±300 /sec Yaw Rate Gyro ADXRS620

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Rolf Lyons
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1 ±3 /sec Yaw Rate Gyro ADXRS62 FEATURES Complete rate gyroscope on a single chip Z-axis (yaw rate) response High vibration rejection over wide frequency 2 g powered shock survivability Ratiometric to referenced supply V single-supply operation 1 C operation Self-test on digital command Ultrasmall and light (<.1 cc, <. gram) Temperature sensor output RoHS compliant APPLICATIONS Vehicle chassis rollover sensing Inertial measurement units Platform stabilization GENERAL DESCRIPTION The ADXRS62 is a complete angular rate sensor (gyroscope) that uses the Analog Devices, Inc., surface-micromachining process to create a functionally complete and low cost angular rate sensor integrated with all required electronics on one chip. The manufacturing technique for this device is the same high volume BiMOS process that is used for high reliability automotive airbag accelerometers. The output signal, RATEOUT (1B, 2A), is a voltage that is proportional to angular rate about the axis normal to the top surface of the package. The output is ratiometric with respect to a provided reference supply. An external capacitor sets the bandwidth. Other external capacitors are required for operation. A temperature output is provided for compensation techniques. Two digital self-test inputs electromechanically excite the sensor to test proper operation of both the sensor and the signal conditioning circuits. The ADXRS62 is available in a 7 mm 7 mm 3 mm BGA ceramic package. FUNCTIONAL BLOCK DIAGRAM +V (ADC REF) 1nF +V AV CC ST2 ST1 TEMP V RATIO ADXRS62 1nF AGND SELF-TEST 2 C 2kΩ DEMOD DRIVE AMP MECHANICAL SENSOR AC AMP VGA 1nF +V V DD PGND CHARGE PUMP AND VOLTAGE REGULATOR 18kΩ ±1% CP1 CP2 CP3 CP4 CP SUMJ RATEOUT 22nF 22nF 1nF C OUT Figure 1. Rev. Information furnished by Analog Devices is belie ved 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. Sp ecifications subject to change without notice. No license is granted by implication or otherwise unde r any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the prop erty of their respective owners. One Technology Way, P.O. Box 916, Norwood, MA , U.S.A. Tel: Fax: Analog Devices, Inc. All rights reserved.

2 ADXRS62 TABLE OF CONTENTS Features... 1 Applications... 1 General Description... 1 Functional Block Diagram... 1 Revision History... 2 Specifications... 3 Absolute Maximum Ratings... 4 Rate Sensitive Axis... 4 ESD Caution... 4 Pin Configuration and Function Descriptions... Theory of Operation...9 Setting Bandwidth...9 Temperature Output and Calibration...9 Calibrated Performance...9 ADXRS62 and Supply Ratiometricity... 1 Null Adjustment... 1 Self-Test Function... 1 Continuous Self-Test... 1 Outline Dimensions Ordering Guide Typical Performance Characteristics... 6 REVISION HISTORY 3/1 Revision : Initial Version Rev. Page 2 of 12

3 SPECIFICATIONS ADXRS62 All minimum and maximum specifications are guaranteed. Typical specifications are not guaranteed. TA = 4 C to +1 C, VS = AVCC = VDD = V, VRATIO = AVCC, angular rate = /sec, bandwidth = 8 Hz (COUT =.1 μf), IOUT = 1 μa, ±1 g, unless otherwise noted. Table 1. Parameter Conditions Min Typ Max Unit SENSITIVITY 1 Clockwise rotation is positive output Measurement Range 2 Full-scale range over specifications range ±3 /sec Initial and Over Temperature 4 C to +1 C mv/ /sec Temperature Drift 3 ±2 % Nonlinearity Best fit straight line.1 % of FS NULL 1 Null 4 C to +1 C V Linear Acceleration Effect Any axis.1 /sec/g NOISE PERFORMANCE Rate Noise Density TA 2 C. /sec/ Hz FREQUENCY RESPONSE Bandwidth Hz Sensor Resonant Frequency khz SELF-TEST 1 ST1 RATEOUT Response ST1 pin from Logic to Logic mv ST2 RATEOUT Response ST2 pin from Logic to Logic mv ST1 to ST2 Mismatch + % Logic 1 Input Voltage 3.3 V Logic Input Voltage 1.7 V Input Impedance To common 4 1 kω TEMPERATURE SENSOR 1 VOUT at 2 C Load = 1 MΩ V Scale Factor 2 C, VRATIO = V 9 mv/ C Load to VS 2 kω Load to Common 2 kω TURN-ON TIME Power on to ±½ /sec of final ms OUTPUT DRIVE CAPABILITY Current Drive For rated specifications 2 μa Capacitive Load Drive 1 pf POWER SUPPLY Operating Voltage (VS) V Quiescent Supply Current ma TEMPERATURE RANGE Specified Performance 4 +1 C 1 Parameter is linearly ratiometric with VRATIO. 2 The maximum range possible, including output swing range, initial offset, sensitivity, offset drift, and sensitivity drift at V supplies. 3 From +2 C to 4 C or from +2 C to 1 C. 4 Adjusted by external capacitor, COUT. Reducing bandwidth below.1 Hz does not reduce noise further. Self-test mismatch is described as (ST2 + ST1)/((ST2 ST1)/2). 6 For a change in temperature from 2 C to 26 C. VTEMP is ratiometric to VRATIO. See the Tem perature Output and Calibration section for more details. Rev. Page 3 of 12

4 ADXRS62 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter Acceleration (Any Axis,. ms) Unpowered Powered VDD, AVCC VRATIO ST1, ST2 Output Short-Circuit Duration (Any Pin to Common) Operating Temperature Range Storage Temperature Range Rating 2 g 2 g.3 V to +6. V AVCC AVCC Indefinite C to +12 C 6 C to +1 C Stresses above those listed under the Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RATE SENSITIVE AXIS The ADXRS62 is a Z-axis rate-sensing device (also called a yaw rate sensing device). It produces a positive going output voltage for clockwise rotation about the axis normal to the package top, that is, clockwise when looking down at the package lid. LONGITUDINAL AXIS A1 RATE AXIS LATERAL AXIS + ABCDEFG 1 7 V CC = V GND V RATIO /2 RATE OUT 4.7V RATE IN Figure 2. RATEOUT Signal Increases with Clockwise Rotation ESD CAUTION.2V Drops onto hard surfaces can cause shocks of greater than 2 g and can exceed the absolute maximum rating of the device. Exercise care during handling to avoid damage. Rev. Page 4 of 12

5 ADXRS62 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS PGND V DD CP CP3 CP4 7 6 ST1 CP1 ST2 CP2 4 TEMP AV CC AGND V RATIO NC SUMJ G F E D C B A Figure 3. Pin Configuration RATEOUT Table 3. Pin Function Descriptions Pin No. Mnemonic Description 6D, 7D CP HV Filter Capacitor (.1 μf). 6A, 7B CP4 Charge Pump Capacitor (22 nf). 6C, 7C CP3 Charge Pump Capacitor (22 nf). A, B CP1 Charge Pump Capacitor (22 nf). 4A, 4B CP2 Charge Pump Capacitor (22 nf). 3A, 3B AVCC Positive Analog Supply. 1B, 2A RATEOUT Rate Signal Output. 1C, 2C SUMJ Output Amp Summing Junction. 1D, 2D NC No Connect. 1E, 2E VRATIO Reference Supply for Ratiometric Output. 1F, 2G AGND Analog Supply Return. 3F, 3G TEMP Temperature Voltage Output. 4F, 4G ST2 Self-Test for Sensor 2. F, G ST1 Self-Test for Sensor 1. 6G, 7F PGND Charge Pump Supply Return. 6E, 7E VDD Positive Charge Pump Supply. Rev. Page of 12

6 ADXRS62 TYPICAL PERFORMANCE CHARACTERISTICS N > 1 for all typical performance plots, unless otherwise noted RATE OUT (V) Figure 4. Null Output at 2 C (VRATIO = V) DRIFT (%) Figure 7. Sensitivity Drift over Temperature ( /sec /C) Figure. Null Drift over Temperature (VRATIO = V) ST1 Δ (mv) Figure 8. ST1 Output Change at 2 C (VRATIO = V) % OF POPULATION SENSITIVITY (mv/ /sec) Figure 6. Sensitivity at 2 C (VRATIO = V) ST2 Δ (mv) Figure 9. ST2 Output Change at 2 C (VRATIO = V) Rev. Page 6 of 12

7 ADXRS SELF-TEST MISMATCH (%) Figure 1. Self-Test Mismatch at 2 C (VRATIO = V) VOLTAGE (V) Figure 13. VTEMP Output at 2 C (VRATIO = V) ST SELF-TEST Δ (mv) 2 2 VOLTAGE (V) ST TEMPERATURE ( C) Figure 11. Typical Self-Test Change over Temperature PARTS TEMPERATURE ( C) Figure 14. VTEMP Output over Temperature (VRATIO = V) g OR /sec REF Y X CURRENT CONSUMPTION (m A) Figure 12. Current Consumption at 2 C (VRATIO = V) TIME (ms) Figure 1. g and g g Sensitivity for a g, 1 ms Pulse Rev. Page 7 of 12

8 ADXRS62 PEAK RATEOUT ( /s) LAT LONG RATE RATE OF ROTATION ( /sec) k 1k FREQUENCY (Hz) Figure 16. Typical Response to 1 g Sinusoidal Vibration (Sensor Bandwidth = 2 khz) TIME (Hours) Figure 19. Typical Shift in 9 sec Null Averages Accumulated over 14 Hours RATE OF ROTATION ( /sec) DUT1 OFFSET BY +2 /sec DUT2 OFFSET BY 2 /sec RATE OF ROTATION ( /sec) TIME (ms) Figure 17. Typical High g (2 g) Shock Response (Sensor Bandwidth = 4 Hz) TIME (Seconds) Figure 2. Typical Shift in Short-Term Null (Bandwidth = 1 Hz) ROOT ALLAN DEVIATION ( /sec rms).1.1 NOISE SPECTRAL DENSITY( /sec/ Hz rms) k 1k 1k AVERAGE TIME (Seconds) Figure 18. Typical Root Allan Deviation at 2 C vs. Averaging Time k 1k 1k FREQUENCY (Hz) Figure 21. Typical Noise Spectral Density (Bandwidth = 4 Hz) Rev. Page 8 of 12

FUNCTIONAL BLOCK DIAGRAM ST2 ST1 TEMP V RATIO 25 C MECHANICAL SENSOR AC AMP CHARGE PUMP AND VOLTAGE REGULATOR

FUNCTIONAL BLOCK DIAGRAM ST2 ST1 TEMP V RATIO 25 C MECHANICAL SENSOR AC AMP CHARGE PUMP AND VOLTAGE REGULATOR ± /s Yaw Rate Gyro ADXRS614 FEATURES Complete rate gyroscope on a single chip Z-axis (yaw rate) response High vibration rejection over wide frequency 2 g powered shock survivability Ratiometric to referenced