ADXL202E

a Low-Cost 2 g Dual-Axis Accelerometer with Duty Cycle Output ADXL202E* FUNCTIONAL BLOCK DIAGRAM 3V TO 5.25V CX VDD X SENSOR DEMOD CDC OSCILLATOR RFILT 32k ANALOG TO DUTY CYCLE (ADC) YOUT YFILT CY T2 RSET XFILT SELF-TEST FEATURES 2-Axis Acceleration Sensor on a Single IC Chip 5 mm 5 mm 2 mm Ultrasmall Chip Scale Package 2 mg Resolution at 60 Hz Low-Power < 0.6 mA Direct Interface to Low-Cost Microcontrollers via Duty Cycle Output BW Adjustment with a Single Capacitor 3 V to 5.25 V Single Supply Operation 1000 g Shock Survival APPLICATIONS 2-Axis Tilt Sensing with Faster Response than Electrolytic, Mercury, or Thermal Sensors Computer Peripherals Information Appliances Alarms and Motion Detectors Disk Drives Vehicle Security XOUT ADXL202E RFILT 32k DEMOD Y SENSOR COM C O U N T E R P T2 T1 A(g) = (T1/T2 – 0.5)/12.5% 0g = 50% DUTY CYCLE T2 = RSET/125M GENERAL DESCRIPTION The ADXL202E is a low-cost, low-power, complete 2-axis accelerometer with a digital output, all on a single monolithic IC. It is an improved version of the ADXL202AQC/JQC. The ADXL202E will measure accelerations with a full-scale range of 2 g. The ADXL202E can measure both dynamic acceleration (e.g., vibration) and static acceleration (e.g., gravity). The outputs are analog voltage or digital signals whose duty cycles (ratio of pulsewidth to period) are proportional to acceleration. The duty cycle outputs can be directly measured by a microprocessor counter, without an A/D converter or glue logic. The duty cycle period is adjustable from 0.5 ms to 10 ms via a single resistor (RSET). The typical noise floor is 200 g√Hz, allowing signals below 2 mg (at 60 Hz bandwidth) to be resolved. The bandwidth of the accelerometer is set with capacitors CX and CY at the XFILT and YFILT pins. An analog output can be reconstructed by filtering the duty cycle output. The ADXL202E is available in 5 mm hermetic LCC package. 5 mm 2 mm 8-lead *Patents Pending R EV. A 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 which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 2000 (T = T to = 25 for J Grade only, ADXL202E–SPECIFICATIONS AccelerationT= 0, gT, unlessCotherwise noted.)V A MIN MAX A DD = 5 V, RSET = 125 k , Parameter SENSOR INPUT Measurement Range2 Nonlinearity Alignment Error3 Alignment Error Cross-Axis Sensitivity4 SENSITIVITY Duty Cycle per g Duty Cycle per g Sensitivity XFILT, YFILT Sensitivity XFILT, YFILT Temperature Drift5 ZERO g BIAS LEVEL 0 g Duty Cycle 0 g Duty Cycle 0 g Voltage XFILT, YFILT 0 g Voltage XFILT, YFILT 0 g Duty Cycle vs. Supply 0 g Offset vs. Temperature5 NOISE PERFORMANCE Noise Density FREQUENCY RESPONSE 3 dB Bandwidth Sensor Resonant Frequency FILTER RFILT Tolerance Minimum Capacitance SELF-TEST Duty Cycle Change DUTY CYCLE OUTPUT STAGE FSET Output High Voltage Output Low Voltage T2 Drift vs. Temperature Rise/Fall Time POWER SUPPLY Operating Voltage Range Quiescent Supply Current Turn-On Time TEMPERATURE RANGE Specified Performance AE Operating Range Conditions Each Axis TPC1 Graph Min ±2 ADXL202JE Typ Max Min ±2 ADXL202AE Typ Max Unit g % of FS Degrees Degrees % Best Fit Straight Line X X Sensor to Y Sensor X Each Axis T1/T2, VDD = 5 V T1/T2, VDD = 3 V VDD = 5 V VDD = 3 V Delta from 25 C Each Axis T1/T2, VDD = 5 V T1/T2, VDD = 3 V VDD = 5 V VDD = 3 V Delta from 25 C @ 25 C At Pins XFILT, YFILT X X X X X X X X X X X X 10.5 9.0 265 140 0.2 ±1 0.01 ±2 12.5 11 312 167 ± 0.5 50 50 2.5 1.5 1.0 2.0 200 6 10 ± 15 1000 10 0.7 VS – 200 mV 50 200 3 5.25 1.0 3.0 160 –40 –40 1.3 200 0.7 VS – 200 mV 1000 14.5 13.0 360 195 10 8.5 250 140 0.2 ±1 0.01 ±2 12.5 11 312 167 ± 0.5 50 50 2.5 1.5 1.0 2.0 200 6 10 ± 15 15 13.5 375 200 %/g %/g mV/ g mV/ g % % % V V %/V mg / C µg√Hz rms kHz kHz % pF % 34 31 2.1 1.2 66 69 2.9 1.8 4.0 30 31 2.0 1.2 70 69 3.0 1.8 4.0 1000 32 kΩ Nominal At Pins XFILT, YFILT Self-Test “0” to “1” RSET = 125 kΩ I = 25 µA I = 25 µA 10 1.3 200 50 200 5.25 0.6 1.0 CFILT + 0.3 +85 +85 kHz V mV ppm/ C ns V mA ms C C CFILT in µF 160 0.6 CFILT + 0.3 0 70 NOTES 1 Typical Performance Characteristics. 2 Guaranteed by measurement of initial offset and sensitivity. 3 Alignment error is specified as the angle between the true and indicated axis of sensitivity (see TPC 15). 4 Cross-axis sensitivity is the algebraic sum of the alignment and the inherent sensitivity errors. 5 Defined as the output change from ambient to maximum temperature or ambient to minimum temperature. Specifications subject to change without notice. –2– REV. A ADXL202E ABSOLUTE MAXIMUM RATINGS * PIN CONFIGURATION VDD 8 Acceleration (Any Axis, Unpowered for 0.5 ms) . . . . . . 1000 g Acceleration (Any Axis, Powered for 0.5 ms) . . . . . . . . . . 500 g +VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6.0 V Output Short Circuit Duration, (Any Pin to Common) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indefinite Operating Temperature . . . . . . . . . . . . . . . . –55 C to +125 C Storage Temperature . . . . . . . . . . . . . . . . . . –65 C to +150 C *Stresses above those listed under Absolute Maximum Ratings may cause per manent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicate in the opera tional sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. XFILT YFILT XOUT 7 6 5 4 1 2 3 ST T2 COM YOUT BOTTOM VIEW PIN FUNCTION DESCRIPTIONS Drops onto hard surfaces can cause shocks of greater than 1000 g and exceed the absolute maximum rating of the device. Care should be exercised in handling to avoid damage. Package Characteristics Pin No. 1 2 3 4 5 6 7 8 Mnemonic ST T2 COM YOUT XOUT YFILT XFILT VDD Description Self-Test Connect RSET to Set T2 Period Common Y-Channel Duty Cycle Output X-Channel Duty Cycle Output Y-Channel Filter Pin X-Channel Filter Pin 3 V to 5.25 V Package Weight 8-Lead LCC JA JC Device