Preliminary SCA1000 and SCA1020 Series Accelerometer FEATURES BENEFITS • 2-axis measurement: SCA1000 for X - Y measurement and • Excellent reliability and stability over time and SCA1020 for Z - Y measurement temperature • Available range ±1.7g • High resolution and low noise • Interchangeable with SCA610/SCA620 (see interchangeability • Wide operating temperature range note below) • Outstanding overload and shock durability • Over damped sensing element to control frequency response • SMD DIL-12 lead-free component APPLICATIONS • Compatible with lead-free reflow soldering process • 2-axis acceleration measurements • Advanced internal and external connection failure detection • 2-axis platform leveling • Digitally activated electrostatic self-test • Inclination based position measurement • Continuous memory parity check • 360° vertical orientation measurement • Single +5V supply; two ratiometric analog voltage outputs • Serial Peripheral Interface (SPI) compatible digital output (11 bits) • Internal temperature sensor, accessible via SPI For customized product, please contact VTI Technologies ELECTRICAL CHARACTERISTICS Parameter Condition Min Typ. Max Units Supply voltage Vdd (1 4.75 5.0 5.25 V Current consumption Vdd = 5 V; No load 5 mA Analog resistive output load Vout to Vdd or Vss 10 kOhm Analog capacitive output load 20 nF Digital output load @ 500kHz 1 nF SPI clock frequency 500 kHz AD conversion time 150 µs Data transfer time @500 kHz clock 38 µs PERFORMANCE CHARACTERISTICS Parameter Condition SCA1000-D01 SCA1020-D02 Units (2 Measuring range Nominal ±1.7 ±1.7 g Measuring direction relative to “X”= parellel “Z”= perpendicular See note 12. (12 mounting plane “Y” =parallel “Y”= parallel (3,12 Zero point Mounting position Vdd/2 Vdd/2 V (4,12 Sensitivity @ room temperature 1.2 1.2 V/g (5 Zero point error over temperature -25…85°C typical ±70 ±70 mg -40…125°C ±100 ±100 mg (6 Sensitivity error over temperature -25…85°C typical ±3 ±3 % -40…125°C ±4 ±4 % (7 Typical non-linearity Over measuring range ±20 ±20 mg (10 Cross-axis sensitivity @ room temperature 3.5 3.5 % (8 Frequency response –3dB @ -40…125°C 50±30Hz 50±30Hz Hz (9 Ratiometric error Vdd = 4.75...5.25V 2 2 % (11 Output noise density From DC...100Hz 80 80 µg/ Hz Digital output resolution FS 11 11 Bits VDD = 5.00V, UNLESS OTHERWISE SPECIFIED Note 1. 100nF supply by-pass capacitor is needed. 5.00V Vout(@Vx) x Note 2. Measuring directions in parallel to mounting plane, arrows showing positive acceleration Vx Note 9. The ratiometric error is specified as: RE = 100% x 1- direction. Vout(@5V) Note 3. Zero point specified as Voffset = Vout(0g) [ V ]. See note 12. Note 4. Sensitivity specified as Vsens = {Vout(+1g) - Vout(-1g)}/2 [ V/g ]. See note 12. Note 5. Zero point error specified as Zero point error = {Vout(0g) – Vdd/2} / Vsens [ g ] VSens = Note 10. The cross-axis sensitivity determines how much acceleration, perpendicular to the measuring Nominal sensitivity Vdd/2 = Nominal offset. axis, couples to the output. The total crossaxis sensitivity is the geometric sum of the sensi- Note 6. Sensitivity error specified as Sensitivity error = { [Vout(+1g)-Vout(-1g)] / 2 - Vsens_nom} / tivities of the two axis which are perpendicular to the measuring axis. The angular alignment Vsens_nom x 100% [% ] Vsens_nom = nominal sensitivity See note 12. error between channels 1 and 2 is included into the cross axis error. Note 7. From straight line through +1g and -1g points. Note 11. Typical figure. In addition, supply voltage noise couples to the output due to the Note 8 The output has true DC (0Hz) response. ratiometric nature of the accelerometer. Note 12. Measuring directions. Rev. 4 Jan 2005 VTI Technologies reserves the right to modify this specification without prior to notice. SCA1000 and SCA1020 Series MEASURING DIRECTIONS SCA1000 ( X - Y Configuration) SCA1020 ( Z - Y Configuration) X: +1g Position X: 0g Position X: -1g Position Z: +1g Position Z: 0g Position Z: -1g Position Y: 0g Position Y: 0g Position Y: 0g Position Y: 0g Position Y: 0g Position Y: 0g Position X: 0g Position X: 0g Position X: 0g Position Z: 0g Position Z: 0g Position Z: 0g Position Y: +1g Position Y: 0g Position Y: -1g Position Y: +1g Position Y: 0g Position Y: -1g Position ABSOLUTE MAXIMUM RATINGS Parameter Value Unit Acceleration (powered or non powered) 20 000 g Supply voltage -0.3 V to +5.5 V V Voltage at input/output pins -0.3 V to (Vdd+0.3V) V Storage temperature range -55…125 °C DIMENSIONS PCB PAD LAYOUTS The accelerometer weighs < 1.2g. The size of the part is approximately (w x h x l) 9 x 5 x 16 mm. Pin pitch is standard 100 mils. SENSING DIRECTION PART NUMBER SERIAL NUMBER Acceleration in the direction of the arrow will increase the output voltage. SCA1000 and SCA1020 Series ELECTRICAL CONNECTION RECOMMENDED CIRCUIT Pin# Pin Name I/O Connection 1 SCK Input Serial clock 2 NC Factory only 3 MISO Output Master in slave out; data output 4 MOSI Input Master out slave in; data input 5 Out_2 Output Channel 2 Output (Y-axis) 6 VSS Power Negative supply voltage (VSS) 7 CSB Input Chip select (active low) 8 NC Factory only 9 ST_2 Input Self test input for Channel 2 10 ST_1 Input Self test input for Channel 1 11 Out_1 Output Channel 1 output (X or Z-axis) 12 VDD Power Positive supply voltage (VDD) Self test can be activated applying logic “1” (positive supply voltage level) to ST pin (pin 9 and 10). If ST feature is not used pins 9 and 10 must be left floating or connected to GND. INTERCHANGEABILITY WITH SCA610 / SCA620 When SCA1000 / 1020 is used in Analog mode and the PCB is designed correctly the SCA610 / 620 and SCA1000 / 1020 are interchangeable. If the PCB layout is designed for SCA1000 /1020, then SCA610 / 620 can be used for single axis applications. The output of SCA610 / 620 corresponds to the output of channel 1 in the SCA1000 / 1020. VTI Technologies Oy VTI Technologies Oy VTI Technologies, Inc. Myllynkivenkuja 6 Frankfurt Branch One Park Lane Blvd. P.O. Box 27 Rennbahnstr. 72-74 Suite 804 - East Tower FI-01621 Vantaa D-60528 Frankfurt am Main Dearborn, MI 48126 Finland Germany USA Tel. +358 9 879181 Tel. +49 69 6786 880 Tel. +1 313 425 0850 Fax +358 9 87918791 Fax +49 69 6786 8829 Fax +1 313 425 0860 sales@vti.fi sales.de@vti.fi sales@vtitechnologies.com