Rev. 18 Jan 2005 VTI Technologies reserves the right to modify this specifi cation without prior to notice.
Vout(@Vx) x
R
E = 100% xVout(@5V)
5.00V
Vx
1-
SCA1000 and SCA1020 Series
Accelerometer
FEATURES
• 2-axis measurement: SCA1000 for X - Y measurement and
SCA1020 for Z - Y measurement
• Available range ±1.7 g
• Interchangeable with SCA610/SCA620 (see interchangeability
drawing below)
• Over damped sensing element to control frequency response
• SMD DIL-12 lead-free component
• Compatible with lead-free refl ow soldering process
• Advanced internal and external connection failure detection
• Digitally activated electrostatic self-test
• Continuous memory parity check
• Single +5 V supply; two ratiometric analog voltage outputs
• Serial Peripheral Interface (SPI) compatible digital output (11 bits)
• Internal temperature sensor, accessible via SPI
BENEFITS
• Excellent reliability and stability over time and
temperature
• High resolution and low noise
• Wide operating temperature range
• Outstanding overload and shock durability
APPLICATIONS
• 2-axis acceleration measurements
• 2-axis platform leveling
• Inclination based position measurement
• 360 ° vertical orientation measurement
Note 1 100 nF supply by-pass capacitor is needed.
Note 2 Measuring directions in parallel to mounting plane, arrows showing positive acceleration
direction.
Note 3 Zero point specifi ed as Voffset = Vout(0 g) [ V ]. See note 12.
Note 4 Sensitivity specifi ed as Vsens = {Vout(+1 g) - Vout(-1 g)}/2 [ V/g ]. See note 12.
Note 5 Zero point error specifi ed as Zero point error = {Vout(0 g) – Vdd/2} / Vsens [ g ] VSens =
Nominal sensitivity Vdd/2 = Nominal offset.
Note 6 Sensitivity error specifi ed as Sensitivity error = { [Vout(+1 g)-Vout(-1 g)] / 2 - Vsens_nom} /
Vsens_nom x 100 % [% ] Vsens_nom = nominal sensitivity See note 12.
Note 7 From straight line through +1 g and -1 g points.
Note 8 The output has true DC (0 Hz) response.
Note 9 The ratiometric error is specifi ed as:
Note 10 The cross-axis sensitivity determines how much acceleration, perpendicular to the measuring
axis, couples to the output. The total crossaxis sensitivity is the geometric sum of the
sensitivities of the two axis which are perpendicular to the measuring axis. The angular
alignment error between channels 1 and 2 is included into the cross axis error.
Note 11 Typical fi gure. In addition, supply voltage noise couples to the output due to the
ratiometric nature of the accelerometer.
Note 12 Measuring directions.
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 @ 500 kHz 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
Measuring range (2 Nominal ±1.7 ±1.7 g
Measuring direction relative to
mounting plane (12 See note 12. “X”= parellel
“Y” =parallel
“Z”= perpendicular
“Y”= parallel
Zero point (3,12 Mounting position Vdd/2 Vdd/2 V
Sensitivity (4,12 @ room temperature 1.2 1.2 V/g
Zero point error over temperature (5 -25…85 °C typical ±70 ±70 mg
-40…125 °C ±100 ±100 mg
Sensitivity error over temperature (6 -25…85 °C typical ±3±3%
-40…125 °C ±4±4%
Typical non-linearity (7 Over measuring range ±20 ±20 mg
Cross-axis sensitivity (10 @ room temperature 3.5 3.5 %
Frequency response –3dB (8 @ -40…125 °C 50±30 Hz 50±30 Hz Hz
Ratiometric error (9 Vdd = 4.75...5.25 V 2 2 %
Output noise density (11 From DC...100 Hz 80 80 µg/ Hz
Digital output resolution FS 11 11 Bits
VDD = 5.00V, UNLESS OTHERWISE SPECIFIED
Preliminary
DIMENSIONS PCB PAD LAYOUTS
The accelerometer weighs < 1.2 g.
The size of the part is approximately (w x h x l) 9 x 5 x 16 mm. Pin pitch is standard 100 mils.
Acceleration in the direction of the arrow
will increase the output voltage.
SCA1000 and SCA1020 Series
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+0.3 V) V
Storage temperature range -55…125 °C
MEASURING DIRECTIONS
X: +1 g Position
Y: 0 g Position
X: 0 g Position
Y: 0 g Position
X: 0 g Position
Y: +1 g Position
X: 0 g Position
Y: 0 g Position
X: -1 g Position
Y: 0 g Position
X: 0 g Position
Y: -1 g Position
Z: +1 g Position
Y: 0 g Position
Z: 0 g Position
Y: 0 g Position
Z: 0 g Position
Y: +1 g Position
Z: 0 g Position
Y: 0 g Position
Z: -1 g Position
Y: 0 g Position
Z: 0 g Position
Y: -1 g Position
SCA1000 ( X - Y Confi guration) SCA1020 ( Z - Y Confi guration)
SENSING DIRECTION
PART NUMBER
SERIAL NUMBER
VTI Technologies Oy
Myllynkivenkuja 6
P.O. Box 27
FI-01621 Vantaa
Finland
Tel. +358 9 879 181
Fax +358 9 879 18791
sales@vti.fi
VTI Technologies Oy
Frankfurt Branch
Rennbahnstr. 72-74
D-60528 Frankfurt am Main
Germany
Tel. +49 69 6786 880
Fax +49 69 6786 8829
sales.de@vti.fi
VTI Technologies, Inc.
One Park Lane Blvd.
Suite 804 - East Tower
Dearborn, MI 48126
USA
Tel. +1 313 425 0850
Fax +1 313 425 0860
sales@vtitechnologies.com
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 fl oating or connected to GND.
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.
INTERCHANGEABILITY WITH SCA610 / SCA620
SCA1000 and SCA1020 Series
