Dual-Axis 1.7 g Accelerometer with SPI Interface ADIS16003 Data Sheet FEATURES GENERAL DESCRIPTION Dual-axis accelerometer SPI digital output interface Internal temperature sensor Highly integrated; minimal external components Bandwidth externally selectable 1 mg resolution at 60 Hz Externally controlled electrostatic self-test 3.0 V to 5.25 V single-supply operation Low power: <2 mA 3500 g shock survival 7.2 mm x 7.2 mm x 3.7 mm package The ADIS16003 is a low cost, low power, complete dual-axis accelerometer with an integrated serial peripheral interface (SPI). An integrated temperature sensor is also available on the SPI interface. The ADIS16003 measures acceleration with a fullscale range of 1.7 g (minimum), and it can measure both dynamic acceleration (vibration) and static acceleration (gravity). APPLICATIONS An externally driven self-test pin (ST) allows the user to verify the accelerometer functionality. The typical noise floor is 110 g/Hz, allowing signals below 1 mg (60 Hz bandwidth) to be resolved. The bandwidth of the accelerometer is set with optional capacitors CX and CY at the XFILT and YFILT pins. Selection of the two analog input channels is controlled via the serial interface. Industrial vibration/motion sensing Platform stabilization Dual-axis tilt sensing Tracking, recording, and analysis devices Alarms and security devices The ADIS16003 is available in a 7.2 mm x 7.2 mm x 3.7 mm, 12-terminal LGA package. FUNCTIONAL BLOCK DIAGRAM VCC SCLK DUAL-AXIS 1.7g ACCELEROMETER SERIAL INTERFACE DIN DOUT CS CDC TCS COM ST YFILT XFILT CY CX 056463-001 TEMP SENSOR Figure 1. Rev. B 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 www.analog.com Fax: 781.461.3113 (c)2005-2012 Analog Devices, Inc. All rights reserved. ADIS16003 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Self-Test ....................................................................................... 11 Applications....................................................................................... 1 Serial Interface ............................................................................ 11 General Description ......................................................................... 1 Accelerometer Serial Interface.................................................. 11 Functional Block Diagram .............................................................. 1 Temperature Sensor Serial Interface........................................ 12 Revision History ............................................................................... 2 Power Supply Decoupling ......................................................... 12 Specifications..................................................................................... 3 Setting the Bandwidth ............................................................... 13 Timing Specifications .................................................................. 4 Circuit and Timing Diagrams..................................................... 5 Selecting Filter Characteristics: The Noise/Bandwidth TradeOff................................................................................................. 13 Absolute Maximum Ratings............................................................ 6 Applications Information .............................................................. 15 ESD Caution.................................................................................. 6 Dual-Axis Tilt Sensor ................................................................ 15 Pin Configuration and Function Descriptions............................. 7 Second Level Assembly ............................................................. 15 Typical Performance Characteristics ............................................. 8 Outline Dimensions ....................................................................... 16 Theory of Operation ...................................................................... 11 Ordering Guide .......................................................................... 16 Accelerometer Data Format...................................................... 11 REVISION HISTORY 3/12--Rev. A to Rev. B Added Accelerometer Data Format Section and Table 6; Renumbered Sequentially.............................................................. 11 10/07--Rev. 0 to Rev. A Changes to Features and General Description ............................. 1 Added Note 6 to Table 2 .................................................................. 4 Changes to Figure 5.......................................................................... 6 Changes to Serial Interface Section and Layout ......................... 11 Changes to Layout .......................................................................... 14 Deleted Figure 24 and Table 11..................................................... 14 Changes to Converting Acceleration to Tilt Section and Second-Level Assembly Section ................................................... 15 Updated Outline Dimensions ....................................................... 16 Changes to Ordering Guide .......................................................... 16 10/05--Revision 0: Initial Version Rev. B | Page 2 of 16 Data Sheet ADIS16003 SPECIFICATIONS TA = -40C to +125C, VCC = 5 V, CX, CY = 0 F, acceleration = 0 g, unless otherwise noted. All minimum and maximum specifications are guaranteed. Typical specifications are not guaranteed. Table 1. Parameter ACCELEROMETER SENSOR INPUT Measurement Range 1 Nonlinearity Package Alignment Error Alignment Error Cross-Axis Sensitivity ACCELEROMETER SENSITIVITY Sensitivity at XFILT, YFILT Sensitivity Change due to Temperature 2 ZERO g BIAS LEVEL 0 g Voltage at XFILT, YFILT 0 g Offset vs. Temperature ACCELEROMETER NOISE PERFORMANCE Noise Density ACCELEROMETER FREQUENCY RESPONSE 3 CX, CY Range 4 RFILT Tolerance Sensor Resonant Frequency ACCELEROMETER SELF-TEST Logic Input Low Logic Input High ST Input Resistance to COM Output Change at XOUT, YOUT 5 TEMPERATURE SENSOR Accuracy Resolution Update Rate Temperature Conversion Time DIGITAL INPUT Input High Voltage (VINH) Input Low Voltage (VINL) Input Current Input Capacitance DIGITAL OUTPUT Output High Voltage (VOH) Output Low Voltage (VOL) POWER SUPPLY Operating Voltage Range Quiescent Supply Current Power-Down Current Turn-On Time 6 Conditions Each axis Min Typ Max 0.5 1.5 0.1 2 2.5 769 820 8 885 LSB/g LSB 1905 2048 0.14 2190 LSB LSB/C 1.7 % of full scale X sensor to Y sensor 5 Unit g % Degrees Degrees % Each axis Delta from 25C Each axis At 25C 110 0 24 Self-Test 0 to Self-Test 1 0.8 x VCC 30 323 VCC = 3 V to 5.25 V VCC = 4.75 V to 5.25 V VCC = 3.0 V to 3.6 V VCC = 3.0 V to 5.25 V VIN = 0 V or VCC ISOURCE = 200 A, VCC = 3.0 V to 5.25 V ISINK = 200 A 32 5.5 50 614 CX, CY = 0.1 F 1 10 40 F k kHz 0.2 x VCC V V k LSB 904 2 10 400 25 C Bits s s +1 10 V V V A pF 2.4 2.1 -10 0.8 +10 VCC - 0.5 0.4 3.0 fSCLK = 50 kSPS g/Hz rms 1.5 1.0 20 5.25 2.0 V V V mA mA ms Guaranteed by measurement of initial offset and sensitivity. Defined as the output change from ambient-to-maximum temperature or ambient-to-minimum temperature. Actual bandwidth response controlled by user-supplied external capacitor (CX, CY). 4 Bandwidth = 1/(2 x 32 k x (2200 pF + C)). For CX, CY = 0 F, bandwidth = 2260 Hz. For CX, CY = 10 F, bandwidth = 0.5 Hz. Minimum/maximum values not tested. 5 Self-test response changes as the square of VCC. 6 Larger values of CX, CY increase turn-on time. Turn-on time is approximately 160 x (0.0022 F + Cx + Cy) + 4 ms, where CX, CY are in F. 2 3 Rev. B | Page 3 of 16 ADIS16003 Data Sheet TIMING SPECIFICATIONS TA = -40C to +125C, acceleration = 0 g, unless otherwise noted. Table 2. Parameter 1, 2 fSCLK 3 tCONVERT tACQ t1 t2 4 t34 t4 t5 t6 t7 t8 5 t9 6 VCC = 3.3 V 10 2 14.5 x tSCLK 1.5 x tSCLK 10 60 100 20 20 0.4 x tSCLK 0.4 x tSCLK 80 5 VCC = 5 V 10 2 14.5 x tSCLK 1.5 x tSCLK 10 30 75 20 20 0.4 x tSCLK 0.4 x tSCLK 80 5 Unit kHz min MHz max ns min ns max ns max ns min ns min ns min ns min ns max s typ Description Throughput time = tCONVERT + tACQ = 16 tSCLK TCS/CS to SCLK setup time Delay from TCS/CS until DOUT three-state disabled Data access time after SCLK falling edge Data setup time prior to SCLK rising edge Data hold time after SCLK rising edge SCLK high pulse width SCLK low pulse width TCS/CS rising edge to DOUT high impedance Power-up time from shutdown 1 Guaranteed by design. All input signals are specified with tr and tf = 5 ns (10% to 90% of VCC) and timed from a voltage level of 1.6 V. The 3.3 V operating range spans from 3.0 V to 3.6 V. The 5 V operating range spans from 4.75 V to 5.25 V. 2 See Figure 3 and Figure 4. 3 Mark/space ratio for the SCLK input is 40/60 to 60/40. 4 Measured with the load circuit in Figure 2 and defined as the time required for the output to cross 0.4 V or 2.0 V with VCC = 3.3 V and time for an output to cross 0.8 V or 2.4 V with VCC = 5.0 V. 5 t8 is derived from the measured time taken by the data outputs to change 0.5 V when loaded with the circuit in Figure 2. The measured number is then extrapolated back to remove the effects of charging or discharging the 50 pF capacitor. This means that the time, t8, quoted in the timing characteristics is the true bus relinquish time of the part and is independent of the bus loading. 6 Shut-down recovery time denotes the time it takes to start producing samples and does not account for the recovery time of the sensor, which is dependent on the overall bandwidth. Rev. B | Page 4 of 16 Data Sheet ADIS16003 CIRCUIT AND TIMING DIAGRAMS 200A 1.6V CL 50pF 200A 05463-002 TO OUTPUT PIN IOL IOH Figure 2. Load Circuit for Digital Output Timing Specifications tACQ tCONVERT CS t6 t1 1 SCLK 2 3 t2 DOUT 4 t7 THREE-STATE 5 6 15 16 t8 t3 THREE-STATE 4 LEADING ZEROS DB9 DB10 DB11 DB0 t4 DONTC ZERO ZERO ZERO ADD0 ONE ZERO 05463-003 t5 DIN PM0 Figure 3. Accelerometer Serial Interface Timing Diagram TCS t6 1 DOUT THREESTATE 2 3 t3 LEADING ZERO 4 11 15 t7 16 t8 THREE-STATE DB9 DB8 DB0 05463-004 t1 SCLK DIN Figure 4. Temperature Serial Interface Timing Diagram Rev. B | Page 5 of 16 ADIS16003 Data Sheet ABSOLUTE MAXIMUM RATINGS Table 3. Table 4. Package Characteristics Parameter Acceleration (Any Axis, Unpowered) Acceleration (Any Axis, Powered) VCC All Other Pins Output Short-Circuit Duration (Any Pin to Common) Operating Temperature Range Storage Temperature Range Package Type 12-Terminal LGA Rating 3500 g 3500 g -0.3 V to +7.0 V (COM - 0.3 V) to (VCC + 0.3 V) JA 200C/W JC 25C/W Device Weight 0.3 grams 3.1865 8x 1.797 8x 0.670 8x 6.373 2x Stresses above those listed under 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. 3.594 4x 1.127 12x 0.500 12x 7.2mm x 7.2mm STACKED LGA. ALL DIMENSIONS IN mm. Figure 5. Second-Level Assembly Pad Layout ESD CAUTION Rev. B | Page 6 of 16 05463-023 Indefinite -40C to +125C -65C to +150C Data Sheet ADIS16003 12 TCS 11 CS VCC SCLK PIN CONFIGURATION AND FUNCTION DESCRIPTIONS 10 1 9 XFILT 8 YFILT 7 NC 3 4 5 6 ST DIN TOP VIEW (Not to Scale) NC 2 COM DOUT NC = NO CONNECT 05463-005 ADIS16003 Figure 6. Pin Configuration Table 5. Pin Function Descriptions Pin No. Mnemonic Description 1 TCS 2 DOUT 3 DIN 4 5, 7 6 8 COM NC ST YFILT 9 XFILT 10 CS 11 12 VCC SCLK Temperature Chip Select. Active low logic input. This input frames the serial data transfer for the temperature sensor output. Data Out, Logic Output. The conversion of the ADIS16003 is provided on this output as a serial data stream. The bits are clocked out on the falling edge of the SCLK input. Data In, Logic Input. Data to be written into the control register of the ADIS16003 is provided on this input and is clocked into the register on the rising edge of SCLK. Common. Reference point for all circuitry on the ADIS16003. No Connect. Self-Test Input. Active high logic input. Simulates a nominal 0.75 g test input for diagnostic purposes. Y-Channel Filter Node. Used in conjunction with an optional external capacitor to band limit the ac signal from the accelerometer. X-Channel Filter Node. Used in conjunction with an optional external capacitor to band limit the ac signal from the accelerometer. Chip Select. Active low logic input. This input provides the dual function of initiating the accelerometer conversions on the ADIS16003 and frames the serial data transfer for the accelerometer output. Power Supply Input. The VCC range for the ADIS16003 is from 3.0 V to 5.25 V. Serial Clock, Logic Input. SCLK provides the serial clock for accessing data from the part and writing serial data to the control register. This clock input is also used as the clock source for the conversion process of the ADIS16003. Rev. B | Page 7 of 16 ADIS16003 Data Sheet TYPICAL PERFORMANCE CHARACTERISTICS 40 890 35 PERCENTAGE OF POPULATION 850 830 810 790 -20 0 20 40 60 80 100 25 20 15 10 5 05463-006 770 -40 30 05463-009 SENSITIVITY (LSB/g) 870 0 1900 1929 1958 1987 2016 2045 2074 2103 2132 2161 2190 125 OUTPUT (LSB) TEMPERATURE (C) Figure 7. Sensitivity vs. Temperature (ADIS16003 Soldered to PCB) Figure 10. X-Axis Zero g Bias at 25C 2200 40 35 PERCENTAGE OF POPULATION 2100 2050 2000 1950 -20 0 20 40 60 80 100 25 20 15 10 5 05463-007 1900 -40 30 05463-010 BIAS LEVEL (LSB) 2150 0 125 1990 1929 1958 1987 2016 2045 2074 2103 2132 2161 2190 TEMPERATURE (C) OUTPUT (LSB) Figure 8. Zero g Bias vs. Temperature Figure 11. Y-Axis Zero g Bias at 25C 2200 45 40 2050 2000 1950 1900 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 35 30 25 20 15 10 05463-011 PERCENTAGE OF POPULATION 2100 05463-008 BIAS LEVEL (LSB) 2150 5 0 60 VCC (V) 70 80 90 100 110 120 130 X-AXIS NOISE DENSITY (g/ Hz) Figure 9. Zero g Bias vs. Supply Figure 12. X-Axis Noise Density at 25C Rev. B | Page 8 of 16 140 150 Data Sheet ADIS16003 40 30 20 10 0 60 70 80 90 100 110 120 130 140 50 40 30 20 10 05463-015 PERCENTAGE OF POPULATION 60 05463-012 PERCENTAGE OF POPULATION 50 0 150 350 400 450 500 550 Y-AXIS NOISE DENSITY (mg/ Hz) Figure 13. Y-Axis Noise Density at 25C 650 700 750 800 850 300 315 Figure 16. Self-Test at 25C, VCC at 5.0 V 35 45 40 25 20 15 10 05463-013 5 0 -4.5 -3.5 -2.5 -1.5 -0.5 0.5 1.5 2.5 3.5 4.5 35 30 25 20 15 10 05463-016 PERCENTAGE OF POPULATION 30 PERCENTAGE OF POPULATION 600 OUTPUT (LSB) 5 0 5.5 180 195 210 225 PERCENT SENSITIVITY (%) 240 255 270 285 OUTPUT (LSB) Figure 14. Z vs. X Cross-Axis Sensitivity Figure 17. Self-Test at 25C, VCC at 3.3 V 40 750 SELF-TEST LEVEL (LSB/g) 700 30 25 20 15 10 650 600 550 0 -4.5 -3.5 -2.5 -1.5 -0.5 0.5 1.5 2.5 3.5 4.5 450 -40 5.5 PERCENT SENSITIVITY (%) 05463-017 500 5 05463-014 PERCENTAGE OF POPULATION 35 -20 0 20 40 60 80 100 TEMPERATURE (C) Figure 15. Z vs. Y Cross-Axis Sensitivity Figure 18. Self-Test vs. Temperature, VCC at 5.0 V Rev. B | Page 9 of 16 125 ADIS16003 Data Sheet 800 90 3.3V 80 PERCENTAGE OF POPULATION 600 500 400 300 100 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 70 5V 60 50 40 30 20 10 05463-020 200 05463-018 SELF-TEST LEVEL (LSB) 700 0 1.15 1.20 1.25 1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75 VCC (V) CURRENT (A) Figure 21. Supply Current at 25C 1.8 1.0 1.7 0.8 0.6 1.5 SAMPLING ERROR (dB) 1.6 TA = +25C TA = +125C 1.4 1.3 1.2 TA = -40C 0.4 0.2 0 -0.2 -0.4 1.0 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 05463-021 -0.6 1.1 05463-019 SUPPLY CURRENT (mA) Figure 19. Self-Test vs. Supply Voltage -0.8 -1.0 1 VCC (V) 10 SAMPLE RATE (kSPS) Figure 20. Supply Current vs. Supply Voltage Figure 22. Sampling Error vs. Sample Rate Rev. B | Page 10 of 16 100 Data Sheet ADIS16003 THEORY OF OPERATION The ADIS16003 is a low cost, low power, complete dual-axis accelerometer with an integrated serial peripheral interface (SPI) and an integrated temperature sensor whose output is also available on the SPI interface. The ADIS16003 is capable of measuring acceleration with a full-scale range of 1.7 g (minimum). It can also measure both dynamic acceleration (vibration) and static acceleration (gravity). ACCELEROMETER DATA FORMAT The accelerometer data comes out in a 12-bit, offset-binary format. See Table 6 for examples of this data format. the next digital conversion is initiated. The details for the control register bit functions are shown in Table 7. Accelerometer Control Register MSB DONTC ZERO Decimal 3442 2050 2049 2048 2047 2046 654 Hex 0xD72 0x802 0x801 0x800 0x7FF 0x7FE 0x28E Binary 1101 0111 0010 1000 0000 0010 1000 0000 0001 1000 0000 0000 0111 1111 1111 0111 1111 1110 0010 1000 1110 ZERO ADD0 ONE ZERO LSB PM0 Table 7. Accelerometer Control Register Bit Functions Bit 7 6 to 4 3 Mnemonic DONTC ZERO ADD0 2 1 0 ONE ZERO PM0 Table 6. Acceleration Data Format Examples Acceleration (g) +1.7 +2/+820 +1/+820 0 -1/+820 -2/+820 -1.7 ZERO Comments Don't care. Can be 1 or 0. These bits should be held low. This address bit selects the x-axis or y-axis outputs. A 0 selects the x-axis; a 1 selects the y-axis. This bit should be held high. This bit should be held low. This bit selects the operation mode for the accelerometer; set to 0 for normal operation and 1 for power-down mode. Power Down SELF-TEST The ST pin controls the self-test feature. When this pin is set to VCC, an electrostatic force is exerted on the beam of the accelerometer. The resulting movement of the beam allows the user to test if the accelerometer is functional. The typical change in output is 750 mg (corresponding to 614 LSB) for VCC = 5.0 V. This pin can be left open-circuit or connected to common in normal use. The ST pin should never be exposed to a voltage greater than VCC + 0.3 V. If the system design is such that this condition cannot be guaranteed (for example, multiple supply voltages are present), a low VF clamping diode between ST and VCC is recommended. SERIAL INTERFACE By setting PM0 to 1 when updating the accelerometer control register, the ADIS16003 goes into a shutdown mode. The information stored in the control register is maintained during shutdown. The ADIS16003 changes modes as soon as the control register is updated. If the part is in shutdown mode and PM0 is changed to 0, the part powers up on the 16th SCLK rising edge. ADD0 By setting ADD0 to 0 when updating the accelerometer control register, the x-axis output is selected. By setting ADD0 to 1, the y-axis output is selected. ZERO ZERO is defined as the Logic low level. The serial interface on the ADIS16003 consists of five wire: CS, TCS, SCLK, DIN, and DOUT. Both accelerometer axes and the temperature sensor data are available on the serial interface. The CS and TCS are used to select the accelerometer or temperature sensor outputs, respectively. CS and TCS cannot be active at the same time. ONE ONE is defined as the Logic high level. DONTC DONTC is defined as don't care and can be a low or high logic level. The SCLK input accesses data from the internal data registers. Accelerometer Conversion Details ACCELEROMETER SERIAL INTERFACE Every time the accelerometer is sampled, the sampling function discharges the internal CX or CY filtering capacitors by up to 2% of their initial values (assuming no additional external filtering capacitors are added). The recovery time for the filter capacitor to recharge is approximately 10 s. Therefore, sampling the accelerometer at a rate of 10 kSPS or less does not induce a sampling error. However, as sampling frequencies increase above 10 kSPS, one can expect sampling errors to attenuate the actual acceleration levels. Figure 3 shows the detailed timing diagram for serial interfacing to the accelerometer in the ADIS16003. The serial clock provides the conversion clock. CS initiates the data transfer and conversion process and also frames the serial data transfer for the accelerometer output. The accelerometer output is sampled on the second rising edge of the SCLK input after the falling edge of CS. The conversion requires 16 SCLK cycles to complete. The rising edge of CS puts the bus back into three-state. If CS remains low, Rev. B | Page 11 of 16 ADIS16003 Data Sheet TEMPERATURE SENSOR SERIAL INTERFACE Temperature Sensor Conversion Details Read Operation The ADIS16003 features a 10-bit digital temperature sensor that allows an accurate measurement of the ambient device temperature to be made. Figure 4 shows the timing diagram for a serial read from the temperature sensor. The TCS line enables the SCLK input. Ten bits of data and a leading zero are transferred during a read operation. Read operations occur during streams of 16 clock pulses. The serial data is accessed in a number of bytes if 10 bits of data are being read. At the end of the read operation, the DOUT line remains in the state of the last bit of data clocked out until TCS goes high, at which time the DOUT line from the temperature sensor goes three-state. Write Operation Figure 4 also shows the timing diagram for the serial write to the temperature sensor. The write operation takes place at the same time as the read operation. Data is clocked into the control register on the rising edge of SCLK. DIN should remain low for the entire cycle. Temperature Sensor Control Register MSB ZERO ZERO ZERO ZERO ZERO ZERO ZERO LSB ZERO Table 8. Temperature Sensor Control Register Bit Functions Bit 7 to 0 Mnemonic ZERO Comments All bits should be held low. ZERO ZERO is defined as the Logic low level. Output Data Format The output data format for the temperature sensor is twos complement. Table 9 shows the relationship between the temperature and the digital output. Table 9. Temperature Sensor Data Format Temperature -40C -25C -0.25C 0C +0.25C +10C +25C +50C +75C +100C +125C Digital Output (DB9 ... DB0) 11 0110 0000 11 1001 1100 11 1111 1111 00 0000 0000 00 0000 0001 00 0010 1000 00 0110 0100 00 1100 1000 01 0010 1100 01 1001 0000 01 1111 0100 The conversion clock for the temperature sensor is internally generated so no external clock is required except when reading from and writing to the serial port. In normal mode, an internal clock oscillator runs the automatic conversion sequence. A conversion is initiated approximately every 350 s. At this time, the temperature sensor wakes up and performs a temperature conversion. This temperature conversion typically takes 25 s, at which time the temperature sensor automatically shuts down. The result of the most recent temperature conversion is available in the serial output register at any time. Once the conversion is finished, an internal oscillator starts counting and is designed to time out every 350 s. The temperature sensor then powers up and does a conversion. If the TCS is brought low every 350 s (30%) or less, the same temperature value is output onto the DOUT line every time without changing. It is recommended that the TCS line not be brought low every 350 s (30%) or less. The 30% covers process variation. The TCS should become active (high to low) outside this range. The device is designed to autoconvert every 350 s. If the temperature sensor is accessed during the conversion process, an internal signal is generated to prevent any update of the temperature value register during the conversion. This prevents the user from reading back spurious data. The design of this feature results in this internal lockout signal being reset only at the start of the next autoconversion. Therefore, if the TCS line goes active before the internal lockout signal is reset to its inactive mode, the internal lockout signal is not reset. To ensure that no lockout signal is set, bring TCS low at a greater time than 350 s (30%). As a result, the temperature sensor is not interrupted during a conversion process. In the automatic conversion mode, every time a read or write operation takes place, the internal clock oscillator is restarted at the end of the read or write operation. The result of the conversion is typically available 25 s later. Reading from the device before conversion is complete provides the same set of data. POWER SUPPLY DECOUPLING For most applications, a single 0.1 F capacitor (CDC) adequately decouples the accelerometer from noise on the power supply. However, in some cases, particularly where noise is present at the 140 kHz internal clock frequency (or any harmonic thereof), noise on the supply can cause interference on the ADIS16003 output. If additional decoupling is needed, ferrite beads can be inserted in the supply line of the ADIS16003. Additionally, a larger bulk bypass capacitor (in the 1 F to 22 F range) can be added in parallel to CDC. Rev. B | Page 12 of 16 Data Sheet ADIS16003 SETTING THE BANDWIDTH The ADIS16003 has provisions for band limiting the accelerometer. Capacitors can be added at the XFILT pin and the YFILT pin to implement further low-pass filtering for antialiasing and noise reduction. The equation for the 3 dB bandwidth is f-3dB = 1/(2(32 k) x (C(XFILT, YFILT) + 2200 pF)) f-3dB = 5 F/(C(XFILT, YFILT) + 2200 pF) The tolerance of the internal resistor (RFILT) can vary typically as much as 25% of its nominal value (32 k); thus, the bandwidth varies accordingly. A minimum capacitance of 0 pF for CXFILT and CYFILT is allowable. Table 10. Filter Capacitor Selection, CXFILT and CYFILT Capacitor (F) 4.7 0.47 0.10 0.047 0.022 0.01 0 The accelerometer bandwidth selected ultimately determines the measurement resolution (smallest detectable acceleration). Filtering can be used to lower the noise floor, which improves the resolution of the accelerometer. Resolution is dependent on the analog filter bandwidth at XFILT and YFILT. The ADIS16003 has a typical bandwidth of 2.25 kHz with no external filtering. The analog bandwidth can be further decreased to reduce noise and improve resolution. or more simply, Bandwidth (Hz) 1 10 50 100 200 400 2250 SELECTING FILTER CHARACTERISTICS: THE NOISE/BANDWIDTH TRADE-OFF The ADIS16003 noise has the characteristics of white Gaussian noise, which contributes equally at all frequencies and is described in terms of g/Hz (that is, the noise is proportional to the square root of the bandwidth of the accelerometer). The user should limit bandwidth to the lowest frequency needed by the application to maximize the resolution and dynamic range of the accelerometer. With the single-pole, roll-off characteristic, the typical noise of the ADIS16003 is determined by rmsNoise = (110 g/Hz) x ((BW x 1.6)) At 100 Hz, the noise is rmsNoise = (110 g/Hz) x ((100 x 1.6)) =1.4 mg Often, the peak value of the noise is desired. Peak-to-peak noise can only be estimated by statistical methods. Table 11 is useful for estimating the probabilities of exceeding various peak values, given the rms value. Table 11. Estimation of Peak-to-Peak Noise Peak-to-Peak Value 2 x rms 4 x rms 6 x rms 8 x rms Rev. B | Page 13 of 16 Percentage of Time Noise Exceeds Nominal Peak-to-Peak Value (%) 32 4.6 0.27 0.006 ADIS16003 Data Sheet 10 7 3 9 4 2 DIGITAL OUTPUT (IN LSBs) X-AXIS: 2867 Y-AXIS: 2048 DIGITAL OUTPUT (IN LSBs) X-AXIS: 2048 Y-AXIS: 2048 1 8 8 3 5 7 6 9 10 11 12 05463-024 2 DIGITAL OUTPUT (IN LSBs) X-AXIS: 2048 Y-AXIS: 1229 10 5 4 1 1 6 12 Top View Not to Scale 5 DIGITAL OUTPUT (IN LSBs) X-AXIS: 2048 Y-AXIS: 2867 2 12 6 3 4 11 6 7 10 8 5 11 4 9 8 7 DIGITAL OUTPUT (IN LSBs) X-AXIS: 1229 Y-AXIS: 2048 3 2 9 11 1 12 Figure 23. Output Response vs. Orientation Rev. B | Page 14 of 16 Data Sheet ADIS16003 APPLICATIONS INFORMATION DUAL-AXIS TILT SENSOR Converting Acceleration to Tilt One of the most popular applications of the ADIS16003 is tilt measurement. An accelerometer uses the force of gravity as an input vector to determine the orientation of an object in space. An accelerometer is most sensitive to tilt when its sensitive axis is perpendicular to the force of gravity, that is, parallel to the earth's surface. At this orientation, its sensitivity to changes in tilt is highest. When the accelerometer is oriented on axis to gravity, near its +1 g or -1 g reading, the change in output acceleration per degree of tilt is negligible. When the accelerometer is perpendicular to gravity, its output changes nearly 17.5 mg per degree of tilt. At 45, its output changes at only 12.2 mg per degree and its resolution declines. When the accelerometer is oriented, so both its x-axis and y-axis are parallel to the earth's surface, it can be used as a 2-axis tilt sensor with a roll axis and a pitch axis. Once the output signal from the accelerometer is converted to an acceleration that varies between -1 g and +1 g, the output tilt in degrees is calculated as follows: PITCH = Asin(AX/1 g) ROLL = Asin(AY/1 g) where: AX is the acceleration along the x-axis. AY is the acceleration along the y-axis. Be sure to account for overranges. It is possible for the accelerometers to output a signal greater than 1 g due to vibration, shock, or other accelerations. SECOND LEVEL ASSEMBLY The ADIS16003 can be attached to the second level assembly board using SN63 (or equivalent) or lead-free solder. IPC/ JEDEC J-STD-020 and J-STD-033 provide standard handling procedures for these types of packages. Rev. B | Page 15 of 16 ADIS16003 Data Sheet OUTLINE DIMENSIONS 3.594 BSC (4x) 1.797 BSC (8x) 7.35 MAX 10 PIN 1 INDICATOR 7.20 TYP 1 6 .373 BSC (2x) 7 3 6 TOP VIEW 1.00 BSC (12x) 12 9 0.200 MIN (ALL SIDES) 4 BOTTOM VIEW 0.797 BSC (8x) 0.373 BSC (12x) 5.00 TYP 092407-C 3.70 MAX SIDE VIEW Figure 24. 12-Terminal Land Grid Array [LGA] (CC-12-1) Dimensions shown in millimeters ORDERING GUIDE Model 1 ADIS16003CCCZ ADIS16003/PCBZ 1 Temperature Range -40C to +125C Package Description 12-Terminal Land Grid Array (LGA) Evaluation Board Z = RoHS Compliant Part. (c)2005-2012 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05463-0-3/12(B) Rev. B | Page 16 of 16 Package Option CC-12-1 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Analog Devices Inc.: ADIS16003/PCBZ ADIS16003CCCZ