SDX Series Low cost compensated pressure sensors in DIP package FEATURES GENERAL DESCRIPTION · 0...1 to 0...100 psi · Low cost DIP package · Temperature compensation · Calibrated zero and span · Small size · Low noise · High impedance for low power applications Devices are available to measure absolute, differential and gage pressures from 1 psi (SDX01) up to 100 psi (SDX100). The absolute (A) devices have an internal vacuum reference and an output voltage proportional to absolute pressure. Medical equipment · Computer peripherals · Pneumatic controls · HVAC Scale: All SDX devices are calibrated for span to within 3.5 % and provide an offset (zero pressure output) of ±1 mV max. These parts were designed for low cost applications where the user can typically provide fine-adjustment of zero and span in external circuitry. For higher accuracies, refer to the SDX-A series datasheet. The SDX devices feature an integrated circuit sensor element and laser trimmed thick film ceramic housed in a compact solvent resistant case. This package provides excellent corrosion resistance and isolation to external package stresses. The DIP package EQUIVALENT CIRCUIT 1 cm ½ inch also provides convenient mounting and pressure ports for ease of use with standard plastic tubing for pressure connection. The output of the bridge is ratiometric to the supply voltage and operation from any D.C. supply voltage up to +20 V is acceptable. APPLICATIONS · The SDX series sensors will provide a very cost effective solution for pressure applications that require small size plus performance. These internally calibrated and temperature compensated sensors give an accurate and stable output over a 0 to 50°C temperature range. This series is intended for use with non-corrosive, non-ionic working fluids such as air and dry gases. ELECTRICAL CONNECTION TOP VIEWS Pin 1 identified by chamfered corner Vs P2 +Vs 4 Pin 1 identified by chamfered corner 1 out + out - GND GND out - out + 1 out + 1 P1 +Vs 4 P1 GND +Vs P2 out - 4 Vent hole SDX...G2 + - Note: The polarity identicated is for pressure applied to SDX...G2: SDX...A2: SDX...D4: SDX...A4: June 2008 / 062 SDX...A2 P2 P1 P2 P1 (backward gage) (forward gage) (backward gage) (forward gage) SDX...D4 out GND out + 1 P1 +Vs 4 SDX...A4 1/4 www.sensortechnics.com SDX Series Low cost compensated pressure sensors in DIP package PRESSURE SENSOR CHARACTERISTICS (all devices) Maximum ratings Environmental specifications Supply voltage VS +20 VDC Maxium pressure on any port Temperature ranges Compensated Operating Storage Humidity limits 150 psig Lead temperature (soldering 4 sec.) 250°C 0 to 50°C -40 to +85°C -55 to +125°C 0 to 100% RH STANDARD PRESSURE RANGES Part number Operating pressure Proof pressure11 SDX01... SDX05... SDX15A... SDX15G2, ...D4 SDX30A... SDX30G2, ...D4 SDX100A... SDX100G2, ...D4 0 - 1 psig/d 0 - 5 psig/d 0 - 15 psia 0 - 15 psig/d 0 - 30 psia 0 - 30 psig/d 0 - 100 psia 0 - 100 psig/d 20 psi 20 psi 30 psi 30 psi 60 psi 60 psi 150 psi 150 psi Full-scale span1,2 Min. 17.37 mV 57.9 mV 86.85 mV 86.85 mV 86.85 mV 86.85 mV 96.5 mV 96.5 mV Typ. 18 mV 60 mV 90 mV 90 mV 90 mV 90 mV 100 mV 100 mV Max. 18.63 mV 62.1 mV 93.15 mV 93.15 mV 93.15 mV 93.15 mV 103.5 mV 103.5 mV * Maximum pressure above which causes permanent sensor failure. COMMON PERFORMANCE CHARACTERISTICS1 Characteristic Zero pressure offset Combined linearity and hysteresis3 Temperature effect on span (0 to 50°C)4 Temperature effect on offset (0 to 50°C)4 Repeatability5 Input impedance6 Output impedance7 Common-mode voltage8 Response time9 Long term stability of offset and span10 Min. Typ. Max. Unit -1.0 ------------1.3 ----- 0 ±0.2 ±0.4 ±0.2 ±0.2 4.0 4.0 3.0 100 ±0.1 +1.0 ±1.0 ±2.0 ±1.0 ±0.5 ----5.0 ----- mV %FSO %FSO mV %FSO kΩ kΩ VDC µsec mV Specification notes: 1. Reference conditions: supply voltage, VS = 12 VDC, TA = 25°C, common-mode line pressure = 0 psig, pressure applied to port 2. For absolute devices only, pressure is applied to port 1 and the output polarity is reversed. 2. Span is the algebraic difference between the output voltage at full-scale pressure and the output at zero pressure. Span is ratiometric to the supply voltage. 3. See Definition of Terms. Hysteresis - the maximum output difference at any point within the operating pressure range for increasing and decreasing pressure. 4. Maximum error band of the offset voltage and the error band of the span, relative to the 25°C reading. 5. Maximum difference in output at any pressure with the operating pressure range and temperature within 0 to +50°C after: a) 100 temperature cycles, 0 to + 50°C b) 1.0 million pressure cycles, 0 psi to full-scale span 6. Input impedance is the impedance between pins 2 and 5. 7. Output impedance is the impedance between pins 1 and 3. 8. This is the common-mode voltage of the output arms (pins 1 and 3) for VS = 12 VDC. 9. Response time for a 0 psi to full-scale span pressure step change, 10 to 90 % rise time. 10. Long term stability over a one year period. 11. Maximum pressure at any port is the maximum operating plus common-mode pressure which can be applied. The proof pressure for the forward gage of all devices in the D4-package is the specified value or 100 psi, whatever is less. June 2008 / 062 2/4 www.sensortechnics.com SDX Series Low cost compensated pressure sensors in DIP package PHYSICAL DIMENSIONS SDX...G2, ...A2 0.470 (11.94) 0.550 (13.97) 0.105 (2.67) 0.315 (8.00) typ. 0.280 (7.11) typ. 0.190 (4.83) typ. compensation circuit 0.020 (0.51) typ. 0.600 (15.24) typ. mass: 2 g 0.01 (0.25) 0.110 (2.79) typ. 0.100 (2.54) typ. dimensions in inches (mm) SDX...D4, ...A4 1 P1 0.470 (11.94) 4 P2 version SDX...A4 without port P2 0.550 (13.97) Ø 0.090 (2.29) typ. 0.300 (7.62) 0.135 (3.43) 0.250 (6.35) 0.430 0.335 (10.92) typ. (8.50) typ. compensation circuit 0.600 (15.24) typ. mass: 2 g June 2008 / 062 0.120 (3.05) typ. 0.010 (0.25) typ. 0.020 (0.51) typ. 0.110 (2.79) typ. 0.100 (2.54) typ. dimensions in inches (mm) 3/4 www.sensortechnics.com SDX Series Low cost compensated pressure sensors in DIP package GENERAL DISCUSSION USER CALIBRATION The SDX series devices give a voltage output which is directly proportional to applied pressure. The gage devices will give an increasing positive going output when increasing pressure is applied to the pressure port. The absolute device will give a decreasing output when increasing pressure is applied to the port. The devices are ratiometric to the supply voltage and changes in the supply voltage will cause proportional changes in the offset voltage and full-scale span. The SDX devices are fully calibrated for offset and span and should therefore require little user adjustment in most applications. For more precise span and offset adjustments, contact the factory. PNEUMATIC INTERFACE The DIP also provides convenient mounting and pressure ports for ease of use with standard 1/16" ID, 1/8" OD, 1/32" wall, flexible plastic tubing for pressure connection. VACUUM REFERENCE (absolute devices) Absolute sensors have a hermetically sealed vacuum reference chamber. The offset voltage on these units is therefore measured at vacuum, 0 psia. Since all pressure is measured relative to a vacuum reference, all changes in barometric pressure or changes in altitude will cause changes in the device output. MEDIA COMPATIBILITY The small tubing has several advantages over larger tubing commonly used with pressure sensors: 1) The tubing can be formed in a much smaller radius without kinking. 2) The tubing is easier to handle. 3) The tubing is available in a variety of colors such as clear, white, yellow, blue, green, etc. to enable color coding of pneumatic circuits with multiple pressure sensors in the same way that wiring harnesses are color coded in electrical circuits. This greatly simplifies troubleshooting. 4) Less stress is placed on the pressure sensor package resulting in less potential for offset shift. 5) Less physical space is required for the small tubing. 6) The lower volume of air in the small tubing results in faster pressure sensor response. SDX devices are compatible with most non-corrosive gases. Because the circuitry is coated with a protective silicon gel, many otherwise corrosive environments can be compatible with the sensors. Fluids must generally be compatible with silicon gel, plastic, RTV, silicon, and glass for use with the gage devices (only). For questions concerning media compatibility, contact the factory. MECHANICAL AND MOUNTING CONSIDERATIONS The DIP housing is designed for convenient pressure connection and easy PC board mounting. For pressure attachment tygon and silicon tubing is recommended. APPLICATION INFORMATION The application information for the SCX series is also applicable to the SDX series. ORDERING INFORMATION Operating pressure Order number Absolute devices Gage devices Gage/differential devices 0 - 1 p si SDX01G2 S D X 01D 4 0 - 5 p si SDX05G2 S D X 05D 4 0 - 1 5 p si S D X 15A 2 S D X 15A 4 SDX15G2 S D X 15D 4 0 - 3 0 p si S D X 30A 2 S D X 30A 4 SDX30G2 S D X 30D 4 0 - 1 0 0 p si S D X 100A 2 S D X 100A 4 SDX100G2 S D X 100D 4 SenSym and Sensortechnics reserve the right to make changes to any products herein. SenSym and Sensortechnics do not assume any liability arising out of the application or use of any product or circuit described herein, neither does it convey any license under its patent rights nor the rights of others. June 2008 / 062 4/4 www.sensortechnics.com