TECHNICAL 1 DATA TEMPERATURE AND RELATIVE HUMIDITY SENSOR HTS2010SMD Based on a unique capacitive cell for humidity measurement and a Negative Temperature Coefficient (NTC) thermistor for temperature measurement, this dual purpose relative humidity / temperature miniaturized sensor is designed for high volume, cost sensitive applications with tight space constraints. It is useful in all applications where dew point, absolute humidity measurements or humidity compensation are required. MAIN FEATURES Miniature Surface mount SMD package Compatible with automated assembly processes, including wave soldering, water immersion and reflow soldering Full interchangeability with no calibration required in standard conditions HTS2010SMD High reliability and long term stability HUMIDITY SENSOR SPECIFIC FEATURES Instantaneous desaturation after long periods in saturation phase Patented solid polymer structure Suitable for linear voltage or frequency output circuitry RH Fast response time TEMPERATURE SENSOR SPECIFIC FEATURES High quality thermistor Stable T High sensitivity MAXIMUM RATINGS Ratings Symbol (Ta = 25C unless otherwise noted) Value Unit Storage Temperature Tstg - 40 to 100 C Supply Voltage on humidity cell Vs 10 Vac Humidity Operating Range RH 0 to 100 % RH Temperature Operating Range Ta - 40 to 100 C Maximum Electric Power to be supplied (continuous) @ 25C P25 2 mW CHARACTERISTICS Humidity sensor (Ta = 25C, Vs = 5 volts, measurement frequency @ 10 kHz unless otherwise noted) Characteristics Symbol Min. Humidity measuring range RH 1 Nominal capacitance @ 55 % RH* C 177 C/%RH Typ. 180 Max. Unit. 99 % 183 pF 0.34 pF/%RH Long term stability 0.5 %RH/yr Recovery time after 150 hours of condensation 10 s 10 s Averaged Sensitivity from 33 % to 75 % RH Response time (33 to 76 % RH, static, @ 63 %) Humirel Sensor Device Data / HPC008 Rev D April 2001 TECHNICAL 2 DATA CHARACTERISTICS (CONT) Humidity sensor (Ta = 25C, measurement frequency @ 10 kHz unless otherwise noted) Characteristics Symbol Min. Typ. Tcc Temperature coefficient at 55 % RH / 10 to 40C Humidity Hysteresis Vs Leakage current (Vs = 5 volts) Unit. + 0.04 pF/C +/-1.5 % RH +/-2 % RH Deviation to typical curve (see below) (10 % to 90 % RH) Supply voltage Max. 1 5 10 Vac 1 nA Max. Unit. x *Tighter tolerance available on request Temperature sensor Characteristics Symbol Min. Typ. k 10 Nominal resistance @ 25C Beta value : B25/100 B 3600 3730 3800 Temperature measuring range Ta - 40 Nominal Resistance Tolerance* Rn 2 B value tolerance B 3 % Response Time 10 s 100 C 3 % *Tighter tolerance available on request Typical response curve of HTS2010SMD in humidity 205 200 Calibration data are traceable to NIST standards through CETIAT laboratory. capacitance (in pF) 195 190 Measurement frequency : 10 kHz Ta = 25C 185 180 175 170 Polynomial response : 165 160 0 10 20 30 40 50 60 70 80 90 100 C in pF, RH in % Relative Humidity (% RH) Typical temperature output Depending on the needed temperature measurement range and the associated accuracy, we suggest two methods to access to the NTC resistance values. 1 NTC resistance in at temperature T in K NTC resistance in at rated temperature in K Temperature in K B value, material-specific constant of the NTC thermistor Base of natural logarithm (e = 2,71828) The actual characteristic of an NTC thermistor can, however, only be roughly described by the exponential relation, as the material parameter B in reality also depends on temperature. So this approach is only suitable for describing a restricted range around the rated temperature or resistance with sufficient accuracy. 2 For practical applications a more precise description of the real R/T curve may be required. Either more complicated approaches (e.g the Steinhart-Hart equation) are used or the resistance/temperature relation as given in tabulated from. These standardized curves have been experimentally determined with utmost accuracy ; they are aslo available for temperature increments of 1 degree. Humirel Sensor Device Data / HPC008 Rev D April 2001 C -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 R NTC standardized ohm C ohm 262960 194110 144790 109030 82923 63591 49204 38279 30029 23773 18959 15207 12280 10000 8178 35 40 45 50 55 60 65 70 75 80 85 90 95 100 6734 5575 4636 3874 3237 2720 2304 1960 1674 1432 1235 1067 927 809 C -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 R NTC exponential ohm C ohm 52000 40500 31000 24500 19300 15400 12350 10000 8140 35 40 45 50 55 60 65 70 75 80 85 90 95 100 6670 5500 4550 3800 3180 2690 2270 1940 1650 1430 1230 1070 925 810 TECHNICAL 3 DATA SUGGESTED EVALUATION CIRCUIT FOR HUMIDITY FREQUENCY AND TEMPERATURE ANALOG OUTPUTS Relative humidity (Frequency output) This circuit is a typical Astable design for 555. The HTS2010 is used as a variable capacitor and provides an output frequency modulation with relative humidity ranging from 0% to 100%. In this frequency output circuit configuration (for capacitance measurement), R1 unbalances the internal temperature compensation scheme of the 555. It shifts the negative initial temperature coefficient of the 555 to a positive one that matches the humidity sensing chip's temperature coefficient of - 1.4Hz/C. In all cases, R1 should be a 1 % resistor with a maximum of 100ppm temperature coefficient like all other R-C timer resistors. Resistors values Since 555 internal temperature compensation changes from manufacturer to manufacturer, R1 and R2 values should be adapted to device to be used. 555 R1 R2 909k 576k TS555 (STM) 100nF capacitor 523k 7555 (Harris) 1732k 549k LMC555 (National) 1238k 562k TLC555 (Texas) For a frequency of 6660Hz at 55%RH Temperature (voltage output) The temperature measurement is done by a voltage divider, RV2 must be adjusted to get 2.5 V at 25C as temperature measurement. Polarization In order to get better reproducibility during measurement, always connect pin 4 (see the package outline on page 4) to the ground of the circuit. Soldering instructions See application note HPC 034 VO Humirel Sensor Device Data / HPC008 Rev D April 2001 TECHNICAL 4 DATA QUALIFICATION PROCESS HTS2010SMD sensors have been qualified through a complete qualification process taking in account many of the requirements of the MIL STD750 including : Solder heat and solderability Wave soldering at 260C + DI water clean at 45C High Temperature / Humidity Operating Life - 93% RH / 60C for 1000 hours Mechanical shock - 1500 g, 5 blows, 3 directions Low humidity storage life - RH < 10%/23C - 1000 hours Vibration - Variable (F = 100 - 2000Hz), fixed (F = 35Hz) Resistance to immersion in water at ambient temperature and 80C - 160 hours Constant acceleration Marking permanency ESD - Electrostatic Discharge - Human body & Machine model Salt Atmosphere MIL STD750/Method 1041/96 hours Resistance to acid vapors at 75000 ppm for nitric, sulfuric and chlorhydric acids Resistance to many chemicals linked with home appliances/ automative or consumer applications. Temperature Cycling - -40C / +70C PACKAGE OUTLINE HTS2010SMD RECOMMENDED FOOTPRINT All dimensions in mm Scale 1:1 GULL WING (JLEAD option also available). A B C D mm (typical) 6 10 2.7 0.8 Dimension E F G H L 2.54 12.8 0-7 0.2 0.1 ORDERING INFORMATION (MULTIPLE PACKAGE QUANTITY OF 80 PIECES). HTS 2010 SMD : HUMIDITY ANALOG VOLTAGE OUTPUT MODULE SAMPLE KIT OF HTS 2010 IS AVAILABLE THROUGH HUMIREL WEB SITE www.humirel.com email : sales@humirel.com The information in this sheet has been carefully reviewed and is believed to be accurate ; however, no responsability is assumed for inaccuracies. Furthermore, this information does not convey to the purchaser of semiconductor devices any license under the patent rights to the manufacturer. Humirel reserves the right to make changes without further notice to any product herein. Humirel makes no warranty, representation or guarantee regarding the suitability of its product for any particular purpose, nor does Humirel 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. Customer's technical experts must validate all operating parameters, including "Typical" for each customer application. Humirel does not convey any license under its patent rights nor the rights of others. Humirel products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other application intended to support or sustain life, or for any application in which the failure of the Humirel product could create a situation where personal injury or death may occur. Should buyer purchase or use Humirel products for any such unintended or unauthorized application, Buyer shall indemnify and hold Humirel and its officers, employees, subsidiaries, affiliates and distributors harmless against all claims, costs, damages and expenses, and reasonable attomey 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 Humirel was negligent regarding the design or manufacture of the part. Humirel is a registered trademark of Humirel. Humirel Sensor Device Data / HPC008 Rev D April 2001