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SCA100T,高精度两轴加速度计

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Data Sheet SCA100T Series THE SCA100T DUAL AXIS INCLINOMETER SERIES The SCA100T Series is a 3D-MEMS-based dual axis inclinometer family that provides instrumentation grade performance for leveling applications. The measuring axes of the sensing elements are parallel to the mounting plane and orthogonal to each other. Low temperature dependency, high resolution and low noise, together a with robust sensing element design, make the SCA100T the ideal choice for leveling instruments. The VTI inclinometers are insensitive to vibration, due to their over damped sensing elements, and can withstand mechanical shocks of up to 20000 g. Features x Dual axis inclination measurement (X and Y) x Measuring ranges ±30° SCA100T-D01 and ± 90° SCA100T-D02 x 0.0025° resolution (10 Hz BW, analog output) x Sensing element controlled over damped frequency response (-3dB 18Hz) x Robust design, high shock durability (20000g) x High stability over temperature and time x Single +5 V supply x Ratiometric analog voltage outputs x Digital SPI inclination and temperature output x Comprehensive failure detection features o True self test by deflecting the sensing elements’ proof mass by electrostatic force. o Continuous sensing element interconnection failure check. o Continuous memory parity check. x RoHS compliant x Compatible with Pb-free reflow solder process Applications x Platform leveling and stabilization x 360° vertical orientation measurement x Leveling instruments x Construction levels 12 VDD Sensing element 1 Signal conditioning and filtering 10 ST_1 9 ST_2 Self test 1 Self test 2 EEPROM calibration memory Temperature Sensor Sensing element 2 Signal conditioning and filtering A/D conversion SPI interface 11 OUT_1 1 SCK 3 MISO 4 MOSI 7 CSB 5 OUT_2 Figure 1. Functional block diagram 6 GND Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc.Nr. 8261800 Rev.A SCA100T Series TABLE OF CONTENTS The SCA100T Dual Axis Inclinometer Series .........................................................................1 Features ................................................................................................................................................ 1 Applications .........................................................................................................................................1 Table of Contents .....................................................................................................................2 1 Electrical Specifications .....................................................................................................3 1.1 Absolute Maximum Ratings......................................................................................................3 1.2 Performance Characteristics ....................................................................................................3 1.3 Electrical Characteristics ..........................................................................................................4 1.4 SPI Interface DC Characteristics ..............................................................................................4 1.5 SPI Interface AC Characteristics ..............................................................................................4 1.6 SPI Interface Timing Specifications .........................................................................................5 1.7 Electrical Connection ................................................................................................................6 1.8 Typical Performance Characteristics.......................................................................................6 1.8.1 Additional External Compensation ....................................................................................... 7 2 Functional Description .......................................................................................................9 2.1 Measuring Directions ................................................................................................................9 2.2 Voltage to Angle Conversion....................................................................................................9 2.3 Ratiometric Output ..................................................................................................................10 2.4 SPI Serial Interface ..................................................................................................................10 2.5 Digital Output to Angle Conversion .......................................................................................12 2.6 Self Test and Failure Detection Modes ..................................................................................13 2.7 Temperature Measurement .....................................................................................................14 3 Application Information ....................................................................................................15 3.1 Recommended Circuit Diagrams and Printed Circuit Board Layouts ................................15 3.2 Recommended Printed Circuit Board Footprint ...................................................................16 4 Mechanical Specifications and Reflow Soldering ..........................................................16 4.1 Mechanical Specifications (Reference only) .........................................................................16 4.2 Reflow Soldering......................................................................................................................17 5 Document Change Control...............................................................................................18 6 Contact Information ..........................................................................................................18 Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series 1 Electrical Specifications The SCA100T product family comprises two versions, the SCA100T-D01 and the SCA100T-D02 that differ in measurement range. The product version specific performance specifications are listed in the table SCA100T performance characteristics below. All other specifications are common with both versions. Vdd=5.00V and ambient temperature unless otherwise specified. 1.1 Absolute Maximum Ratings Supply voltage (VDD) Voltage at input / output pins Storage temperature Operating temperature Mechanical shock -0.3 V to +5.5V -0.3V to (VDD + 0.3V) -55°C to +125°C -40°C to +125°C Drop from 1 meter onto a concrete surface (20000g). Powered or non-powered 1.2 Performance Characteristics Parameter Condition SCA100T SCA100T -D01 -D02 Units Measuring range Nominal ±30 ±90 ° Frequency response –3dB LP (1 ±0.5 ±1.0 g 8-28 8-28 Hz Offset (Output at 0g) Ratiometric output Vdd/2 Vdd/2 V Offset calibration error ±0.11 ±0.23 ° Offset Digital Output 1024 1024 LSB Sensitivity 4 2 V/g between 0…1° (2 70 35 mV/° Sensitivity calibration error ±0.5 ±0.5 % Sensitivity Digital Output 1638 819 LSB / g Offset temperature dependency -25…85°C (typical) ±0.008 ±0.008 °/°C -40…125°C (max) ±0.86 ±0.86 ° Sensitivity temperature dependency -25...85°C (typical) -40…125°C (max) ±0.014 -2.5...+1 ±0.014 -2.5...+1 %/°C % Typical non-linearity Measuring range ±0.11 ±0.57 ° Digital output resolution 11 11 Bits between 0…1° (2 0.035 0.07 ° / LSB Output noise density Analog output resolution From DC...100Hz Bandwidth 10 Hz (3 0.0008 0.0025 0.0008 0.0025 q / Hz ° Ratiometric error Vdd = 4.75...5.25V ±1 ±1 % Cross-axis sensitivity Long term Stability (4 Max. 4 4 % <0.014 <0.014 ° Note 1. Note 2. Note 3. Note 4. The frequency response is determined by the sensing element’s internal gas damping. The angle output has SIN curve relationship to voltage output refer to paragraph Error! Reference source not found. Resolution = Noise density * ¥(bandwidth) Power continuously connected (@ 23°C). Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series 1.3 Electrical Characteristics Parameter Condition Min. Typ Max. Units Supply voltage Vdd 4.75 5.0 5.25 V Current consumption Vdd = 5 V; No load 4 5 mA Operating temperature -40 +125 °C Analog resistive Vout to Vdd or GND 10 output load kOhm Analog capacitive output load Vout to Vdd or GND 20 nF Start-up delay Reset and parity check 10 ms 1.4 SPI Interface DC Characteristics Parameter Conditions Symbol Min Typ Max Unit Input terminal CSB Pull up current Input high voltage Input low voltage Hysteresis Input capacitance VIN = 0 V IPU VIH VIL VHYST CIN 13 22 35 PA 4 Vdd+0.3 V -0.3 1 V 0.23*Vdd V 2 pF Input terminal MOSI, SCK Pull down current Input high voltage Input low voltage Hysteresis VIN = 5 V Input capacitance IPD VIH VIL VHYST CIN 9 17 29 PA 4 Vdd+0.3 V -0.3 1 V 0.23*Vdd V 2 pF Output terminal MISO Output high voltage I > -1mA Output low voltage Tristate leakage I < 1 mA 0 < VMISO < Vdd VOH VOL ILEAK Vdd0.5 5 V 0.5 V 100 pA 1.5 SPI Interface AC Characteristics Parameter Output load SPI clock frequency Internal A/D conversion time Data transfer time Condition @500kHz @500kHz Min. Typ. 150 38 Max. 1 500 Units nF kHz Ps Ps Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series 1.6 SPI Interface Timing Specifications Parameter Terminal CSB, SCK Time from CSB (10%) to SCK (90%) Time from SCK (10%) to CSB (90%) Terminal SCK SCK low time SCK high time Terminal MOSI, SCK Time from changing MOSI (10%, 90%) to SCK (90%). Data setup time Time from SCK (90%) to changing MOSI (10%,90%). Data hold time Terminal MISO, CSB Time from CSB (10%) to stable MISO (10%, 90%). Time from CSB (90%) to high impedance state of MISO. Terminal MISO, SCK Time from SCK (10%) to stable MISO (10%, 90%). Terminal CSB Time between SPI cycles, CSB at high level (90%) When using SPI commands RDAX, RDAY, RWTR: Time between SPI cycles, CSB at high level (90%) Conditions Load capacitance at MISO < 2 nF Load capacitance at MISO < 2 nF Load capacitance at MISO < 15 pF Load capacitance at MISO < 15 pF Load capacitance at MISO < 15 pF Symbol Min. Typ. Max. Unit TLS1 120 ns TLS2 120 ns TCL 1 Ps TCH 1 Ps TSET 30 ns THOL 30 ns TVAL1 10 TLZ 10 100 ns 100 ns TVAL2 100 ns TLH 15 Ps TLH 150 Ps TLS1 TCH TCL TLS2 TLH CSB SCK THOL TSET MOSI MSB in DATA in LSB in TVAL1 TVAL2 TLZ MISO MSB out DATA out LSB out Figure 2. Timing diagram for SPI communication Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series 1.7 Electrical Connection If the SPI interface is not used SCK (pin1), MISO (pin3), MOSI (pin4) and CSB (pin7) must be left floating. Self-test can be activated applying logic “1” (positive supply voltage level) to ST_1 or ST_2 pins (pins 10 or 9). Self-test must not be activated for both channels at the same time. If ST feature is not used pins 9 and 10 must be left floating or connected to GND. Inclination signals are provided from pins OUT_1 and OUT_2. SSCCKK 1 Ext_C_1 2 MMISIOSO 3 12 VVDDDD 11 OOUUTT_1_1 10 STS_T1_/1Test_in MMOOSSI I 4 OOUUTT__22 5 GNVDSS 6 9 STS_T2_2 8 Ext_C_2 7 CCSBSB Figure 3. SCA100T electrical connection No. Node 1 SCK 2 NC 3 MISO 4 MOSI 5 Out_2 6 GND 7 CSB 8 NC 9 ST_2 10 ST_1 11 Out_1 12 VDD I/O Input Input Output Input Output Supply Input Input Input Input Output Supply Description Serial clock No connect, left floating Master in slave out; data output Master out slave in; data input Y axis Output (Ch 2) Ground Chip select (active low) No connect, left floating Self test input for Ch 2 Self test input for Ch 1 X axis Output (Ch 1) Positive supply voltage (+5V DC) 1.8 Typical Performance Characteristics Typical offset and sensitivity temperature dependencies of the SCA100T are presented in following diagrams. These results represent the typical performance of SCA100T components. The mean value and 3 sigma limits (mean ± 3u standard deviation) and specification limits are presented in following diagrams. The 3 sigma limits represents 99.73% of the SCA100T population. Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series Temperature dependency of SCA100T offset offset error [degrees] 1 specification limit 0.8 0.6 0.4 0.2 Average 0 +3 sigma -0.2 -3 sigma -0.4 -0.6 -0.8 specification limit -1 -40 -20 0 20 40 60 80 100 120 Temp [°C] Figure 4. Typical temperature dependency of SCA100T offset sensitivity error [%] Temperature dependency of SCA100T sensitivity 1.00 specification limit 0.50 0.00 -0.50 -1.00 -1.50 Average +3 sigma -3 sigma -2.00 -2.50 specification limit -40 -20 0 20 40 60 80 100 120 Temp [°C] Figure 5. Typical temperature dependency of SCA100T sensitivity 1.8.1 Additional External Compensation To achieve the best possible accuracy, the temperature measurement information and typical temperature dependency curves can be used for SCA100T offset and sensitivity temperature dependency compensation. The equation of fitted 3rd order polynome curve for offset compensation is: Offcorr 0.0000006 *T 3  0.0001*T 2  0.0039 *T  0.0522 Where: Offcorr: T 3rd order polynome fitted to average offset temperature dependency curve temperature in °C (Refer to paragraph 2.7 Temperature Measurement) The calculated compensation curve can be used to compensate the temperature dependency of the SCA100T offset by using following equation: OFFSETcomp Offset  Offcorr Where: OFFSETcomp Offset temperature compensated offset in degrees Nominal offset in degrees Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series The equation of fitted 2nd order polynome curve for sensitivity compensation is: Scorr 0.00011*T 2  0.0022 *T  0.0408 Where: Scorr: T 2nd order polynome fitted to average sensitivity temperature dependency curve temperature in °C The calculated compensation curve can be used to compensate the temperature dependency of the SCA100T sensitivity by using following equation: SENScomp SENS * (1 Scorr /100) Where: SENScomp temperature compensated sensitivity SENS Nominal sensitivity (4V/g SCA100T-D01, 2V/g SCA100T-D02) The typical offset and sensitivity temperature dependency after external compensation is shown in the pictures below. offset error [degrees] Temperature dependency of externally compensated SCA100T offset 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 -40 -20 0 20 40 60 80 100 120 Temp [°C] Average +3 sigma -3 sigma Figure 6. The temperature dependency of an externally compensated SCA100T offset sensitivity error [%] Temperature dependency of externally compensated SCA100T sensitivity 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 -40 -20 0 20 40 60 80 100 120 Temp [°C] Average +3 sigma -3 sigma Figure 7. The temperature dependency of an externally compensated SCA100T sensitivity Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A 2 Functional Description 2.1 Measuring Directions X-axis SCA100T Series Y-axis VOUT > VOUT =2.5V Figure 8. The measuring directions of the SCA100T > VOUT 2.2 Voltage to Angle Conversion Analog output can be transferred to angle using the following equation for conversion: D arcsin¨¨©§ Vout  Offset Sensitivity ¸¸¹· where: Offset = output of the device at 0° inclination position, Sensitivity is the sensitivity of the device and VDout is the output of the SCA100T. The nominal offset is 2.5 V and the sensitivity is 4 V/g for the SCA100T-D01 and 2 V/g for the SCA100T-D02. Angles close to 0° inclination can be estimated quite accurately with straight line conversion but for the best possible accuracy, arcsine conversion is recommended to be used. The following table shows the angle measurement error if straight line conversion is used. Straight line conversion equation: D Vout  Offset Sensitivity Where: Sensitivity = 70mV/° with SCA100T-D01 or Sensitivity= 35mV/° with SCA100T-D02 Tilt angle [°] 0 1 2 3 4 5 10 15 30 Straight line conversion error [°] 0 0.0027 0.0058 0.0094 0.0140 0.0198 0.0787 0.2185 1.668 Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series 2.3 Ratiometric Output Ratiometric output means that the zero offset point and sensitivity of the sensor are proportional to the supply voltage. If the SCA100T supply voltage is fluctuating the SCA100T output will also vary. When the same reference voltage for both the SCA100T sensor and the measuring part (A/Dconverter) is used, the error caused by reference voltage variation is automatically compensated for. 2.4 SPI Serial Interface A Serial Peripheral Interface (SPI) system consists of one master device and one or more slave devices. The master is defined as a micro controller providing the SPI clock and the slave as any integrated circuit receiving the SPI clock from the master. The ASIC in VTI Technologies’ products always operates as a slave device in master-slave operation mode. The SPI has a 4-wire synchronous serial interface. Data communication is enabled by a low active Slave Select or Chip Select wire (CSB). Data is transmitted by a 3-wire interface consisting of wires for serial data input (MOSI), serial data output (MISO) and serial clock (SCK). MASTER MICROCONTROLLER SLAVE DATA OUT (MOSI) SI DATA IN (MISO) SO SERIAL CLOCK (SCK) SCK SS0 CS SS1 SI SS2 SO SS3 SCK CS SI SO SCK CS SI SO SCK CS Figure 9. Typical SPI connection The SPI interface in VTI products is designed to support any micro controller that uses SPI bus. Communication can be carried out by either a software or hardware based SPI. Please note that in the case of hardware based SPI, the received acceleration data is 11 bits. The data transfer uses the following 4-wire interface: MOSI MISO SCK CSB master out slave in master in slave out serial clock chip select (low active) µP ĺ SCA100TG SCA100T ĺ µPG µP ĺ SCA100TG µP ĺ SCA100T Each transmission starts with a falling edge of CSB and ends with the rising edge. During transmission, commands and data are controlled by SCK and CSB according to the following rules: x commands and data are shifted; MSB first, LSB last x each output data/status bits are shifted out on the falling edge of SCK (MISO line) Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series x each bit is sampled on the rising edge of SCK (MOSI line) x after the device is selected with the falling edge of CSB, an 8-bit command is received. The command defines the operations to be performed x the rising edge of CSB ends all data transfer and resets internal counter and command register x if an invalid command is received, no data is shifted into the chip and the MISO remains in high impedance state until the falling edge of CSB. This reinitializes the serial communication. x data transfer to MOSI continues immediately after receiving the command in all cases where data is to be written to SCA100T’s internal registers x data transfer out from MISO starts with the falling edge of SCK immediately after the last bit of the SPI command is sampled in on the rising edge of SCK x maximum SPI clock frequency is 500kHz x maximum data transfer speed for RDAX and RDAY is 5300 samples per sec / channel SPI command can be either an individual command or a combination of command and data. In the case of combined command and data, the input data follows uninterruptedly the SPI command and the output data is shifted out parallel with the input data. The SPI interface uses an 8-bit instruction (or command) register. The list of commands is given in Table below. Command name MEAS RWTR RDSR RLOAD STX STY RDAX RDAY Command format 00000000 00001000 00001010 00001011 00001110 00001111 00010000 00010001 Description: Measure mode (normal operation mode after power on) Read and write temperature data register Read status register Reload NV data to memory output register Activate Self test for X-channel Activate Self test for Y-channel Read X-channel acceleration through SPI Read Y-channel acceleration through SPI Measure mode (MEAS) is standard operation mode after power-up. During normal operation, the MEAS command is the exit command from Self test. Read temperature data register (RWTR) reads temperature data register during normal operation without affecting the operation. The temperature data register is updated every 150 µs. The load operation is disabled whenever the CSB signal is low, hence CSB must stay high at least 150 µs prior to the RWTR command in order to guarantee correct data. The data transfer is presented in Figure 10 below. The data is transferred MSB first. In normal operation, it does not matter what data is written into temperature data register during the RWTR command and hence writing all zeros is recommended. CSB SCK MOSI M ISO 01 23 45 67 8 9 10 11 12 13 14 15 COMMAND H IG H IM PED AN C E DATA IN 76 5 4 3 2 10 76 DATA OUT 5 4 3 2 10 Figure 10. Command and 8 bit temperature data transmission over the SPI Self test for X-channel (STX) activates the self test function for the X-channel (Channel 1). The internal charge pump is activated and a high voltage is applied to the X-channel acceleration Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series sensor element electrode. This causes the electrostatic force that deflects the beam of the sensing element and simulates the acceleration to the positive direction. The self-test is de-activated by giving the MEAS command. The self test function must not be activated for both channels at the same time. Self test for Y-channel (STY) activates the self test function for the Y-channel (Channel 2). The internal charge pump is activated and a high voltage is applied to the Y-channel acceleration sensor element electrode. Read X-channel acceleration (RDAX) accesses the AD converted X-channel (Channel 1) acceleration signal stored in acceleration data register X. Read Y-channel acceleration (RDAY) accesses the AD converted Y-channel (Channel 2) acceleration signal stored in acceleration data register Y. During normal operation, acceleration data registers are reloaded every 150 µs. The load operation is disabled whenever the CSB signal is low, hence CSB must stay high at least 150 µs prior the RDAX command in order to guarantee correct data. Data output is an 11-bit digital word that is fed out MSB first and LSB last. CSB SCK 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 M OSI M ISO COM M AND H IG H IM PE D A N C E DATA OUT 10 9 8 7 6 5 4 3 2 1 0 Figure 11. Command and 11 bit acceleration data transmission over the SPI 2.5 Digital Output to Angle Conversion The acceleration measurement results in RDAX and RDAY data registers are in 11 bit digital word format. The data range is from 0 to 2048. The nominal content of RDAX and RDAY data registers in zero angle position are: Binary: 100 0000 0000 Decimal: 1024 The transfer function from differential digital output to angle can be presented as D arcsin¨¨©§ Dout >LSB@ Dout@0q >LSB@ Sens >LSB/g@ ¸¸¹· where; Dout Dout@0° D digital output (RDAX or RDAY) digital offset value, nominal value = 1024 angle Sens sensitivity of the device. (SCA100T-D01: 1638, SCA100T-D02: 819) Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series As an example following table contains data register values and calculated differential digital output values with -5, -1 0, 1 and 5 degree tilt angles. Angle [°] -5 -1 0 1 5 Acceleration [mg] -87.16 -17.45 0 17.45 87.16 RDAX (SCA100TD01) dec: 881 bin: 011 0111 0001 dec: 995 bin: 011 1110 0011 dec: 1024 bin: 100 0000 0000 dec: 1053 bin: 100 0001 1101 dec: 1167 bin: 100 1000 1111 RDAX (SCA100TD02) dec: 953 bin: 011 1011 1001 dec: 1010 bin: 011 1111 0010 dec: 1024 bin: 100 0000 0000 dec: 1038 bin: 100 0000 1110 dec: 1095 bin: 100 0100 0111 2.6 Self Test and Failure Detection Modes To ensure reliable measurement results the SCA100T has continuous interconnection failure and calibration memory validity detection. A detected failure forces the output signal close to power supply ground or VDD level, outside the normal output range. The normal output ranges are: analog 0.25-4.75 V (@Vdd=5V) and SPI 102...1945 counts. The calibration memory validity is verified by continuously running parity check for the control register memory content. In the case where a parity error is detected, the control register is automatically re-loaded from the EEPROM. If a new parity error is detected after re-loading data both analog output voltages are forced to go close to ground level (<0.25 V) and SPI outputs go below 102 counts. The SCA100T also includes a separate self test mode. The true self test simulates acceleration, or deceleration, using an electrostatic force. The electrostatic force simulates acceleration that is high enough to deflect the proof mass to the extreme positive position, and this causes the output signal to go to the maximum value. The self test function is activated either by a separate on-off command on the self test input, or through the SPI. The self-test generates an electrostatic force, deflecting the sensing element’s proof mass, thus checking the complete signal path. The true self test performs following checks: x Sensing element movement check x ASIC signal path check x PCB signal path check x Micro controller A/D and signal path check The created deflection can be seen in both the SPI and analogue output.s The self test function is activated digitally by a STX or STY command, and de-activated by a MEAS command. Self test can be also activated applying logic”1” (positive supply voltage level) to ST pins (pins 9 & 10) of SCA100T. The self test Input high voltage level is 4 – Vdd+0.3 V and input low voltage level is 0.3 – 1 V. The self test function must not be activated for both channels at the same time. Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series 5V ST pin voltage 0V 5V V1 V2 V3 Vout 0V T1 T2 T3 T5 T4 Figure 12. Self test wave forms V1 = initial output voltage before the self test function is activated. V2 = output voltage during the self test function. V3 = output voltage after the self test function has been de-activated and after stabilization time Please note that the error band specified for V3 is to guarantee that the output is within 5% of the initial value after the specified stabilization time. After a longer time (max. 1 second) V1=V3. T1 = Pulse length for Self test activation T2 = Saturation delay T3 = Recovery time T4 = Stabilization time =T2+T3 T5 = Rise time during self test. Self test characteristics: T1 [ms] T2 [ms] T3 [ms] 20-100 Typ. 25 Typ. 30 T4 [ms] Typ. 55 T5 [ms] Typ. 15 V2: Min 0.95*VDD (4.75V @Vdd=5V) V3: 0.95*V1-1.05*V1 2.7 Temperature Measurement The SCA100T has an internal temperature sensor, which is used for internal offset compensation. The temperature information is also available for additional external compensation. The temperature sensor can be accessed via the SPI interface and the temperature reading is an 8-bit word (0…255). The transfer function is expressed with the following formula: T Counts  197  1.083 Where: Counts Temperature reading T Temperature in °C The temperature measurement output is not calibrated. The internal temperature compensation routine uses relative results where absolute accuracy is not needed. If the temperature measurement results are used for additional external compensation then one point calibration in the system level is needed to remove the offset. With external one point calibration the accuracy of the temperature measurement is about ±1 °C. Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series 3 Application Information 3.1 Recommended Circuit Diagrams and Printed Circuit Board Layouts The SCA100T should be powered from a well regulated 5 V DC power supply. Coupling of digital noise to the power supply line should be minimized. 100nF filtering capacitor between VDD pin 12 and GND plane must be used. The SCA100T has a ratiometric output. To get the best performance use the same reference voltage for both the SCA100T and Analog/Digital converter. Use low pass RC filters with 5.11 kȍ and 10nF on the SCA100T outputs to minimize clock noise. Locate the 100nF power supply filtering capacitor close to VDD pin 12. Use as short a trace length as possible. Connect the other end of capacitor directly to the ground plane. Connect the GND pin 6 to underlying ground plane. Use as wide ground and power supply planes as possible. Avoid narrow power supply or GND connection strips on PCB. Figure 13. Analog connection and layout example Figure 14. SPI connection example Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A 3.2 Recommended Printed Circuit Board Footprint SCA100T Series Figure 15. Recommended PCB footprint 4 Mechanical Specifications and Reflow Soldering 4.1 Mechanical Specifications (Reference only) Lead frame material: Plating: Solderability: RoHS compliance: Co-planarity error The part weights Copper Nickel followed by Gold JEDEC standard: JESD22-B102-C RoHS compliant lead free component. 0.1mm max. <1.2 g Figure 16. Mechanical dimensions of the SCA100T (Dimensions in mm) Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A SCA100T Series 4.2 Reflow Soldering The SCA100T is suitable for Sn-Pb eutectic and Pb- free soldering process and mounting with normal SMD pick-and-place equipment. Figure 17. Recommended SCA100T body temperature profile during reflow soldering. Ref. IPC/JEDEC J-STD-020B. Profile feature Average ramp-up rate (TL to TP) Preheat - Temperature min (Tsmin) - Temperature max (Tsmax) - Time (min to max) (ts) Tsmax to T, Ramp up rate Time maintained above: - Temperature (TL) - Time (tL) Peak temperature (TP) Time within 5°C of actual Peak Temperature (TP) Ramp-down rate Time 25° to Peak temperature Sn-Pb Eutectic Assembly 3°C/second max. 100°C 150°C 60-120 seconds 183°C 60-150 seconds 240 +0/-5°C 10-30 seconds 6°C/second max 6 minutes max Pb-free Assembly 3°C/second max. 150°C 200°C 60-180 seconds 3°C/second max 217°C 60-150 seconds 250 +0/-5°C 20-40 seconds 6°C/second max 8 minutes max The Moisture Sensitivity Level of the part is 3 according to the IPC/JEDEC J-STD-020B. The part should be delivered in a dry pack. The manufacturing floor time (out of bag) in the customer’s end is 168 hours. Notes: x Preheating time and temperatures according to guidance from solder paste manufacturer. x It is important that the part is parallel to the PCB plane and that there is no angular alignment error from intended measuring direction during assembly process. x Wave soldering is not recommended. x Ultrasonic cleaning is not allowed. The sensing element may be damaged by an ultrasonic cleaning process. Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A 5 Document Change Control Version Date A 1.9.-06 Change Description Initial release SCA100T Series Shanghai Lamshine Co. LTD Tel: 021-58796509 www.51sensor.com Email: sales@51sensor.com Doc. nr. 8261800 Rev.A

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