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 technology Offset and hysteresis free Fully calibrated and temperature compensated Not sensitive to the mounting orientation and vibrations SDPx108 Product Summary compensation is performed digitally. This results in a The SDPx108 sensor family is a differential pressure superior accuracy, outstanding resolution (up to 0.05 Pa), sensor for air based on the successful SDP1000/ and lowest temperature dependence. SDP2000 sensor from Sensirion AG. The response time of the SDPx108 has been optimized for medical Its leading performance is based on Sensirions proprietary ventilation applications. CMOSens sensor technology which combines the sensor element with amplification and A/D conversion on one Mounted in a rugged, chemically inert PPS housing the single silicon chip. The differential pressure is measured by SDPx108 differential pressure sensors feature a unique a thermal sensing element. In contrast to other thermal dynamic range, zero offset and unsurpassed long term differential pressure sensors only a very small amount of stability. This makes it an ideal fit for demanding yet cost air is required. This leads to a reliable operation even sensitive OEM applications in medical and HVAC under harsh conditions. In comparison to membrane and equipment. piezo-resistive based sensors the SDPx108 differential The SDPx108 is fully RoHS compliant. pressure sensors show an extended measurement range, better offset stability and improved reproducibility even at The SDPx108 is supplied with 5.0 V and provides a lowest pressure ranges. In addition the SDPx108 is robust 0.254.0 V output. Although the output of the sensor is against pressure bursts and shows no sensitivity to the analog, the internal linearization and temperature mounting orientation. Applications Block Diagram Medical applications: Homecare ventilation Pin 3: OUT Intensive care ventilation (ICU) CMOSens 0.25 V to 4 V SENSOR CHIP Other Pin 2: GND Pin 1: V 5.0 V DD www.sensirion.com Version 2 February 2013 1/7 Differential pressure Sensor A/D converter DIGITAL Linearization and Temperature compensation D/A Memory converter 1 1 Sensor Output Characteristics The SDPx108-R provides a fully calibrated voltage SDPx108-R output. To enhance resolution and accuracy at very 3.75 low differential pressures, the SDPx108 standard 3.25 version (SDPx108-R) comes with a root-square 2.75 output characteristics. 2.25 For high-quantity OEM applications, other ranges and output characteristics can be realized. E.g. 1.75 linear output and a bidirectional measurement 1.25 range is possible. Please contact Sensirion for 0.75 further information. 0.25 0 20 40 60 80 100 differential pressure % FS 2 Output Voltage - 0.25V Use this formula to convert the sensor output into Diff. Press. Pa = FS Pa physical value. 3.75V 1 Calibration conditions apply unless otherwise noted: 23C and p = 966 mbar, dry air, V = 5.000 V. FS is 500Pa for the SDP1108 and absolute DD 3500 Pa for the SDP2108. 2 Specifications 1 Table 1: SDPx108-R Sensor specifications SDP1108-R SDP2108-R Unit Parameter Min Typ Max Min Typ Max 0.25 - 4 0.25 4 Volts Measurement range 0 - 500 0 3500 Pa 0 - 2 0 14 Inch water 4 20% FS to 100% FS - 1.0 2.0 - 1 2 % Measured Value 5 0 to 20% FS - 0.2 0.4 - 0.2 0.4 % Full Span 3 Accuracy 15 40 20 50 mV 2 zero - - 0.01 0.06 0.1 0.6 Pa 100 to 500 Pa - 0.3 1.0 - 0.3 1.0 % Measured Value Repeatability 5 0 to 100 Pa - 0.05 0.2 - 0.06 0.2 % Full Span 6 Null drift per year - 0 0.1 - 0 0.3 Pa / year 4 0 to 100 % FS - 0.03 0.05 - 0.03 0.05 % Measured Value / C Additional error over 7 temperature (T 23C) zero - 1 2 - 1 3 mV/C (8) Response time 6.6 8.0 10.1 6.6 8.0 10.1 ms Cut off frequency of internal filter 17 20 24 17 20 24 Hz 1 Calibration conditions apply unless otherwise noted: 23C and p = 966 mbar, dry air, V = 5.000 V absolute DD 2 Variance 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. www.sensirion.com Version 2- February 2013 2/7 output voltage V