SDP1108/SDP2108 Low Differential Pressure Sensor with fast response time - For medical ventilators (ICU and home care) - High sensitivity below 10 Pa to measure small volume flow (neonatal) - Fast response time for efficient trigger function - Unsurpassed performance thanks to CMOSens(R) technology - Offset and hysteresis free - Fully calibrated and temperature compensated - Not sensitive to the mounting orientation and vibrations SDPx108 Product Summary The SDPx108 sensor family is a differential pressure sensor for air based on the successful SDP1000/ SDP2000 sensor from Sensirion AG. The response time of the SDPx108 has been optimized for medical ventilation applications. Mounted in a rugged, chemically inert PPS housing the SDPx108 differential pressure sensors feature a unique dynamic range, zero offset and unsurpassed long term stability. This makes it an ideal fit for demanding yet cost sensitive OEM applications in medical and HVAC equipment. The SDPx108 is fully RoHS compliant. The SDPx108 is supplied with 5.0 V and provides a 0.25...4.0 V output. Although the output of the sensor is analog, the internal linearization and temperature Its leading performance is based on Sensirion's proprietary CMOSens(R) sensor technology which combines the sensor element with amplification and A/D conversion on one single silicon chip. The differential pressure is measured by a thermal sensing element. In contrast to other thermal differential pressure sensors only a very small amount of air is required. This leads to a reliable operation even under harsh conditions. In comparison to membrane and piezo-resistive based sensors the SDPx108 differential pressure sensors show an extended measurement range, better offset stability and improved reproducibility even at lowest pressure ranges. In addition the SDPx108 is robust against pressure bursts and shows no sensitivity to the mounting orientation. www.sensirion.com Version 2 - February 2013 DIGITAL Linearization and Temperature compensation Differential pressure Sensor CMOSens(R) SENSOR CHIP D/A converter Medical applications: * Homecare ventilation * Intensive care ventilation (ICU) * Other Memory Block Diagram A/D converter Applications compensation is performed digitally. This results in a superior accuracy, outstanding resolution (up to 0.05 Pa), and lowest temperature dependence. Pin 3: OUT 0.25 V to 4 V Pin 2: GND Pin 1: VDD 5.0 V 1/7 1 Sensor Output Characteristics1 The SDPx108-R provides a fully calibrated voltage output. To enhance resolution and accuracy at very low differential pressures, the SDPx108 standard version (SDPx108-R) comes with a root-square output characteristics. SDPx108-R output voltage [V] 3.75 3.25 2.75 2.25 For high-quantity OEM applications, other ranges and output characteristics can be realized. E.g. linear output and a bidirectional measurement range is possible. Please contact Sensirion for further information. 1.75 1.25 0.75 0.25 0 20 40 60 80 differential pressure [% FS] 100 Use this formula to convert the sensor output into Output _ Voltage - 0.25V Diff. Press.[ Pa ] = FS [Pa ] physical value. 3.75V 2 1Calibration conditions apply unless otherwise noted: 23C and pabsolute = 966 mbar, dry air, VDD = 5.000 V. FS is 500Pa for the SDP1108 and 3500 Pa for the SDP2108. 2 Specifications Table 1: SDPx108-R Sensor specifications1 SDP1108-R Parameter Typ Max Min 0.25 - 4 0.25 4 Volts 0 - 500 0 3500 Pa 0 - 2 0 14 Inch water 20% FS to 100% FS - 1.0 2.0 - 1 2 % Measured Value4 0 to 20% FS - 100 to 500 Pa - 0.4 40 0.06 1.0 - zero2 0.2 15 0.01 0.3 - 0.2 20 0.1 0.3 0.4 50 0.6 1.0 % Full Span5 mV Pa % Measured Value 0 to 100 Pa - 0.05 0.2 - 0.06 0.2 % Full Span5 - 0 0.1 - 0 0.3 Pa / year 0 to 100 % FS - 0.03 0.05 - 0.03 0.05 % Measured Value4 / C zero - 1 2 - 1 3 mV/C 6.6 8.0 10.1 6.6 8.0 10.1 ms 17 20 24 17 20 24 Hz Accuracy3 Repeatability Null drift per year6 Additional error over temperature7 (T 23C) time(8) Cut off frequency of internal filter - Typ Unit Min Measurement range Response SDP2108-R Max 1 Calibration conditions apply unless otherwise noted: 23C and pabsolute = 966 mbar, dry air, VDD = 5.000 V between the zero point (offset) of different sensors measured under the same conditions (e.g. same supply voltage, temperature, ...) 3 Include deviations due to linearity, hysteresis, and repeatability 4 % Measured value = (SDPx108 output [Pa] - output of reference instrument [Pa]) / output of reference instrument [Pa]. 5 Full span is defined as 3750 mV / 500 Pa for SDP1108 and 3750 mV / 3500 Pa for the SDP2108. 6 Drift over time due to aging, pressure cycles... Test results can be provided. 7 The additional error due to temperature variation is temporary. Once the sensor is back to the calibration temperature, the shift disappears (no hysteresis). 8 Tau= 0 to 63%, filter response time = 8ms. For faster response time, contact Sensirion. 2 Variance www.sensirion.com Version 2- February 2013 2/7 Table 2: Additional sensor specifications. Parameter Media Calibration1 Air, N2 - for other gases contact Sensirion AG. Media Compatibility Operating Conditions2: - Temperature - Humidity Ambient storage conditions3 Air, N2, O2 Orientation sensitivity below zero point accuracy Admissible overpressure (short term) 1 bar (14.5 PSI) Burst Pressure Capability 2 bar (29 PSI) Weight 14 g Protection Class IP 20 Wetted materials Glass (silicon nitride, silicon oxide), Silicon, PPS (Polyphenylene Sulfide), PEEK (Polyetheretherketone), FR4, Silicone as static sealing, Epoxy, Gold Electromagnetic compatibility EN 61000-4-2 Lead free ROHS compliant. 1 Sensors Air discharge (ESD) 2 kV are calibrated for a specific gas, please contact Sensirion when you employ different gases than the specified. 2Condensation 3For -10 C ... +60 C / 14F ... 140 F non-condensing -40 C ... +80 C / -40F ... 176 F of liquids or dust on the sensor membrane might lead to sensor offset. Please consult our application notes on www.sensirion.com. maximum 2 weeks This leads to the following correction factors: 2.1 Temperature Compensation The SDPx108 differential pressure sensors feature a sophisticated built-in temperature compensation circuit. The temperature is measured on the CMOSens(R) chip by means of a PTAT bandgap reference temperature sensor. Its data is fed into a compensation circuit which is also integrated on the CMOSens(R) sensor chip. No external temperature compensation is therefore required. 2.2 Altitude Correction The SDPx108 differential pressure transducers achieve their unsurpassed performance by using a dynamic measurement principle: An applied differential pressure forces a small air flow through the SDPx108, which measures this air flow. The sensor signal is dependant on the ambient air density. The temperature effect on density is compensated by internal intelligence (see Paragraph 2.3). Effects on density due to a change of ambient pressure, typically a change of altitude above sea level, can be compensated using a correction factor according to the following equation: Dpeff = Dpsensor * Pcal / Pamb Where Dpeff is the effective differential pressure, Dpsensor the differential pressure indicated by the SDPx108, Pcal the absolute pressure during calibration (966 mbar) and Pamb the actual ambient absolute pressure. www.sensirion.com Table 3: Altitude correction factors. Altitude [meter] 0 250 425 500 750 1500 2250 3000 Ambient Pressure (Pamb) [mbar] 1013 984 966 958 925 842 766 697 Correction Factor Pcal / Pamb 0.95 0.98 1.00 1.01 1.04 1.15 1.26 1.38 Example: The SDP1108 is used at 750 m above sea level. The output of the SDP1108 shows 0.5 V, which corresponds to Dpsensor = 33.3 Pa. Taking into account the correction factor Pcal / Pamb = 1.04 the effective differential pressure Dpeff is 33.3 Pa * 1.04 = 34.6 Pa. Note: In many medical and HVAC applications such as filter monitoring, fan/ventilator control or air flow measurement the described effect is actually welcome since at the end the mass flow and not volume flow is the effective value to control. Version 2 - February 2013 3/7 3 Physical Dimensions and Mounting Information 3.1 Housing The SDPx108 differential pressure transducers are mounted in chemically inert PPS housing. The rugged package has been designed to withstand continuous overpressures of at least 1 bar (14.5 PSI). Burst pressure is > 2 bar (29 PSI) 5.2 5.4 (0.205) The physical dimensions and mounting information is given in Figure 1 and 2. A A 16.0 (0.630) (0.213) 3.4 (0.134) No Components inside this Area C H 30.5 (1.200) G I Lo 44.0 (1.732) Hi F B 2.54 (0.100) Pin# 1 2 3 D 1.8 (0.071) 30.0 (1.181) Pin# 1 2 3 E 22.1 18.3 (0.870) (0.720) 13.1 (0.516) B SDP100000206-10033-250-001 Function VDD (5 Vdc) Ground OUT (0.25...4 Vdc) Figure 1: Pin out and physical dimensions in mm (inch). The drawing is not to scale. Dim. [mm] [inch] [mil] A 3.00 0.118 118 B C D E F G H I 3.30 1.20 10.20 28.20 2.54 0.60 0.50 22.70 0.130 0.047 0.402 1.110 0.100 0.024 0.020 0.894 130 47 402 1110 100 24 20 894 Figure 2: SDPx108 PCB footprint. The drawing is not to scale. 3.2 Soldering Instructions The SDPx108 differential pressure sensors can be wave soldered. Direct reflow soldering is not recommended since it may affect the accuracy. www.sensirion.com If reflow soldering is required Sensirion recommends to use an SMD connector (e.g. type Samtec SSM-103-LSV) and to mount the SDPx108 after soldering. Version 2 - February 2013 4/7 3.3 Connecting Hose Sensirion recommends a hose with an inner diameter of 3.18 to 3.8mm (1/8 to 3/20 inch). Due to the dynamic measurement principle, a small air flow is required (Figure 3) which leads to a dependence on the length of the hose (Table 4). Tubes up to 1 m show less than 2 % error of the measured value (Table 4). Table 4: Influence of the length of the connecting hose on the accuracy (using 4 mm inner diameter). Deviation is given in % of the measured value. Example SDP1108: a 500 Pa difference pressure is shown as 492.5 Pa when using 1 m tube with 4 mm inner diameter. Hose length Figure 3: Typical air flow through the SDP1108. Please note: 1 scc/min = 1 cm3/min at 0C and 1013 mbar pressure (1 sccm = 0.001 norm liter). SDP1108 SDP2108 @FS @0.5 FS @FS @0.5FS 0.5 m (20 inch) -0.75% -0.95% -0.06% -0.07% 1.0 m (40 inch) -1.5% -1.9% -0.12% -0.14% 2.0 m (80 inch) -3.0% -3.8% -0.24% -0.28% Table 5: Maximum flow through the sensor element. Mass flow through sensor element: 4 SDP1108-R SDP2108-R 123 sccm (@ 500 Pa) 66 sccm (@3500 Pa) Electrical Specifications 4.1 Power Supply The SDPx108 differential pressure sensors require a stable voltage supply of 5.0 V. The requirements for the electrical supply are specified in Table 5. The resistive load at the output pin should be larger than 20 kOhm. The capacitive load at the output pin must not be larger than 200 pF. If the design shows a larger capacity at the output pin an additional resistor is required in series at the output (e.g. 620 Ohm). 4.2 Voltage Output The SDP1108 features a voltage output from 0.25 V to 4.0 V. An output voltage below 0.25 V indicates a negative differential pressure (not calibrated). Table 6: SDPx108 electrical characteristics. Parameter Conditions Min. Power Supply Voltage VDD Operating Current 4.75 5 V, no load, zero flow Output capacitive load Cload Recommended load Rload www.sensirion.com 20 Version 2 - February 2013 Typ. Max. Units 5.0 5.25 VDC 5.1 6 mA 20 200 pF 100 k 5/7 5 Ordering Information When ordering please refer to the following part names and article numbers. For the latest product information and local distributor check out Sensirion's website on http://www.sensirion.com Part Name Article Number SDP1108-R 1-100339-03 SDP2108-R 1-100729-03 Revision history Date Revision Author Changes October 2008 June 2010 V1.0 V1.1 PHA DAT February 2013 V2 ANB Initial release SDP2108 launched, New Item Number (see product change notification PCN 081015), block diagram (page 1), minor changes Updated product number. Minor layout updates. www.sensirion.com Version 2 - February 2013 6/7 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 (including death). 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. 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) 2001-2013, SENSIRION. CMOSens(R) is a trademark of Sensirion All rights reserved 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. RoHS and WEEE Statement The SDPx108 Series complies with requirements of the following directives: * * EU Directive 2002/96/EC on waste electrical and electronic equipment (WEEE), OJ13.02.2003; esp. its Article 6 (1) with Annex II. EU Directive 2002/95/EC on the restriction of the use of certain hazardous substances in electricaland electronic equipment (RoHS), OJ 13.02.2003; esp. its Article 4. 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 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 2 - February 2013 7/7 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Sensirion: SDP1108-R SDP2108-R