Digital Output Pressure Sensors Enhanced Digital Output Sensors Features * 5" H2O to 100psi Pressure Ranges * All Combined Errors Over Temperature Less Than 0.1%, Typical * Wide -20 to 85C Compensated Temperature Range * Electrically Compatible to All Sensors GA142 Series * Enhanced Dual Serial Interface Mode Applications * Medical Instrumentation * Environmental Controls * HVAC * Meteorology General Description The Digital Output pressure sensors are based upon a proprietary surface mapping technology to produce a fully digital output that virtually eliminates all repeatable errors over temperature and pressure. This series provides a 12 bit digital serial output (14 bit in High Resolution Mode) with superior offset, span and linearity characteristics. The output is SPI and MICROWIRE/PLUS(R) compatible as well as fully compatible with the All Sensors GA142 Series sensors. In addition to synchronous communications, the Digital Output pressure sensors incorporates a bi-directional, TTL level, asynchronous serial interfaces mode (hardware selectable 9,600 or 19,200 baud). This mode includes a command set that allows the host to interrogate the sensor for model information, pressure range, serial number, pressure units and conversion factor. The command set also allows the host to select a high resolution output mode, make minor adjustments to offset and has an addressable feature that alows multiple sensors to be tied to the same interface buss. This series is intended for use with non-corrosive, non-ionic working fluids such as air, dry gases and the like. All signals are 5V TTL/CMOS compatible. Physical Dimensions Pin Descriptions Pin Label 0.25 (6.4) Pin Size 0.010 x 0.020 (0.25 x 0.50) 0.10 Typical (2.54) 0.174 to 0.190 (4.4 to 4.8) Pin 1 2 3 4 5 6 0.21 (5.3) 1 A 1.08 (27.4) 0.63 (16.0) 0.48 (12.2) 0.55 (14.0) NOTES: 1) Dimensions in inches (millimeters) Vcc +5V power supply input 2 Data/SI Data output for synchronous mode. Serial in for asynchronous mode. 3 Clock/SO Clock output for synchronous mode. Serial out for asynchronous mode. 4 Ready/Mode Ready output for synchronous mode. Selects asynchronous mode when held low during reset. 5 Convert/BR Convert input for synchronous mode. Selects one of two baud rates for asynchronous mode (low=9,600, high=19,200). 6 Ground Ground for power and signals 0.414 (10.5) B 0.80 (20.3) 0.85 (21.6) 1.10 (27.9) 2-19 Description 1 2 Absolute Maximum Ratings Environmental Specifications 7Vdc Supply Voltage (Vcc) Voltage on Any Pin with Respect to Gnd 250C Lead Temperature (soldering 2-4 sec.) -20 C to +85 C Compensated Temperature 50 psig Common-mode pressure +4.75Vdc to +5.25Vdc Operating Voltage -0.6 to Vcc+0.6V Operating Temperature -25 to +90 C Storage Temperature -40 to 125 C 0 to 95% RH (non condensing) Humidity Limits Standard Pressure Ranges Part Number Operating Pressure Units 5 INCH-D-DO 10 INCH-D-DO 1 PSI-D-DO FSO (2) Digital Span (4) Proof Pressure Burst Pressure -5 to 5 inH2O 5 1 200 inH2O 300 inH2O -10 to 10 inH2O 10 1 200 inH2O 300 inH2O -1 to 1 PSI 1 1 200 inH2O 300 inH2O -5 to 5 PSI 5 1 10 PSI 30 PSI -15 to 15 PSI 15 1 60 PSI 120 PSI 15 PSI-A-DO 0 to 15 PSIA 15 2 60 PSI 120 PSI 30 PSI-D-DO -30 to 30 PSI 30 2 90 PSI 150 PSI 30 PSI-A-DO 0 to 30 PSIA 30 2 90 PSI 150 PSI 5 PSI-D-DO 15 PSI-D-DO 100 PSI-D-DO -100 to 100 PSI 100 2 200 PSI 250 PSI 100 PSI-A-DO 0 to 100 PSIA 100 2 200 PSI 250 PSI General Performance Characteristics (All Models) Parameter (1) Minimum Nominal Maximum Units 12 -- -- Bit Conversion Speed -- 8 16 mS Supply Current -- 8 12 mA Resolution Performance Characteristics for 5 INCH-D-DO Parameter (1) Minimum Nominal Maximum Units Overall Accuracy (5) -- 0.25 0.5 %FSO Long Term Drift (one year) -- -- 0.5 %FSO Offset Position Sensitivity (1g) -- -- 0.05 %FSO -- -- 0.25 %FSO Offset Warm-up Shift (3) Performance Characteristics for 10 INCH-D-DO and 1 PSI-D-DO Parameter (1) Minimum Nominal Maximum Units Overall Accuracy (5) -- 0.25 0.5 %FSO Long Term Drift (one year) -- -- 0.5 %FSO Offset Position Sensitivity (1g) -- -- 0.03 %FSO -- -- 0.25 %FSO Offset Warm-up Shift (3) 2-20 Performance Characteristics for 5 PSI-D-DO through 100 PSI-x-DO Parameter (1) Minimum Nominal Maximum Units Overall Accuracy (5) -- 0.10 0.25 %FSO Long Term Drift (one year) -- -- 0.25 %FSO Specification Notes NOTE 1: UNLESS OTHERWISE SPECIFIED, ALL PARAMETERS ARE MEASURED AT 5.0 VOLT SUPPLY, POSITIVE PRESSURE APPLIED TO PORT B. NOTE 2: THE DIGITAL OUTPUT IS A 16 BIT SIGNED BINARY OUTPUT IN A TWO'S COMPLIMENT FORMAT. THE APPLIED PRESSURE IS COMPUTED USING THE PRESSURE CONVERSION TABLE (BELOW). THE MODE COLUMN IDENTIFIES THE RESOLUTION OPERATING MODE OF THE DEVICE (A = STANDARD RESOLUTION, B = HIGH RESOLUTION). FSO AND UNITS ARE SHOWN FOR EACH MODEL. NOTE 3: SHIFT IS WITHIN THE FIRST HOUR OF EXCITATION APPLIED TO THE DEVICE. NOTE 4: DIGITAL SPAN IS DEPENDENT ON THE RESOLUTION OPERATING MODE. REFER TO THE DIGITAL SPAN TABLE (BELOW) TO IDENTIFY THE DIGITAL SPAN OF THE SPECIFIC MODEL. IN THE EVENT OF AN OVER-PRESSURE OR UNDER-PRESSURE CONDITION, THE DIGITAL OUTPUT WILL ONE COUNT HIGHER OR ONE COUNT LOWER (RESPECTIVELY) TO THE LISTED DIGITAL SPAN TO INDICATE THE CONDITION. NOTE 5: OVERALL ACCURACY INCLUDES THE COMBINED EFFECTS OF OFFSET AND SPAN SHIFTS OVER TEMPERATURE, LINEARITY, HYSTERESIS, AND OFFSET AND SPAN CALIBRATION. Synchronous Timing Diagram (Note: Asynchronous mode timing is per RS-232. To use RS-232 requires the Maxim MA232 interface circuit for proper voltage level compatibility.) READY [Output] t1 t10 t2 t2 CONVERT [Input] t3 t4 t8 t9 t5 CLOCK [Output] t6 t7 DATA [Output] Bit 15 MSB Ref t1 t2 t3 t4 t5 Parameter Conversion Time Ready to Convert Convert to Clock Clock Period Clock High Time Min -0 24 --- Typ 8 -32 16 8 Bit 14 Max 16 -39 --- Bit 13 Bit 12 Bit 11 Bit 10 Units msec usec usec usec usec Bit 9 Bit 8 Ref t6 t7 t8 t9 t10 Bit 7 Bit 6 Bit 5 Bit 4 Parameter Data Setup Time Data Hold Time Interbyte Delay Clock to Ready Data Transmission Bit 3 Min ------ Bit 2 Typ 3 3 57 14 335 Bit 1 Bit 0 LSB Max ------ Units usec usec usec usec usec Typical Configurations Synchronous Communications Asynchronous Communications Typical synchronous communications Typical asynchronous communications configuration (compatible with All Sensors configuration. The Mode pin is interrogated GA142 Series Digital Output Sensors). at power up and if tied low, will cause the sensor to enter asynchronous communica- Sensor Host System (1) Clock/SO Data/SI Convert/BR Ready/Mode tions mode. This mode supports multiple Host System Sensor Clock/SO Data/SI Convert/BR Ready/Mode sensors by addressable commands. The Convert/BR pin then serves to select one of two available baud rates. Sensor (n) Clock/SO Data/SI Convert/BR Ready/Mode 2-21 2 Command Summary Table: Command Description Response RA<cr> Read Accuracy String RA=[Accuracy String]<cr> RC<cr> Read Captured Pressure RC=[hhhh]<sp>[eeee]<cr> RH<cr> Read High Resolution Pressure RH=[hhhh]<sp>[eeee]<cr> RL<cr> Read Low Resolution Pressure RL[llll]<sp>[eeee]<cr> RM<cr> Read Model RM=[Model String]<cr> RR<cr> Read Pressure Range RR=[pressure Range String]<cr> RS<cr> Read Serial Number RS=[S/N String]<cr> RT<cr> Read Temperature RT=[Temperature Range String]<cr> U[S/N String][Command]<cr> Unique Command For Matching S/N U[S/N String],sp>[Response String] For Non-matching S/N {null} WC<cr> Capture Pressure {null} Notations: <> indicates a single ascii character [] indicates an ascii string {} text within the braces describes the response (this is essentially a comment) "" text within quotes represents a literal ascii text string Definitions: Term Name Description <cr> Carriage Return ascii Carrage Return. This is a command/response delimiter <sp> Space ascii Space Character [Accuracy String] Accuracy String Part accuracy string. Given in % full scale output. Example: 0.250 %FSO Notes: 1.) There is a space between the numeric accuracy "0.250" and units "%FSO." 2.) FSO stands for Full Scale Output (full scale output is determined by the Pressure Range String.) [hhhh] High Resolution Output This is a four character ascii string representing a hexidecimal value. Example: 3F7C Represents an output count of 16,252 Note: the output is forced to "8000" upon an error. except error bit 8, see error bit codes. [llll] Low Resolution Output This is a four character ascii string representing a hexidecimal value. Example: 1D58 Represents an output count of 7,512 Note: the output is forced to "8000" upon an error. except error bit 8, see error bit codes. [Model String] Model String Part Model as given in the data sheet (also order number.) The general model syntax is [Full Scale Pressure]<sp>[Pressure Units]-[Pressure Model]-DO Example: 100 PSI-D-DO Where: Full Scale Pressure=100 Pressure Units=PSI (inH2O, mbar or mmHg available) DO represents Digital Output Notes: 1.) Exception to this syntax is the Barometer. 2.) Custom models may be different. 2-22 Definitions: Term Name Description [Pressure Range String] Pressure Range String This is the compensated pressure range of the part. Syntax: [low limit]<sp>"to"<sp>[high limit]<sp>[units}[mode] Esample: 20 to 32 mmHgA Where: Low limit = 20 High limit = 32 Units = mmHg Mode = A (absolute pressure) (D differential and G gage pressure also available.) [Response String] A Fully Formed Response String Example: "RL=1E43<sp>0000<cr> [S/N String] Serial Number String YMDD-NN-BSPP (12 character String) Where: Y : Year (0~9) M : Month (A~M, excluding I) DD: Day of Month NN: Lot (lot sequence for a given day) B : Lot Batch# (A~Z) S : Test Oven Slot# (1~5) P : Position on Slot (1~15) Example: 3D23-03-A103 Month Codes January : A February : B March :C April :D May :E June :F July :G August : H September : J October : K November : L December : M April 23, 2003 3rd lot of the day Batch A, Slot 1, Position 03 This allows traceability to original test data [Temperature Range String] Temperature Range String This is the compensated temperature range of the part. Syntax: [low limit]<sp>[high limit]<sp>"C" Example: -20 to 85 C -40 to 125 C and custom ranges also available. [eeee] Error Codes The error codes are bits packed within a double byte. The four character string is an ascii hex expression. The error code bits are: Bit 0 : Part not factory compensated Bit 1 : Tdex Overflow Bit 2 : Tdex Over-range Bit 3 : Pdex Overflow Bit 4 : Pdex Over-range Bit 5 : PWL Overflow Bit 6 : Scale Overflow Bit 7 : High Resolution Overflow Bit 8 : Pressure Output Limited to Specific Value Bits 9 through 15 : Reserved Example: 0100 Represents erro bit 8 set and the Pressure Output Limited Notes: Bit 0 : This should not appear if the part has been calibrated Bits 1 thru 7 : indicate computational error when compensated Bit 8: indicates that the pressure applied to the part exceeds the range of the part and is limit to either the high or low limit {null} Null Response No response from the part. In the event of a serial number mismatch the part will not respond (to avoid buss contention.) All Sensors reserves the right to make changes to any products herein. All Sensors does 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. (R) MICROWIRE/PLUS IS A REGISTERED TRADEMARK OF NATIONAL SEMICONDUCTOR. 2-23 2