High Performance Accelerometer with Dual Spectrum Signal Processing ADXL195/ADXL295 Data Sheet FEATURES GENERAL DESCRIPTION Single-axis (ADXL195) and dual-axis (ADXL295) configurations ±120 g baseband acceleration channel 12-bit resolution at 62.5 mg/LSB 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 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 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. 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. 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 STATE MACHINE X-AXIS SENSOR DEMOD Σ-Δ MOD BAND-PASS FILTER 15.5kHz TO 23kHz SENSOR DRIVERS OFFSET/ SENSITIVITY CALIBRATION SENSITIVITY CALIBRATION OFFSET CANCELLATION |ABS| IIR, SINC, FIR LOW-PASS FILTERS –3dB AT 393Hz MUX SINC3 + FIR FILTER –3dB AT 408Hz INTERPOLATION AT 512kHz INTERPOLATION AT 128kHz ARM_X ARM_Y GND EPAD REGISTERS/MEMORY AC AMP MUX HF SELFTEST MISO SPI INTERFACE SELFTEST ARMING PIN FUNCTIONALITY FUNCTIONAL BLOCK DIAGRAM MOSI SCLK OFFSET CANCELLATION INTERPOLATION AT 512kHz DEVICE ID Y-AXIS SENSOR OTP MEMORY SENSOR DRIVERS TRIM CONFIGURATION TIMING GENERATOR VDD VREG 10496-001 DEMOD OFFSET/ SENSITIVITY CALIBRATION VOLTAGE REGULATOR AC AMP SINC3 + FIR FILTER –3dB AT 408Hz MUX CS Σ-Δ MOD 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 rights of third parties that may result from its 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 and registered trademarks 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 ADXL195/ADXL295 Data Sheet NOTES ©2012–2013 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D10496F-0-1/13(SpA) Rev. SpA | Page 2 of 2