MICS-6814 SGX | Alldatasheet

Document overview

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Technical content

Features

  • Smallest footprint for compact designs (5 x 7 x 1.55 mm)
  • Robust MEMS sensor for harsh environments
  • High-volume manufacturing for low-cost

applications

  • Short lead-times Detectable gases
  • Carbon monoxide CO 1 – 1000ppm
  • Nitrogen dioxide NO 2 0.05 – 10ppm
  • Ethanol C 2H5OH 10 – 500ppm
  • Hydrogen H 2 1 – 1000ppm
  • Ammonia NH 3 1 – 500ppm
  • Methane CH 4 >1000ppm
  • Propane C 3H8 >1000ppm
  • Iso-butane C 4H10 >1000ppm 0.01 0.10 1.00 10.00 100.00 0.01 0.1 1 10 100 Concentration [ppm] Rs/R0 Hydrogen NO NO2 RED sensor, continuous power ON, 25°C, 50% RH OX sensor, continuous power ON, 25°C, 50% RH 0.01 0.10 1.00 10.00 0.1 1 10 100 1000 10000 100000 Concentration [ppm] Rs/R0 CO Ethanol Hydrogen Methane Propane Iso-butane Ammonia 0.01 0.10 1.00 10.00 0.1 1 10 100 1000 10000 100000 Concentration [ppm] Rs/R0 CO Ethanol Hydrogen Methane Propane Iso-butane Ammonia H2S Page 1 of 5 0.0 0.1 1.0 10.0 1 10 100 1000 10000 100000 Concentration [ppm] Rs/R0 Hydrogen Ethanol Ammonia Propane Iso-butane NH3 sensor, continuous power ON, 25°C, 50% RH

RED sensor Symbol Typ Min Max Unit Sensing resistance in air (see note 1) R 0 - 100 1500 kΩ Typical CO detection range FS 1 1000 ppm Sensitivity factor (see note 2) S 60 - 1.2 50 - Performance OX sensor Characteristic OX sensor Symbol Typ Min Max Unit Sensing resistance in air (see note 1) R 0 - 0.8 20 kΩ Typical NO 2 detection range FS 0.05 10 ppm Sensitivity factor (see note 3) S R - 2 - - MiCS-6814 1143 rev 8 Notes: 1. Sensing resistance in air R 0 is measured under controlled ambient conditions, i.e. synthetic air at 23 ±5°C and 50 ± 10% RH for RED sensor and synthetic air at 23 ±5°C and ≤ 5% RH for OX sensor. Sampling test. 2. Sensitivity factor is defined as Rs in air divided by Rs at 60 ppm CO. Test conditions are 23 ± 5°C and 50 ± 10% RH. Indicative values only. Sampling test. 3. Sensitivity factor is defined as Rs at 0.25 ppm NO 2, divided by Rs in air. Test conditions are 23 ± 5°C and ≤ 5% RH . Indicative values only. Sampling test. 4. Sensitivity factor is defined as Rs in air divided by Rs at 1ppm of NH 3. Test conditions are 23 ± 5°C and 50 ± 10% RH. Indicative values only. Sampling test. Page 2 of 5 Performance NH3 sensor Characteristic OX sensor Symbol Typ Min Max Unit Sensing resistance in air (see note 1) R 0 - 10 1500 kΩ Typical NH 3 detection range FS 1 300 ppm Sensitivity factor (see note 4) S R - 1.5 15 -

Power circuit and measurement circuit Parameter RED sensor/OX sensor/NH3 sensor Symbol Typ Min Max Unit Heating power P H 76/43/66 71/30/60 81/50/73 mW Heating voltage V H 2.4/1.7/2.2 - - V Heating current I H 32/26/30 - - mA Heating resistance at nominal power RH 74/66/72 66/59/64 82/73/80 Ω Rating Symbol Value / Range Unit Maximum heater power dissipation P H 88 mW Maximum sensitive layer power dissipation Ps 8 mW Voltage supplyHeating current Vsupply 4.9 – 5.1 V Relative humidity range RH 5 – 95 %RH Ambient operating temperature Tamb -30 – 85 °C Storage temperature range Tsto -40 – 120 °C Storage humidity range RHsto 5 - 95 %RH MiCS-6814 1143 rev 8 MiCS-6814 with measurement circuit (top view) The example above shows the principle to read a resistance between 1 kOhms and 2MOhms with a 8bit A/D converter. Depending on the application and on the precision of the A/D converter, a single load resistor of 56 kOhms may be sufficient. Rload must be 820 Ohms at the lowest in order not to damage the sensitive layer. MiCS-6814 with recommended supply circuit (top view) R1 is 130 Ohms, R2 is 820 Ohms and R3 is 27 Ohms. These resistors are necessary to obtain the right temperatures on the three independent heaters while using a single 5 V power supply. The resulting voltages are typically VhRED = 2.4 V, VhOX = 1.7 V and VhNH3 = 2.2 V. Page 3 of 5

Package outline dimensions The package is compatible with SMD assembly process. Operating conditions MiCS-6814 1143 rev 8 Sensor configuration The silicon gas sensor structure consists of an accurately micro machined diaphragm with an embedded heating resistor and the sensing layer on top. The MiCS-6814 includes three sensor chips with independent heaters and sensitive layers. One sensor chip detects oxidising gases (OX) , the other sensor detects reducing gases (RED) and the other detects NH 3. The internal connections are shown above. Pin Connection A Rs2 B Rh1 RED, Rs1 RED C Rh1 NH 3 D Rs1 NH 3 E Rh2 NH 3 F Rs2 NH 3 G Rh2 RED H Rs2 RED J Rh1 OX, Rs1 OX K Rh2 OX MiCS-6814 configuration (bottom view) Page 4 of 5

SGX Sensortech, Courtils 1 CH-2035 Corcelles-Cormondrèche Switzerland www.sgxsensortech.com For more information please contact: info.em@sgxsensortech.com Power circuit The two resistors (82 ohm for RED and 51+82 ohm for OX) are necessary to obtain the right temperatures on the two independent heaters while using a 5V power supply. Packaging The sensors are packaged in a tape and reel for expedition. The sensors are placed in a carrier type. The dimensions of the cavity are 5.5 x 7.5 x 2.55 mm (the tolerance is +/- 0.2 mm). The outside dimension of the reel is either 178 +- mm (for a maximum of 700 sensors ) or 330 + 0.25 / -4 mm (for a maximum of 2000 sensors). MiCS-6814 1143 rev 8 Whilst SGX sensortech has taken care to ensure the accuracy of the information contained herein it accepts no responsibility for the consequences of any use thereof and also reserves the right to change the specification of goods without notice. SGX sensortech accepts no liability beyond the set out in its standard conditions of sale in respect of infringement of third party patents arising from the use of tubes or other devices in accordance with information contained herein. Page 5 of 5 IMPORTANT PRECAUTIONS: Read the following instructions carefully before using theMiCS-6814 described here to avoid erroneous readings and to prevent the device from permanent damage.

  • The sensor must be reflow soldered in a neutral atmosphere,without soldering flux vapours.
  • The sensor must not be exposed to high concentrations of organic solvents, silicone vapours or cigarette- smoke in order to avoid poisoning the sensitive layer.
  • Heater voltage above the specified maximum rating will destroy the sensor due to overheating.
  • This sensor is to be placed in a filtered package that protects it against water and dust projections.
  • SGX sensortech strongly recommends using ESD protection equipment to handle the sensor.