nor does SENSIRION AG assume any liability arising out of the application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or incidental damages. "Typical" parameters can and do vary in different applications. All operating parameters, including "Typical" must be validated for each customer applications by customer's technical experts. Should buyer purchase or use SENSIRION AG products for any such unintended or unauthorized application, Buyer shall indemnify and hold SENSIRION AG and its officers, employees, subsidiaries, affiliates and distributors harmless 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 such claim alleges that SENSIRION AG was negligent regarding the design or manufacture of the part. 7.2 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 normal ESD precautions when handling this product. See application note "ESD, Latchup and EMC" for more information. SENSIRION AG reserves the right, without further notice, to change the product specifications and/or information in this document and to improve reliability, functions and design. Copyright(c) 2001-2004, SENSIRION AG. All rights reserved. Headquarters and Sales Office SENSIRION AG Eggbuhlstr. 14 P.O. Box CH-8052 Zurich Switzerland Phone: + 41 (0)44 306 40 00 Fax: + 41 (0)44 306 40 30 e-mail: info@sensirion.com http://www.sensirion.com/ Sensirion humidity sensors are available from: find your local representative at: www.sensirion.com/reps www.sensirion.com v2.02 July 2004 9/9