Datasheet ADXL195, ADXL295 (Analog Devices)

High Performance Accelerometer with Dual Spectrum Signal Processing Data Sheet ADXL195/ ADXL295 FEATURES GENERAL DESCRIPTION Single-axis (ADXL195) and dual-axis (ADXL295) c onfigurations
The ADXL195/ADXL295 are dual spectrum accelerometers
±120 g baseband acceleration channel
that measure baseband acceleration in up to two axes (XL-X
12-bit resolution at 62.5 mg /LSB
and XL-Y), as well as high frequency (HF) acceleration energy.
512 kHz data interpolation rate
Identical, independent X and Y sense structures are implemented
40 g AVG high frequency signal processing channel
to achieve the best possible fail-safe performance.
10-bit resolution at 83.3 mg avg/LSB
The XL-X and XL-Y channels output baseband acceleration
128 kHz data interpolation rate
information with a nominal ful -scale range of ±120 g and a
Sensor frequency response down to dc
bandwidth of 408 Hz. The acceleration data is provided as a
On-demand electromechanical self-test
12-bit, twos complement word with a resolution of 62.5 mg/LSB.
On-demand HF signal injection self-test Fully differential circuitry for high resistance to EMI/RFI
HF acceleration within the frequency band of 15.5 kHz to
Independent x- and y-axis sense structures for robust
23 kHz is rectified and filtered to generate an average g (gAVG)
FMEA performance
energy measurement. The HF channel has a nominal ful -scale
Independent x- and y-axis arming thresholds
range of 40 gAVG and a bandwidth of 393 Hz. When combined
Low noise
with the XL-X and XL-Y information, HF acceleration information
1 LSB rms (12-bit baseband acceleration channel)
al ows for enhanced vehicle impact detection and discrimination.
2 LSB rms (10-bit high frequency acceleration channel)
The ADXL195/ADXL295 are available in a 16-lead, narrow-body
Qualified for automotive applications
SOIC package with an exposed pad. The ADXL195/ADXL295
Temperature range: −40°C to +105°C
can operate at 3.3 V and 5 V and are specified for operation from
3.3 V and 5 V operation
−40°C to +105°C.
APPLICATIONS Enhanced crash sensing Shock detection FUNCTIONAL BLOCK DIAGRAM Y SELF- ARM_X IN IT TEST STATE MACHINE P L ARM_Y G NA IN IO M T HF SELF- TEST AR UNC F GND EPAD UX INTERPOLATION X OFFSET/ M AT 512kHz U SINC3 + FIR FILTER SENSITIVITY OFFSET Σ-Δ M –3dB AT 408Hz CANCELLATION AC CALIBRATION DEMOD MOD AMP Y MISO R O E M AC BAND-PASS IIR, SINC, FIR E F MOSI X-AXIS SENSITIVITY LOW-PASS /M R SENSOR FILTER INTERPOLATION S E SENSOR CALIBRATION |ABS| FILTERS T DRIVERS 15.5kHz TO AT 128kHz R 23kHz N –3dB AT 393Hz E T I I S SCLK GI SP E R CS UX INTERPOLATION Σ-Δ OFFSET/ M AT 512kHz AC SINC3 + FIR FILTER OFFSET DEMOD SENSITIVITY MOD AMP –3dB AT 408Hz CANCELLATION CALIBRATION DEVICE ID R E O VDD OTP G Y-AXIS TRIM A AT SENSOR MEMORY SENSOR LT UL VREG DRIVERS CONFIGURATION O G TIMING V E R
1
GENERATOR
-00 10496 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.
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Document Outline Features Applications General Description Functional Block Diagram