High Performance Accelerometer with
Dual Spectrum Signal Processing
Data Sheet
ADXL195/ADXL295
FEATURES
GENERAL DESCRIPTION
Single-axis (ADXL195) and dual-axis (ADXL295) configurations
120 g baseband acceleration channel
12-bit resolution at 62.5 mg/LSB
The ADXL195/ADXL295 are dual spectrum accelerometers
that measure baseband acceleration in up to two axes (XL-X
and XL-Y), as well as high frequency (HF) acceleration energy.
Identical, independent X and Y sense structures are implemented
to achieve the best possible fail-safe performance.
512 kHz data interpolation rate
40 gAVG high frequency signal processing channel
10-bit resolution at 83.3 mg avg/LSB
128 kHz data interpolation rate
Sensor frequency response down to dc
On-demand electromechanical self-test
On-demand HF signal injection self-test
Fully differential circuitry for high resistance to EMI/RFI
Independent x- and y-axis sense structures for robust
FMEA performance
The XL-X and XL-Y channels output baseband acceleration
information with a nominal full-scale range of 120 g and a
bandwidth of 408 Hz. The acceleration data is provided as a
12-bit, twos complement word with a resolution of 62.5 mg/LSB.
HF acceleration within the frequency band of 15.5 kHz to
23 kHz is rectified and filtered to generate an average g (gAVG
)
energy measurement. The HF channel has a nominal full-scale
range of 40 gAVG and a bandwidth of 393 Hz. When combined
with the XL-X and XL-Y information, HF acceleration information
allows for enhanced vehicle impact detection and discrimination.
Independent x- and y-axis arming thresholds
Low noise
1 LSB rms (12-bit baseband acceleration channel)
2 LSB rms (10-bit high frequency acceleration channel)
Qualified for automotive applications
Temperature range: −40°C to +105°C
3.3 V and 5 V operation
The ADXL195/ADXL295 are available in a 16-lead, narrow-body
SOIC package with an exposed pad. The ADXL195/ADXL295
can operate at 3.3 V and 5 V and are specified for operation from
−40°C to +105°C.
APPLICATIONS
Enhanced crash sensing
Shock detection
FUNCTIONAL BLOCK DIAGRAM
ARM_X
ARM_Y
SELF-
TEST
STATE MACHINE
HF SELF-
TEST
GND
INTERPOLATION
AT 512kHz
EPAD
OFFSET/
SENSITIVITY
CALIBRATION
3
SINC + FIR FILTER
OFFSET
CANCELLATION
–3dB AT 408Hz
Σ-Δ
MOD
AC
AMP
DEMOD
MISO
MOSI
SCLK
CS
IIR, SINC, FIR
LOW-PASS
FILTERS
BAND-PASS
FILTER
15.5kHz TO
23kHz
SENSITIVITY
CALIBRATION
INTERPOLATION
AT 128kHz
X-AXIS
SENSOR
SENSOR
DRIVERS
|ABS|
–3dB AT 393Hz
INTERPOLATION
AT 512kHz
OFFSET/
3
Σ-Δ
MOD
SINC + FIR FILTER
–3dB AT 408Hz
OFFSET
CANCELLATION
AC
AMP
SENSITIVITY
DEMOD
CALIBRATION
DEVICE ID
TRIM
VDD
OTP
MEMORY
Y-AXIS
SENSOR
SENSOR
DRIVERS
VREG
CONFIGURATION
TIMING
GENERATOR
Figure 1.
For more information about the ADXL195/ADXL295, please contact the Analog Devices, Inc., Customer Interaction Center at
http://www.analog.com/en/content/technical_support_page/fca.html to connect with a technical support specialist.
Rev. SpA
Document Feedback
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rightsof third parties that may result fromits use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks andregisteredtrademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 ©2012–2013 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com