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compact, precision ten degrees of freedom inertial sensor data sheet adis16448 rev. b 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. specif ications 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 C 2013 analog devices, inc. all rights reserved. technical support www.analog.com features triaxial digital gyroscope with digital range scaling 250 /sec, 50 0/sec, 10 00/sec settings axis - to - axis align ment, <0.05 triaxial digital accelerometer, 18 g minimum triaxial digital magnetometer, 1.9 gauss minimum digital b arometer , 10 mb ar to 1200 mbar calibrated pressure range: 3 00 mbar to 1100 mbar autonomous operation and data collection no external configuration commands required 205 ms start - up time factory calibrated sensitivity, bias, and axial alignment calibration t emperature ran ge: ?40c to + 70 c spi - compatible serial interface embedded temperature sensor programmable operation and control automatic and manual bias correction controls bartlett window fir length, number of taps digital i/o: data ready, alarm indicator, general - pu rpose alarms for condition monitoring enable external sample clock input up to 1. 1 khz single command self test single - supply operation: 3. 15 v to 3. 45 v 2000 g shock survivability operating temperature range: ?40c to + 85c applications platform stabiliza tion and control navigation robotics general description the adis16448 i sensor ? device i s a complete inertial system that include s a triaxial gyroscope , a triaxial accelerometer , a triaxial magnetometer , and pressure sensor s . each sensor in the adis16448 c ombines industry - leading i mems? technology with signal conditioning that optimizes dynamic performance. the factory calibrati on characterizes each sensor for sensitivity, bias, alignment, and linear acceleration (gyro scope bias). as a result, each sensor has its own dynamic compensation formulas that provide accurate sensor measurements. the adis16448 provide s a simple, cost - effective method for integrating accurate, multiaxis inertial sensing into industrial systems, especially when compared with the complexity and investment associated with discrete designs. all n ecessary motion testing and calibration are part of the production process at the factory, greatly reducing system integration time. tight orthogonal alignment simplifies inertial frame alignment in navigation systems. the spi and register structure s provi de a simple interface for data collection and configuration control. the adis16448 has a compatible pinout for systems that currently use other a nalog d evices, i nc., imu products (adis163xx/ adis16 4xx). the adis16448 is packaged in a module that is approximately 24.1 mm 37.7 mm 10.8 mm and has a standard connector interface. functional block dia gram controlller clock triaxial gyro triaxial accel power management cs sclk din dout gnd vdd temp vdd dio1 dio2 dio3 dio4/clkin rst spi triaxial magn pressure self test i/o alarms output data registers user control registers calibration and filters adis16448 09946-001 figure 1.
adis16448 data sheet rev. b | page 2 of 24 table of contents features .............................................................................................. 1 applications ....................................................................................... 1 general des cription ......................................................................... 1 functional block diagram .............................................................. 1 revision history ............................................................................... 2 specifi cations ..................................................................................... 3 timing specifications .................................................................. 5 absolute maximum ratings ............................................................ 6 esd caution .................................................................................. 6 pin configuration and function descriptions ............................. 7 typical performance characteristics ............................................. 8 user registers .................................................................................... 9 user interface .................................................................................. 10 reading sensor data .................................................................. 10 device configuration ................................................................ 11 output data registers .................................................................... 12 gyroscopes .................................................................................. 12 accelerometers ............................................................................ 12 magnetometers ........................................................................... 13 barometric pressure ................................................................... 13 remote pressure sensing ........................................................... 13 internal temperature ................................................................. 13 system functions ............................................................................ 14 global commands ..................................................................... 14 product identification ................................................................ 14 self - test function ....................................................................... 14 status/error flags ....................................................................... 15 memory management ............................................................... 15 input/output configuration ......................................................... 16 data ready indicator ................................................................. 16 general - purpose input/output ................................................ 16 digital processing configuration ................................................. 17 gyroscopes/accelerometers ..................................................... 17 input clock configuration ....................................................... 17 magne tometer/barometer ......................................................... 18 calibration ....................................................................................... 19 gyroscopes .................................................................................. 19 accelerometers ........................................................................... 19 magnetometer calibration ........................................................ 20 flash updates .............................................................................. 20 restoring facto ry calibration .................................................. 20 alarms .............................................................................................. 21 static alarm use ......................................................................... 21 dynamic alarm us e .................................................................. 21 alarm reporting ........................................................................ 21 applications information .............................................................. 22 power supply considerations ................................................... 22 adis16448/pcbz ...................................................................... 22 pc - based evaluation tools ....................................................... 22 outline dimensions ....................................................................... 23 ordering guide .......................................................................... 23 revision history 7 /13 rev. a to rev. b change s to linear acceleration effect on bias te st conditions ... 3 changes burst read function to section .................................... 1 1 3 /13 rev. 0 to rev. a change d start - up time from 192 ms to 205 ms ......................... 1 changes to table 1 ............................................................................ 3 change d vdd from 5 v to 3.3 v, changed t stall from 1/f sclk to n/a, and added endnote 2; table 2 .............................................. 5 changes to burst read function section .................................... 1 1 changes to table 23 ........................................................................ 1 3 changes to single command bias correction section ............. 1 9 changes to adis16448/pcbz section ........................................ 2 2 deleted mounting, approaches section ...................................... 2 2 updated outline dimensions ....................................................... 23 changes to ordering guide .......................................................... 23 8 / 1 2 revision 0: initial version
data sheet adis16448 rev. b | page 3 of 24 specific ations t a = 2 5c, v dd = 3.3 v, angular rate = 0/s ec, dynamic range = 1 0 0 0/s ec 1 g , unless otherwise noted. table 1 . parameter test conditions /comments min typ max unit gyroscopes dynamic range 1000 1200 /sec initi al sensitivity 10 00/sec , se e table 12 0.0 4 /sec/lsb 50 0/sec , se e table 12 0.0 2 /sec/lsb 250 /sec , se e table 12 0.01 /sec/lsb repeatability 1 ? 40c t a +70 c 1 % sensitivity temperature coefficient ? 40c t a + 70 c 40 ppm/c misalignment axis to axis 0.05 degrees axis to frame (package) 0.5 degrees nonlinearity best fit straight line 0.1 % of fs bias repeatability 1 , 2 ? 40c t a +70c, 1 0.5 /sec in - run bias stability 1 , smpl_prd = 0x0001 14.5 /hr angular random walk 1 , smpl_prd = 0x0001 0. 6 6 /hr bias temperature coefficient ? 40c t a +70c 0.005 /sec/c linear acceleration effec t on bias any axis, 1 0. 015 /sec/ g bias supply sensitivity ? 40c t a +70c 0.2 /sec/v output noise 1 0 00/sec range, no filtering 0 .2 7 /sec rms rate noise density f = 25 hz, 10 00/sec range, no filtering 0.01 35 /sec/hz rms ? 3 db ban dwidth 330 hz sensor resonant frequency 17.5 khz accelerometers each axis dynamic range 18 g sensitivity see table 16 for data format 0.833 m g /lsb repeatability 1 ? 40c t a +7 0c 1 % sensitivity temperature coefficient ? 40c t a +70c 4 0 ppm/c misalignment axis to axis 0.2 degrees axis to frame (package) 0.5 degrees nonlinearity best fit straight line 0.2 % of fs bias repeatability 1 , 2 ? 40c t a +70c, 1 20 m g in - run bias stability 1 , smpl_prd = 0x0001 0. 2 5 m g velocity random walk 1 , smpl_prd = 0x0001 0.11 m/sec/hr bias temperature coefficient ? 40c t a + 70 c 0. 15 m g /c bias supply sensitivity ? 40c t a +70c 5 mg/v output noise no filtering 5.1 m g rms noise density no filtering 0.23 m g /hz rms ? 3 db bandwidth 330 hz sensor resonant frequency 5.5 khz magnetometers dynamic range 1.9 gauss ini tial sensitivity 25c, see table 20 for data format 140.04 142.9 145.76 gauss/lsb sensitivity temperature coefficient relative to 25c, 1 800 ppm/c misalignment axis to axis 0.25 degrees axis to frame (package) 0.5 degrees nonlinearity best fit straight line 0.1 % of fs initial bias error 25c, 0 gauss stimulus 4 mgauss bias temperature coefficient ? 40c t a +70c 0.11 mgauss/c output noise 25c, no filtering, rms 2.4 mgauss noise density 25c, no f iltering, rms 0.4 mgauss/hz bandwidth ? 3 db 25 hz
adis16448 data sheet rev. b | page 4 of 24 parameter test conditions /comments min typ max unit temperature sensitivity see table 23 0.07386 c/lsb barometers pressure range, operating 300 1100 mbar pressure range extended 3 10 1200 mbar sensitivit y 0.02 mbar/lsb voltage dependence 0.18 %/v bias supply voltage sensitivity 3.24 mbar/v total error 25c, 300 mbar to 1100 mbar 1.5 mbar relative error 4 ? 40c to +85c, 300 mbar to 1100 mbar 2.5 mbar linearity 5 25c, 300 mbar to 1100 mbar 0.1 % of fs ? 40c to +85c, 300 mbar to 1100 mbar 0.2 % of fs noise 0.08 mbar rms logic inputs 6 input high voltage, v ih 2.0 v input low voltage, v il 0.8 v logic 1 input current, i ih v ih = 3.3 v 0.2 10 a logic 0 input curren t, i il v il = 0 v all pins except rst 40 60 a rst pin 1 ma input capacitance, c in 10 pf digital outputs 6 output high voltage, v oh i source = 1.6 ma 2.4 v output l ow voltage, v ol i sink = 1.6 ma 0.4 v flash memory endurance 7 10,000 cycles data retention 8 t j = 85c 20 years functional times 9 time until new data is available power - on start - up time 205 ms reset recovery time 10 90 ms flash memory bac k - up time 75 ms flash memory test time 20 ms automatic self - test time smpl_prd = 0x0001 45 ms conversion rate xgyro_out, xaccl_out smpl_prd = 0x0001 819.2 sps xmagn_out, bar o _out 11 smpl_prd = 0x0001 51.2 sps clock accuracy 3 % sy nc input clock 12 0.8 1.1 khz power supply operating voltage range, vdd 3.15 3.3 3.45 v power supply current 76 104 ma 1 the repeatability specific ations represent analytical projections, which are based off of the following drift contributions and conditions: temperature hysteresis ( ? 40c to +70c), electronics drift (high - te mperature operating life test: 85c, 500 hours), drift from temperature cycling (jesd22, method a104 - c, method n, 500 cycles, ? 40c to +85c), rate random walk (10 year projection), and broadband noise . 2 bias rep eatability describes a long - term behavior, over a variety of conditions. short - term repeatability is related to the in - run bias stability and noise density specifications. 3 the extended pressure range is guaranteed by design. 4 the relative error assumes that the initial error, at 25c, is corrected in the end application. 5 linearity errors assume a full scale (fs) of 1000 mbar. 6 the digital i/o signals are driven by an internal 3.3 v supply , and the inputs are 5 v tolerant. 7 endurance is qualified as p er jedec standard 22 , method a117 , and measured at ? 40c , +25 c , +85 c, and +125 c . 8 the data r etention lifetime equivalent is at a junction temperature (t j ) of 8 5 c as per jedec s tandard 22, method a117. data r etention lifetime decreases with junction te mperature. 9 these times do not include thermal settling and internal filter response times (330 hz bandwidth), which may affect overall a ccuracy. 10 the rst line must be held low for at least 10 s to assure a proper reset and recovery se quence. 11 the xmagn_out and baro_out registers update at a rate that is 1/16 th that of the other output registers. 12 the sync input clock functions below the specified minimum value but at reduced performance levels.
data sheet adis16448 rev. b | page 5 of 24 timing specifications t a = 25c, vdd = 3.3 v, unless otherwise noted. table 2. parameter description normal mode burst read unit min 1 typ max min 1 typ max f sclk serial clock 0.01 2.0 0.01 1.0 mhz t stall stall period between data 9 n/a 2 s t readrate read rate 40 s t cs chip select to sclk edge 48.8 48.8 ns t dav dout valid after sclk edge 100 100 ns t dsu din setup time before sclk rising edge 24.4 24.4 ns t dhd din hold time after sclk rising edge 48.8 48.8 ns t sclkr , t sclkf sclk rise/fall times, not shown in timing diagrams 5 12.5 5 12.5 ns t dr , t df dout rise/fall times, not shown in timing diagrams 5 12.5 5 12.5 ns t sfs cs high after sclk edge 5 5 ns t 1 input sync positive pulse width 25 5 s t stdr input sync to data ready valid transition 685 685 s t nv data invalid time 210 210 s t 3 input sync period 910 910 s 1 guaranteed by design and characterization, but not tested in production. 2 when using the burst read mode, the stall period is not applicable. timing diagrams cs sclk dout din 1 2 3 4 5 6 15 16 r/w a5 a6 a4 a3 a2 d2 msb db14 d1 lsb db13 db12 db10 db11 db2 lsb db1 t cs t sfs t dav t dhd t dsu 09946-002 figure 2. spi timing and sequence cs sclk t readr ate t stall 09946-003 figure 3. stall time and data rate cloc k data ready t 1 t 3 t nv t stdr 09946-004 figure 4. input clock timing diagram
adis16448 data sheet rev. b | page 6 of 24 absolute maximum rat ings table 3 . parameter rating acceleration any axis, unpowered 2000 g any axis, powered 2000 g vdd to gnd ? 0 .3 v to + 3. 45 v digital input voltage to gnd ? 0.3 v to + vdd + 0.3 v digital output voltage to gnd ? 0.3 v to + vdd + 0.3 v temperature operating range ? 40c to + 8 5c storage range ? 65 c to +125c 1, 2 pressure 2 bar 1 extended exposure to temperature s outside the specified temperature range of ?40c to +105c can adversely affect the accuracy of the factory calibration. for best accuracy, store the parts within the specified operating range of ?40c to +105c. 2 although the device is capable of withs tanding short - term exposure to 150c, long - term exposure threatens internal mechanical integrity. stresses above those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only; functional operation of th e 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. table 4 . package characteristics package type ja (c/w) jc (c/w) mass (grams) 2 0 - lead module (ml -2 0 -2 ) 36.5 16.9 1 5 esd caution
data sheet adis16448 rev. b | page 7 of 24 pin configuration an d function descripti ons 19 dio4/clkin dout cs rst vdd dio2 gnd dnc dnc dnc dio3 sclk din dio1 vdd vdd gnd gnd dnc dnc 20 17 18 15 16 13 14 11 12 9 10 7 8 5 6 3 4 1 2 adis16448 top view (not to scale) notes 1. this representation displays the top view when the connector is visible and facing up. 2. mating connector: samtec clm-110-02 or equivalent. 3. dnc = do not connect. 09946-005 figure 5 . pin configuration pin 1 pin 20 use this opening for remote pressure sensing. hole is t apped for 10-32 screw threads. 09946-106 figure 6. pin locations table 5 . pin function descriptions pin no. mnemonic type 1 description 1 dio3 i/o configurable digital input/output. 2 dio4/clkin i/o configurable digital input/output or sync clock input. 3 sclk i spi serial clock. 4 dout o spi data output. clocks the output on the sclk falling edge. 5 din i spi data input. clocks the input on the sclk rising edge. 6 cs i spi chip select. 7 dio1 i/o configurable digital input/output. 8 rst i reset. 9 dio2 i/o configurable digital input/output. 10, 11, 12 vdd s power supply. 13, 14, 15 gnd s power ground. 16, 17, 18, 19 , 20 dnc n/a do not connect. do not connect to these pins. 1 s is supply, o is output, i is input, n/a is not applicable.
adis16448 data sheet rev. b | page 8 of 24 typical performance characteristics 1 10 100 1000 0.01 0.1 1 10 100 1000 root allan v ariance (/hour) t au (seconds) C + average 09946-127 figure 7 . gyroscope root allan variance 0.01 0.1 1 10 0.01 0.1 1 10 100 1000 root allan v ariance (mg) t au (seconds) average C + 09946-128 figure 8 . accelerometer root allan variance
data sheet adis16448 rev. b | page 9 of 24 user registers table 6 . user register memory map 1 name r/w flash backup address 2 defau lt function bit assignments flash_cnt r yes 0x00 n/a flash memory write count see table 32 reserved n/a n/a 0x02 n/a n/a xgyro_out r no 0x04 n/a x - axis gyroscope output see table 9 ygyro_out r no 0 x06 n/a y - axis gyroscope output see table 10 zgyro_out r no 0x08 n/a z - axis gyroscope output see table 11 xaccl_out r no 0x0a n/a x - axis accelerometer output see table 13 y accl_out r no 0x0c n/a y - axis accelerometer output see table 14 zaccl_out r no 0x0e n/a z - axis accelerometer output see table 15 xmagn_out r no 0x10 n/a x - axis magnetometer measurement see table 17 ymagn_out r no 0x12 n/a y - axis magnetometer measurement see table 18 zmagn_out r no 0x14 n/a z - axis magnetometer measurement see table 19 baro_out r no 0x16 n/a barometer pre ssure measurement, high word see table 21 temp_out r no 0x18 n/a temperature output see table 23 xgyro_off r/w yes 0x1a 0x0000 x - axis gyroscope bias offset factor see table 37 ygyro_off r/w yes 0x1c 0x0000 y - axis gyroscope bias offset factor see table 38 zgyro_off r/w yes 0x1e 0x0000 z - axis gyroscope bias offset factor see table 39 xaccl_off r/w yes 0x20 0x0000 x - axis acceleration bias offset factor see table 40 yaccl_off r/w yes 0x22 0x0000 y - axis acceleration bias offset factor see table 41 zaccl_off r/w yes 0x24 0x0000 z - axis acceleration bias offset factor see table 42 xmagn_hic r/w yes 0x26 0x0000 x - axis magnetometer, hard iron factor see table 43 ymagn_hic r/w yes 0x28 0x0000 y - axis magnetometer, hard iron factor see table 44 z magn_hic r/w yes 0x2a 0x0000 z - axis magnetometer, hard iron factor see table 45 xmagn_sic r/w yes 0x2c 0x0 0 00 x - axis magnetometer, soft iron factor see table 46 ymagn_sic r/w yes 0x2e 0x0 0 00 y - axis ma gnetometer, soft iron factor see table 47 zmagn_sic r/w yes 0x30 0x0 0 00 z - axis magnetometer, soft iron factor see table 48 gpio_ctrl r/w no 0x32 0x0000 auxiliary digital input/output control see table 33 msc_ctrl r/w yes 0x34 0x0006 miscellaneous control see table 30 smpl_prd r/w yes 0x36 0x0001 internal sample period (rate) control see table 34 sens_avg r/w yes 0x38 0x0402 dynamic range and digital filter control see table 35 seq_cnt r n/a 0x3a n/a xmagn_out and bar o _out counter see table 36 diag_stat r no 0x3c 0x0000 system status see ta ble 31 glob_cmd w n/a 0x3e 0x0000 system command see table 25 alm_mag1 r/w yes 0x40 0x0000 alarm 1 amplitude threshold see table 49 alm_mag2 r/w yes 0x42 0x0000 alarm 2 amplitude threshold see table 50 alm_smpl1 r/w yes 0x44 0x0000 alarm 1 sample size see table 51 alm_smpl2 r/w yes 0x46 0x0000 alarm 2 sample size see table 52 alm_ctrl r/w yes 0x48 0x0000 alarm con trol see table 53 reserved n/a n/a 0x4a to 0x51 n/a reserved lot_id1 r yes 0x52 n/a lot identification number see table 26 lot_id2 r yes 0x54 n/a lot identification number see table 27 prod_id r yes 0x56 0x4040 product identifier see table 28 serial_num r yes 0x58 n/a lot - specific serial number see table 29 1 n/a means not applicable. 2 each register contains two bytes. the address of the lowe r byte is displayed. the address of the upper byte is equal to the address of the lower byte plus 1.
adis16448 data sheet rev. b | page 10 of 24 user interface the adis16448 is an autonomous system that requires no user initialization. when it has a valid power supply, it initializes itself and starts sampling, processing, and loading sensor data into the output registers at a sample rate of 819.2 sps. dio1 pulses high after each sample cycle concludes. the spi interface enables simple integration with many embedded processor platforms, as shown in figure 9 (electrical connection) and table 7 (pin functions). system processor spi master adis16448 sclk cs din dout sclk ss mosi miso +3.3 v irq dio1 vdd i/o lines are compatible with 3.3v or 5v logic levels 10 6 3 5 4 7 11 12 13 14 15 09946-009 10f figure 9. electrical connection diagram table 7. generic master processor pin names and functions pin name function ss slave select sclk serial clock mosi master output, slave input miso master input, slave output irq interrupt request the adis16448 spi interface supports full duplex serial commu- nication (simultaneous transmit and receive) and uses the bit sequence shown in figure 12. table 8 provides a list of the most common settings that require attention to initialize the serial port of a processor for the adis16448 spi interface. table 8. generic master processor spi settings processor setting description master the adis16448 operates as a slave sclk rate 2 mhz 1 maximum serial clock rate spi mode 3 cpol = 1 (polarity), cpha = 1 (phase) msb-first mode bit sequence 16-bit mode shift register/data length 1 for burst read, sclk rate 1 mhz. reading sensor data the adis16448 provides two different options for acquiring sensor data: single register and burst register. a single register read requires two 16-bit spi cycles. the first cycle requests the contents of a register using the bit assignments in figure 12. bit dc7 to bit dc0 are dont cares for a read, and then the output register contents follow on dout during the second sequence. figure 10 includes three single register reads in succession. in this example, the process starts with din = 0x0400 to request the contents of xgyro_out, then follows with 0x0600 to request ygyro_out and 0x0800 to request zgyro_out. full duplex operation enables processors to use the same 16-bit spi cycle to read data from dout while requesting the next set of data on din. figure 11 provides an example of the four spi signals when reading xgyro_out in a repeating pattern. xgyro_out din dout ygyro_out zgyro_out 0x0400 0x0600 0x0800 09946-010 figure 10. spi read example sclk cs din dout 09946-111 dout = 1111 10011101 1010 = 0xf9da = ?1574 lsbs ?62.96/sec din = 0000 0100 0000 0000 = 0x0400 figure 11. example spi read , second 16-bit sequence r/w r/w a6 a5 a4 a3 a2 a1 a0 dc7 dc6 dc5 dc4 dc3 dc2 dc1 dc0 d0d1d2 d3 d4d5d6d7d8d9 d10 d11 d12 d13d14 d15 cs sclk din dout a6 a5 d13 d14 d15 notes 1. the dout bit pattern reflects the entire contents of the register identified by [a6:a0] in the previous 16-bit din sequence when r/w = 0. 2. if r/w = 1 during the previous sequence, dout is not defined. 09946-013 figure 12. spi communication bit sequence
data sheet adis16448 rev. b | page 11 of 24 burst read function the burst read function provides a way to read all of the data in one continuous stream of bits (no stall time). as shown in figure 13, start this mode by setting din = 0x3e00, while keeping cs low for 12 additional, 16-bit read cycles. these 12 cycles produce the following sequence of output registers on dout: diag_stat, xgyro_out, ygyro_out, zgyro_out, xaccl_out, yaccl_out, zaccl_out, xmagn_out, ymagn_out, zmagn_out, baro_out, and temp_out. glob_cmd cs sclk din dout xgyro_out diag_stat temp_out 1231 3 09946-113 figure 13. burst read sequence spi read test sequence figure 14 provides a test pattern for testing the spi communica- tion. in this pattern, write 0x5600 to the din line in a repeating pattern and raise chip select for at least 9 s between each 16-bit sequence. starting with the second 16-bit sequence, dout produces the contents of the prod_id (see table 28) register, 0x4040. dout = 0100 0000 0100 0000 = 0x4040 = 16,448 din = 0101 0110 0000 0000 = 0x5600 sclk cs din dout 09946-011 figure 14. spi test read pattern din = 0x5600, dout = 0x4040 device configuration the control registers in table 6 provide users with a variety of configuration options. the spi provides access to these registers, one byte at a time, using the bit assignments in figure 12. each register has 16 bits, where bits[7:0] represent the lower address, and bits[15:8] represent the upper address. figure 15 provides an example of writing 0x04 to address 0x36 (smpl_prd[15:8], using din = 0xb704. this example reduces the sample rate by a factor of eight (see table 34). sclk cs din din = 1011 0111 0000 0100 = 0xb704, writes 0x04 to address 0x37. 09 946-016 figure 15. example spi write sequence dual memory structure writing configuration data to a control register updates its sram contents, which are volatile. after optimizing each relevant control register setting in a system, set glob_cmd[3] = 1 (din = 0xbe08) to backup these settings in nonvolatile flash memory. the flash backup process requires a valid power supply level for the entire process time, 75 ms. table 6 provides a user register memory map that includes a flash backup column. a yes in this column indicates that a register has a mirror location in flash and, when backed up properly, it automatically restores itself during startup or after a reset. figure 16 provides a diagram of the dual memory structure used to manage operation and store critical user settings. nonvolatile flash memory (no spi access) manual flash backup start-up reset volatile sram spi access 09946-017 figure 16. sram and flash memory diagram
adis16448 data sheet rev. b | page 12 of 24 output data registers each sensor in the adis16448 has a dedicated output register in the user register map (see table 6). figure 17 provides arrows, which describe the direction or rotation (g x , g y , g z ), acceleration (a x , a y , a z ), and magnetic field (m x , m y , m z ) that will produce a positive response in its output data. gyroscopes xgyro_out (see table 9) contains x-axis gyroscope data (g x in figure 17), ygyro_out (see table 10) contains y-axis gyro- scope data (g y in figure 17), and zgyro_out (see table 11) contains z-axis gyroscope data (g z in figure 17). table 12 illustrates the gyroscope data format with numerical examples. table 9. xgyro_out (base a ddress = 0x04), read only bits description [15:0] x-axis gyroscope data, twos complement format, 25 lsb//sec (sens_avg[15:8] = 0x04), 0/sec = 0x0000 table 10. ygyro_out (base address = 0x06), read only bits description [15:0] y-axis gyroscope data, twos complement format, 25 lsb//sec (sens_avg[15:8] = 0x04), 0/sec = 0x0000 table 11. zgyro_out (base address = 0x08), read only bits description [15:0] z-axis gyroscope data, twos complement format, 25 lsb//sec (sens_avg[15:8] = 0x04), 0/sec = 0x0000 table 12. rotation rate, twos complement format 1 rotation rate (/sec) decimal hex binary +1000 +25,000 0x61a8 0110 0001 1010 1000 +2 25 +2 0x0002 0000 0000 0000 0010 +1 25 +1 0x0001 0000 0000 0000 0001 0 0 0x0000 0000 0000 0000 0000 ?1 25 ?1 0xffff 1111 1111 1111 1111 ?2 25 ?2 0xfffe 1111 1111 1111 1110 ?1000 ?25,000 0x9e58 1001 1110 0101 1000 1 sens_avg[15:8] = 0x 04, see table 35. accelerometers xaccl_out (see table 13) contains x-axis accelerometer data (a x in figure 17), yaccl_out (see table 14) contains y-axis accelerometer data (a y in figure 17), and zaccl_out (see table 15) contains z-axis accelerometer data (a z in figure 17). table 16 illustrates the accelerometer data format with numerical examples. table 13. xaccl_out (base address = 0x0a), read only bits description [15:0] x-axis acceleration data, twos complement format, 1200 lsb/ g , 0 g = 0x0000 table 14. yaccl_out (base address = 0x0c), read only bits description [15:0] y-axis acceleration data, twos complement format, 1200 lsb/ g , 0 g = 0x0000 table 15. zaccl_out (base address = 0x0e), read only bits description [15:0] z-axis acceleration data, twos complement format, 1200 lsb/ g , 0 g = 0x0000 table 16. acceleration, twos complement format acceleration ( g ) decimal hex binary +18 +21,600 0x5460 0101 0100 0101 0000 +2 1200 +2 0x0002 0000 0000 0000 0010 +1 1200 +1 0x0001 0000 0000 0000 0001 0 0 0x0000 0000 0000 0000 0000 ?1 1200 ?1 0xffff 1111 1111 1111 1111 ?2 1200 ?2 0xfffe 1111 1111 1111 1110 ?18 ?21,600 0xaba0 1010 1011 1010 0000 y -axis x-axis z-axis 09946-206 a z m z a y m y g y a x m x g x g z figure 17. inertial sensor direction reference
data sheet adis16448 rev. b | page 13 of 24 magnetometers xmagn_out ( see table 17 ) contains x - axis magnetometer data (m x in figure 17 ), ymagn_out ( see table 18 ) contains y - axis magnetom eter data (m y in figure 17) , and zmagn_out ( see table 19 ) cont ains z - axis magnetometer data (m z in figure 17 ). table 20 illustrates the magnetometer data format with numerical examples. the lower four bits of each magne - tometer output data register (xmagn_out[3:0]) are not active at the maximum update rate of 51.2 sps. they become active when using smpl_prd[12:8] to average and decimate the data. the number of bits that become active is equal to the decimation setting number in smpl_prd[12:8]. for example, if smpl _prd[15:8] = 0x02, xmagn_out[15:2] are active an d xmagn_out[1:0] are inactive. table 17. x magn _out (base address = 0x 10 ), read o nly bits description [15 :0 ] x - axis magnetic field intensity data, 1.9 g auss twos complement, 7 lsb / m gauss , 0x0000 = 0 mgauss table 18. y magn _out (base address = 0x 12 ), read o nly bits description [15:0] y - axis magne tic field intensity data, 1.9 g auss twos complement, 7 lsb/mgauss, 0x0000 = 0 mgauss table 19. z magn _out (base address = 0x 14 ), read only bits description [15:0] z - axis magnetic field intensity data, 1.9 g auss twos complement, 7 lsb/mgauss, 0x0000 = 0 mgauss table 20 . magnetometer, twos complement format magnetic fie ld ( mg auss) decimal hex binary + 1 9 00 + 13,300 0x 33f4 0 011 0011 1 1 1 1 0100 +2 7 +2 0x0002 0000 0000 0000 0010 + 1 7 + 1 0x00 01 00 00 0000 000 0 000 1 0 0 0x0000 00 00 0000 0000 0000 +1 7 ? 1 0xffff 1111 1111 1111 1111 +2 7 ? 2 0xfffe 1111 1111 1111 111 0 ? 1 9 00 ? 13,300 0x cc0c 1100 11 00 0 0 0 0 1 100 barometric pressure baro_out ( see table 21) contains the barometric pressure data . table 22 provides several numeric al format examples for baro_out . table 21 . baro_out (base address = 0x16), read o nly bits description [1 5 :0] barometric pressure data, binary data format, 20 bar per lsb, 0x0000 = 0 mbar table 22 . pressure, binary, baro_out pressure decimal he x binary 1200 mbar 60,000 0x ea60 1110 1010 0110 0 0 0 0 1100 mbar 55,000 0x d6d8 1101 0110 1101 1000 1000 mbar 50,000 0x c350 1100 0011 0101 0000 0. 04 mbar 2 0x0002 00 00 0000 0000 0010 0.0 2 mbar 1 0x0001 00 00 0000 0000 0001 0 mbar 0 0x0000 00 00 0000 0000 0000 remote pressure sens ing th e adis16448 package offers a threaded hole (10 - 32) to support remote pressure sensing. figure 18 provides an example of a fitting , wh ich mates this hole to a barbed interface that enables a tight connection with rubber tubing (1/8). 09946-219 figure 18 . barb fitting for remote pressure sensing internal temperature the internal temperature measurement data loads into th e temp_out ( see table 23 ) register. table 24 illustrates the temperature data format. note that this temperature repre - sents an internal temperature reading, which will not precisely represent external conditions. the intended use of temp_out is to monitor relative changes in temperature. table 23 . temp_out (base address = 0x 1 8 ), read only bits description [ 15 :12] not used [11:0] t wos complement, 0. 0 7386 c/lsb, 31 c = 0x000 table 24 . temperature, twos complement format temperature ( c ) decimal hex binary + 105 + 100 2 3e a 0011 1110 10 10 + 85 + 731 2db 0010 1101 1011 + 31.1477 2 + 2 2 0000 0000 0010 + 31.07386 + 1 0 0000 0000 0001 + 31 0 0 0000 0000 0000 + 30 .92614 ? 1 fff 1111 1111 1111 + 30.8522 8 ? 2 ffe 1111 1111 1110 ? 40 ? 962 c3e 1100 0011 1110
adis16448 data sheet rev. b | page 14 of 24 s ystem f unctions global commands the glob_cmd register in table 25 provides trigger bits for software reset, flash memory management, and ca libration control . start each of these functions by writing a 1 to the assigned bit in glob_cmd . after completing the task, the bit automati - cally returns to 0 . for example, set glob_cmd[7] = 1 (din = 0 x be 80) to initiate a software reset . set glob_ cm d[3] = 1 (din = 0x be 0 8 ) to back up the user register contents in nonvolatile flash . this sequence includes loading the control registers with the data in their respective flash memory locations prior to producing new data. table 25 . glob_ cmd (base address = 0x 3e ), write o nly bits description (default = 0x0000) [15:8] not used 7 software reset [6: 4 ] not used 3 flash update 2 not used 1 factory calibration restore 0 gyroscope bias correction product identificati on the prod_id registe r in table 28 contains the binary equivalent of 16 , 448 . it provides a product specific variable for systems that need to track this in their system software . the lot_id1 and lot_id2 registers in table 26 and table 27 combine to provide a unique, 32- bit lot identification code . the serial_num register in table 29 contains a binary number that represents the serial number on the device label . the assig ned serial numbers in serial_num are lot specific. table 26 . lot_id1 (base address = 0x52), read only bits description [15:0] lot identification, binary code table 27 . lot_id2 (base address = 0x54), read on ly bits description [15:0] lot identification, binary code table 28 . prod_id (base address = 0x56), read only bits description (default = 0x 4040 ) [15:0] product identification = 0x 4040 table 29 . serial_nu m (base address = 0x58), read only bits description [15:1 2 ] reserved [1 1 :0] serial number, 1 to 4094 (0x ffe ) self - test function the msc _ ctrl register in table 30 provides a self - test function for the gyroscopes , accele r ometer s , magnetometers, and barometer s. note that the magnetometer results assume that the non - earth magnetic fields are low, in comparison to the earths magnetic field. this function allows the user to verify the mechanical integrity of each mems sensor. whe n enabled, the sel f test applies an electrostatic force to each internal sensor element, which causes them to move . the move ment in each element simulates its response to actual rotation/ acceleration and generates a predictable electrical response in the sensor outputs. set msc_ctrl[10] = 1 (din = 0xb504) to activ ate the internal self test routine, which compares the response to an expected range of responses and reports a pass/fail response to diag_stat[5]. if this is high, review diag_stat[15:10] to iden tify the failing sensor. table 30 . msc_ctrl (base address = 0x3 4 ), read/write bits description (default = 0x0006) [15:12] not used 11 check sum m emory test (cleared upon completion) 1 1 = enabled, 0 = disabled 10 internal self t est (cleared upon completion) 1 1 = enabled, 0 = disabled [9 :8 ] do not use, always set to 00 7 not used 6 point of percussion, see figure 22 1 = enabled, 0 = disabled [5:3] not used 2 dat a ready enable 1 = enabled, 0 = disabled 1 data ready polarity 1 = active high when data is valid 0 = active low when data is valid 0 data ready line select 1 = dio2, 0 = dio1 1 the bit is automatically reset to 0 after finishing the test.
data sheet adis16448 rev. b | page 15 of 24 status/error flags the diag_stat register in table 31 provides error flags for a number of functions . each flag uses 1 to indicate an error con - di tion and 0 to indicate a normal condition . reading this register provides access to the status of each flag and resets all of the bits to 0 for monitori ng future operation . if the error condition remains, the error flag return s to 1 at the conclusion of the next sample cycle . diag_stat[0] does not require a read of this register to return to 0. if the power supply voltage goes back into range, this flag clear s automatically . the spi communication error flag in diag_stat[3] indicates that the number of sclks in a spi sequence did not equal a multiple of 16 sclks. table 31 . diag_stat (base address = 0x 3c ), read only bits description (default = 0x0000) 15 z - axis accelerometer self - test failure 1 = fail, 0 = pass 14 y - axis accelerometer self - test failure 1 = fail, 0 = pass 13 x - axis accelerometer self - test failure 1 = fail, 0 = pass 12 z - axis gyroscope self - test failure 0 = pass 11 y - axis gyroscope self - test failure 1 = fail, 0 = pass 10 x - axis gyroscope self - test failure 1 = fail, 0 = pass 9 alarm 2 status 1 = active, 0 = inactive 8 alarm 1 status 1 = active, 0 = inactive 7 new data, xmagn_out/baro_out 6 flash test, checksum flag 1 = fail, 0 = pass 5 self - test diagnostic error flag 1 = fail, 0 = pass 4 sensor overrange 1 = overrange, 0 = normal 3 spi communication failure 1 = fail, 0 = pass 2 flash update failure 1 = fail, 0 = pass 1 barometer functional test 1 = fail, 0 = pass 0 magnetometer functional test 1 = fail, 0 = pass magnetometer/barometer new data indicator diag_stat[7] indicates that all four registers have new, unread data in them. this bit rises to 1 after the x magn_out and baro_out registers have new data updates. it lowers to zero after one of the registers are accessed using a spi - driven read command. this bit does not return to zero after reading diag_ stat. memory management the flash_cnt register in table 32 provides a 16 - bit counter that helps track the number of write cycles to the nonvolatile flash memory. the flash updates every time a manual flash update occurs. a manual flash update is initiated by the glob_cmd[3] bit and is p erformed at the completion of the glob_cmd[1:0] functions (see table 25). table 32 . flash_cnt (base address = 0x00), read only bits description [15:0] binary counter checksum test set msc_ctrl[11] = 1 (d in = 0xb 5 08) to perform a check - sum test of the internal program memory. this function takes a summation of the internal program memory and compares it with the original summation value for the same locations (from factory configuration). if the sum match es the correct value, diag_stat[6] is equal to 0 . if it does not match, diag_stat[6] is equal to 1. make sure that the power supply is within specification for the entire 20 ms that this function takes to complete.
adis16448 data sheet rev. b | page 16 of 24 input/output c onfiguration data ready indicator the data ready indicator provides a signal that indicates when the registers are updating, so that system proces sors can avoid data collision, a condition when internal register updates happen at the same time that an external processor request s it. the data ready signal has valid and invalid states. using the transition from invalid to valid to trigger an interrupt service routine provides the most time for data acquisition (before the next register update). see figure 4 and table 2 for specific timing information. msc_ ctrl[2:0] ( s ee table 30 ) provide control bits for enabling this function, selecting the polarity of the valid state and i/o line assignment (dio1, dio2 ). the factory default setting of msc_ctrl[2:0] = 110 (din = 0xb406) establishes dio1 as a data ready o utput line and assign s the valid state with a logic high (1) . s et msc_ctrl[2:0] = 100 (din = 0xb 4 04) to change the polarity of the data ready signal on d io1 for interrupt inputs that require negative logic inputs for activation. general - purpose i nput /o utput dio1, dio2, dio3, and dio 4 are configurable, general - pur pose input/output lines that serve multipl e purposes. the data ready controls in msc_ctrl [2:0 ] have the highest priority for configuring dio1 and dio2 . the alarm indicator controls in alm_ctrl[2:0 ] have the second highest priority for configuring dio1 and dio2 . the external clock control associated with smpl_prd [0] has the highest priority for di o4 configuration (see table 34 ). gpio_ctrl in table 33 has the lowest priority for configur ing dio1 , dio2 , and dio4 , and has absolute control over dio3. table 33 . gpio_ctrl (bas e address = 0x3 2 ), read/write bits description (default = 0x0000) [15:12] not used 11 general - purpose i/o line 4 (dio4) data level 10 general - purpose i/o line 3 (dio3) data level 9 general - purpose i/o line 2 (dio2) data level 8 general - purpose i/o lin e 1 (dio1) data level [7:4] not used 3 general - purpose i/o line 4 (dio4) direction control 1 = output, 0 = inpu t 2 general - purpose i/o line 3 (dio3) direction control 1 = output, 0 = input 1 general - purpose i/o line 2 (dio2) direction control 1 = output, 0 = input 0 general - purpose i/o line 1 (dio1) direction control 1 = output, 0 = input example i nput /o utput configuration for example, set gpio_ctrl[3:0] = 0100 (din = 0xb 2 04) to set dio3 as an output signal pin and dio1, dio2 , and dio4 as in put signal pins. set the output on dio3 to 1 by setting gpio_ctrl[10] = 1 (din = 0xb 3 04) . then, read gpio_ctrl [ 7:0 ] (din = 0x3 2 00) and mask off gpio_ctrl[9:8 ] and gpio_ctrl [11] to monitor the digital signal levels on dio4, dio2 , and dio1.
data sheet adis16448 rev. b | page 1 7 of 24 d igital proces sing configuration gyroscopes/accelerom eters figure 20 provides a diagram that describes all signal - processing components for the gyroscopes and accelerometers. t he internal sampling system produces new data in the xgyro_out and xaccl_out output data registers at a rate of 819.2 sps. the smpl_p rd register in table 34 provides two functional controls that affect sampling and register update rates . smpl_prd[12:8] provides a control for reducing the update rate, using an averaging filte r with a decimated output . these bits provide a binomial control that divides the data rate by a factor of 2 every time this number increases by 1 . for example, set smpl_prd[1 5 :8] = 0x04 (din = 0xb 7 0 4 ) to set the decimation fa ctor to 16 . this reduces the update rate to 51.2 sps and the bandwidth to ~ 25 hz . t he smpl_prd [12:8] setting affect s the update rate for the temp_out register (see table 23) as well. table 34 . smpl_prd (ba se address = 0x3 6 ), read/write bits description (default = 0x0001) [15:13] not used [12:8] d, decimation rate setting, binomial , see figure 20 [7:1] not used 0 clock 1 = internal sampling clock, 819.2 sps 0 = external sam pling clock input clock configur ation smpl_prd[0] (see table 34 ) provides a control for synchro - nizing the internal sampling to an external clock source. set smpl_prd[0] = 0 (din = 0xb600) and gpio_ctrl[3] = 0 (din = 0xb200) to e nable the external clock. see table 2 and figure 4 for timing information. digital filtering the sens_avg register in table 35 provides user controls for the low - pass filt er. this filter contains two cascaded averaging filters that provide a bartlett window, fir filter response (see figure 20 ). for example, set sens_avg[2:0] = 100 (din = 0xb 8 04) to set each stage to 16 taps. when used with the def ault sample rate of 819.2 sps and zero decimation (smpl_prd[1 5 :8] = 0x00 ) , this value reduces the sensor bandwidth to approximately 16 hz. 0 ?20 ?40 ?60 ?80 ?100 ?120 ?140 0.001 0.01 0.1 1 magnitude (db) frequenc y ( f / f s ) n = 2 n = 4 n = 16 n = 64 09946-018 figure 19 . bartlett window, fir filter frequency response (phase delay = n samples) dynami c range the sens_avg[10:8] bits provide three dynamic range settings for th e gyroscope s . the lower dynamic range settings ( 250 /sec and 50 0/sec) limit the minimum filter tap sizes to maintain resolution. for example, set sens_avg[10:8] = 010 (din = 0x b 9 02) for a measurement range of 50 0/sec. because this setting can influence the filter settings, program sens_avg[10:8] before programming sens_avg[2:0] if more filtering is required. table 35 . sens_avg (base address = 0x 3 8 ), re ad/write bits description (default = 0x0402) [15:11] not used [10:8] measurement range (sensitivity) selection 100 = 1 000 /sec (default condition) 010 = 50 0/sec, filter taps 4 (bits[2:0] 0x02) 001 = 250 /sec, filter taps 16 (bits[2:0] 0x04) [7:3] not used [2:0] filter s ize v ariable b number of taps in each stage; n b = 2 b see figure 19 for filter response mems sensor lo w - p ass fi l ter 330hz clock 819.2sps adc bartlett window fir fi l ter a verage/ decim a tion fi l ter externa l clock enabled b y smpl_prd[0] = 0 gyroscopes lo w - p ass, two-pole (404hz, 757hz) accelerometers lo w - p ass, single-pole (330hz) b = sens_ a vg[2:0] n b = 2 b n b = number of t aps (per s t age) d = smpl_prd[12:8] n d = 2 d n d = number of t aps n d x ( n ) n = 1 1 n b n b x ( n ) n = 1 1 n b n b x ( n ) n = 1 1 n d n d 09946-019 figure 20 . sampling and frequency response block diagram
adis16448 data sheet rev. b | page 18 of 24 magnetometer /barometer the magnetometer (xmagn_out) and barometer output registers (baro_out ) update at a rate of 51.2 sps. when using the external clock, these registers update at a rate of 1/16 th of the input clock frequency. the update rates for the magne - tometer a nd barometers do not change with the smpl_prd [1 5 :8] register settings, unless smpl_prd[1 5 :8] > 0x04. new - data indicators diag_stat [ 7 ] (see table 31 ) offers a new data bit for the magnetometer (xmagn_out) and barometer output reg isters (baro_out) registers . this bit rises to a 1, right after the xmagn_out and baro_out registers receive fresh data. it return s to 0 after one of the four registers experiences a read request. the seq_cnt register (see table 36) provides a counter function to help determine when there is new data in the magnetometer and barometer registers. when using the full sample rate ( smpl_prd[15:8] = 0x00 ), seq_cnt will start at a value of 16 and decrement every time the gyroscope data updates. when it reaches a value of 1, it will return to a value 16 after the next gyroscope update cycle. when seq_cnt equals 16, the magnetometer (xmagn_out) and barometer (baro_out) registers contain new data. the seq_cnt register can be useful during initialization to help synchronize read loops for new data in both magnetometer and barometer outputs. when beg inning a continuous read loop, read seq_cnt to determine the number of sample cycles that must pass, before the magnetometer and barometer regis ters update. table 36 . seq_cnt (base address = 0x3a) , read only bits description [15:11] dont care [6:0] binary counter: 16 to 1, when d = 0 counter r ange = 16/2 d C 1, when 1 d 4 see table 34 for more information on d
data sheet adis16448 rev. b | page 19 of 24 c alibration the mechanical structure and assembly process of the adis16448 provide excellent position and alignme nt stability for each sensor, even after subjected to temperature cycles, shock, vibration , and other environmental conditions . the factory calibration includes a dynamic characterization of each gyroscope and accelerometer over temperature and generates s ensor specific correction formulas . gyroscopes the xgyro_ off ( see table 37 ), ygyro_ off ( see table 38) , and zgyro_ off ( see table 39 ) registers provide user - programmable bias a dj ustment function for the x - , y - , and z - axis gyroscopes, respec tively. figure 21 illustrates that the y contain bias correction factors that adjust to the sensor data immediately before it loads into the output register. xgyro_off xaccl_off mems sensor adc f ac t o r y calibr a tion and fi l tering xgyro_out xaccl_out 09946-020 figu re 21 . user calibration, gyroscopes , and accelerometers gyroscope bias error estimation any system l evel calibration function must start with an estimate of the bias errors, which typically comes from a sample of gyro - scope o utput data, when the device is not in motion. the sample size of data depends on the accuracy goals . figure 7 provides a trade - off relationship between averaging time and the expected accuracy of a bias measurement. vibration, thermal gradients, and power supply instability can influence the accuracy of this process. table 37 . xgyro_off (base address = 0x1 a ), read/write bits description (default = 0x0000) [15 :0] x - axis, gyroscope offset correction factor, twos complement, 0.01 /sec /lsb , 0 /sec = 0x0000 table 38 . ygyro_off (base address = 0x 1c ), read/write bits description (default = 0x0000) [15:0] y - axis, gyroscope offset correction factor, twos complement, 0.01/sec/lsb, 0 /sec = 0x0 000 table 39 . zgyro_off (base address = 0x 1e ), read/write bits description (default = 0x0000) [15:0] z - axis, gyroscope offset correction factor, twos complement, 0.01/sec/lsb, 0 /sec = 0x0000 gyroscope bias correction factors w hen the bias estimate is complete, multiply the estimate by ? 1 to change its polarity, convert it into digital format for the offset correct ion registers ( see table 37, table 38 , and table 39 ) , and write the correction factors to the correction registers. for example, lower the x - axis bias by 10 lsb (0.1 /sec) by setting xgyro_off = 0x f ff6 (din = 0x9 b f f, 0 x 9 a f6 ). single command bias correction glob_cmd[0] ( see table 25) loads the xgyro_off registers with the values that are the opposite of the values that are in xgyro_o ut, at the time of initiation. use this command, together with the decimation filter (smpl_prd[12:8], see tabl e 34) , to automatically average the gyroscope data and improve the accuracy of this function , as follows: 1. set sens_avg[10:8] = 001 (din = 0xb 9 01) to optimize the xgyro_out sensitivity to 0.01 / sec/lsb. 2. s et smpl_prd[1 2 :8] = 0x10 (din = 0x b 7 10) to set the decimation rate to 65,536 (2 16 ), which provides an averaging time of 80 seconds (65 , 536 819.2 sps) . 3. wait for 80 seconds while keeping the device motionless. 4. s et glob_cmd[0] = 1 (din = 0x b e 01) and wait for the t ime it takes to perform the flas h memory bac k up . accelerometers the xaccl_o ff ( see table 40 ), yac cl _o ff ( see table 41 ), and zaccl_o ff ( see table 42 ) registers provide user programmable bias a djustment function for the x - , y - , and z - axis accelerometers, respectively. these registers adjust the accelerometer data in the same manner as xgyro_off in figure 21. table 40 . xaccl_off (base address = 0x2 0 ), read/write bits descr iption (default = 0x0000) [1 5 :0] x - axis, accele rometer offset correction factor, t wos complement, 1/ 1200 g /lsb , 0 g = 0x0000 table 41 . yaccl_off (base address = 0x2 2 ), read/write bits description (default = 0x0000) [15:14] not u sed [13:0] y - axis, accelerometer offset correction facto r, twos complement, 1/1200 g /lsb, 0 g = 0x0000 table 42. z accl_off (base address = 0x2 4 ), read/write bits description (default = 0x0000) [15:14] not used [13:0] z - axis, ac celerometer offset correction factor , twos complement, 1/1200 g /lsb, 0 g = 0x0000 accelerometer bias error estimation under static conditions, orient each accelerometer in positions where the response to gravity is predictable. a common approach to this is to measure the response of each accelerom eter when they are oriented in peak response positions, that is, where 1 g is the idea l measurement position . next , average the +1 g and ? 1 g accelerometer measurements together to estimate the residual bias error. using more points in the rotation can improve the accuracy of the response.
adis16448 data sheet rev. b | page 20 of 24 accelerometer bias correction factors when the bias estimate is complete, multiply the estimate by ? 1 to change its polarity, convert it to the digital format for the offset correction registers ( see table 40, table 41 or table 42) and write the correction factors to the corr ection registers. for example, lower the x - ax is bias by 1 2 lsb ( 10 m g ) by setting xaccl_off = 0x fff4 (din = 0x a 1 ff , 0x a 0 f 4 ). point of percussion alignment set msc_ctrl[6] = 1 (din = 0xb 4 46) to enable this feature and maintain the factory default settings f or dio1. this feature performs a point of percussion translation to the point identified in figure 22 . see table 30 for more information on msc_ctrl. 09946- 1 19 origin alignment reference point see msc_ctrl[6]. figure 22 . point of percu ssion physical reference magnetometer calibra tion the adis16448 provides registers that contribute to both hard iron and soft iron correction factors, as shown in fi gure 23. adc xmagn_out magnetic sensor f ac t o r y calibr a tion and fi l tering 1 + xmagn_sic xmagn_hic 09946-022 figure 23 . hard iron and soft iron factor correction hard iron correction the xmagn _hic ( see table 43 ), ymagn _hic ( see table 44) , and zmagn _hic ( see table 45 ) registers provide the user programm able bias adjustment function for the x - , y - , and z - axis magnetometers, re spectively. hard iron effects result in an offset of the magneto meter response. table 43 . xmagn_hi c (base address = 0x26 ), read/write bits description (default = 0x 0 0 00) [1 5 :0] x - axis hard iron correction factor , twos complement, 7 lsb / m gauss, 0x0000 = 0 table 44 . ymagn_hi c (base address = 0x28 ), read/write bits description (de fault = 0x 0 0 00) [1 5 :0] y - axis hard iron correction factor , twos complement, 7 l sb/mgauss, 0x0000 = 0 table 45 . zmagn_hi c (base address = 0x2a ), read/write bits description (default = 0x 0 0 00) [1 5 :0] z - axis har d iron correction fac tor , twos complement, 7 lsb/mgauss, 0x0000 = 0 mgauss hard iron factors when the hard iron error estimation is complete , take the following steps: 1. m ultiply the estimate by ? 1 to change its polarity . 2. c onvert it into digital format for the hard iron correct ion registers ( see table 43) . 3. w rite the correction factors to the registers. for example, lower the x - axis bias by 10 lsb ( ~ 1.429 m g auss) by setting xmagn _hic = 0x f ff6 (din = 0x a 7 f f, 0 x a 6 f6 ) soft iron effects the xmagn _sic ( see table 46 ), ymagn _sic ( see table 47) , and zmagn _sic ( see table 48 ) registers provide a n adjust - ment variable for the magnetometer sensitivity adjustment in each magnetometer re sponse to simplify the process of performing a system level soft iron correction. table 46 . xmagn _sic (base address = 0x 2c ), read/write bits description (default = 0x 8 000) [1 5 :0] x - axis soft iron correction factor , twos complement format , 1 lsb = 100%/32 , 767 0x 7 fff = 1 00% increase (2 ) 0x8000 = 100% decrease (0 ) table 47 . ymagn_si c (base address = 0x 2e ), read/write bits description (default = 0x 8 000) [15:0] y - axis soft iron correction factor, twos comp lement format, 1 lsb = 100%/32 , 767 0x7fff = 100% increase (2) 0x8000 = 100% decrease (0) table 48 . zmagn _sic (base address = 0x3 0 ), read/write bits description (default = 0x 8 000) [15:0] z - axis soft iron correction factor, two s complement format, 1 lsb = 100%/32 , 767 0x7fff = 100% increase (2) 0x8000 = 100% decrease (0) flash updates when using the user calibration registers to optimize system level accuracy, set glob_cmd[3] = 1 (din = 0x be 04) to save these settings in non v olatile flash memory. be sure to consider the endurance rating of the flash memory when determining how often to update the user correction factors in the flash memory. restoring factory ca libration set glob_cmd[1] = 1 (din = 0x be 02) to execute the facto ry calibration restore function , which resets the gyroscope and accel - erometer offset register s to 0x 0000 and all sensor data to 0 . then, it automatically updates the flash memory and re starts sampling and processing data . see table 25 for information on glob_cmd.
data sheet adis16448 rev. b | page 21 of 24 a larms alarm 1 and alarm 2 provide two independent alarms with programmable levels, polarity , and data sources. static alarm use the static alarms setting compares the data source selection (alm_ctrl[15:8]) with the va lues in the alm_magx registers listed in table 49 and table 50 , using alm_magx[15] to deter - mine the trigger polarity . the data format in these registers matches the format of the data selection in alm_ ctrl[15:8]. see table 54, alarm 1, for a static alarm configuration example. table 49 . alm_mag1 (base address = 0x4 0 ), read/write bits description (default = 0x0000) [1 5 :0] threshold setting; matches for format of alm_ctrl[11:8] output register selection table 50 . alm_mag2 (base address = 0x4 2 ), read/write bits description (default = 0x0000) [1 5 :0] threshold setting; matches for format of alm_ctrl[15:12] output register selection dynamic alarm use the dynamic alarm setting monitors the data selection for a rate - of - change compariso n . the rate - of - change comparison is represented by the magnitude in the alm_magx registers over the time represented by the number - of - samples setting in the alm_smplx registers, located in table 51 . see table 54 , alarm 2, for a dynamic alarm configuration example. table 51 . alm_smpl1 (base address = 0x 44 ), read/write bits descrip tion (default = 0x0000) [15:8] not used [7:0] binary, number of samples (both 0x00 and 0x01 = 1) table 52 . alm_smpl 2 (base address = 0x4 6 ), read/write bits description (default = 0x0000) [15:8] not used [7:0] binary, number of samples (both 0x00 and 0x01 = 1) alarm r eporting the diag_stat[9 :8 ] bits provide error flags that indicate an alarm condition. the alm_ctrl[2:0] bits provide controls for a hardware indicator using dio1 or dio2. table 53 . alm_ ctrl (base address = 0x4 8 ), read/write bits description (default = 0x0000) [15:12] alarm 2 data source selection 0000 = disable 0001 = xgyro_out 0010 = y gyro_out 001 1 = z gyro_out 0 100 = xaccl_out 010 1 = y accl_out 0110 = z accl_out 011 1 = xm agn_out 1001 = y magn_out 1010 = z magn_out 1011 = baro _out 1100 = temp_out [11:8] alarm 1 data source selection (same as alarm 2) 7 alarm 2, dynamic/static (1 = dynamic, 0 = static) 6 alarm 1, dynamic/static (1 = dynamic, 0 = static) 5 alarm 2, polarity (1 = greater than alm_mag2) 4 alarm 1, polarity (1 = greater than alm_mag1) 3 data source filtering (1 = filtered, 0 = unfiltered) 2 alarm indicator (1 = enabled, 0 = disabled) 1 alarm indicator active polarity (1 = high, 0 = low) 0 alarm out put line select (1 = dio2, 0 = dio1) alarm example table 54 offers an example that configures alarm 1 to trigger when filtered zaccl_out data drops below 0.7 g and alarm 2 to trigger when filtered zgyro_out data changes by more than 5 0/sec over a 100 ms period , or 5 00/sec 2 . the filter setting helps reduce false triggers from noise and refine s the accuracy of the trigger poin ts . the alm_smpl2 setting of 8 2 samples provides a comparison period that is approximately equal to 100 ms for an internal sample rate of 819.2 sps . table 54 . alarm configuration example din description 0x cd 36, alm_ctrl = 0x 36af 0x cc af alarm 2: dynamic, - zgyro_out ( - time, alm_smpl2) > alm_mag2 alarm 1 : static, zaccl_out < alm_mag1, f iltered data di o2 output indicator, positive polarity 0x c7 0 4 , 0x c6 e 2 alm_mag 2 = 0x 0 4e2 = 1, 250 lsb = 5 0/ sec 0x c5 0 3 , 0x c4 48 alm_mag 1 = 0x0 348 = 840 lsb = + 0. 7 g 0x c8 6 6 alm_smpl2[7:0] = 0x 52 = 82 samples 82 samples 819.2 sps = ~100 ms
adis16448 data sheet rev. b | page 22 of 24 applications information power supply considerations the power supply must be within 3.15 v and 3.45 v for normal operation and optimal performance. during start up, the internal power conversion system starts drawing current when vdd reaches 1.6 v. the internal processor begins initializing when vdd is equal to 2.35 v. after the processor starts, vdd must reach 2.7 v within 128 ms. also, make sure that the power supply drops below 1.6 v to shut the device down. figure 9 shows a 10 f capacitor on the power supply. using this capacitor supports optimal noise performance in the sensors. adis16448/pcbz the adis16448/pcbz includes one adis16448amlz , one interface pcb, and one flexible connector/cable. this particular flexible cable mates the adis16448amlz to any system that uses the adis1636x, adis16375 , adis16385 , adis1640x, or adis1648x imu products, which all use a 24-pin interface, rather than the 20-pin interface that the adis16448 uses. this combination of components enables quicker installation for prototype evaluation and algorithm development. figure 24 provides a mechanical design example for using these three components in a system. adis16448bmlz interface pcb 33.40mm 23.75mm 20.15mm 30.10mm 10.07mm 15.05mm j1 1 11 1 11 12 2 12 2 j2 notes 1. use four m2 machine screws to attach the adis16448. 2. use four m3 machine screws to attach the interface pcb. flexible connector/cable 15m m to 45mm 09946-021 figure 24. physical diagram for mounting the adis16448/pcbz figure 25 provides the pin assignments for the interface board. 1 2 3 4 5 6 7 8 9 10 11 12 dnc dnc dnc dnc dio2 dnc dnc dio1 dio4 dio3 gnd j2 gnd 2 4 6 8 10 1 3 5 7 9 11 12 rst cs gnd gnd vdd gnd vdd vdd din dout sclk j1 dnc 09946-122 figure 25. j1/j2 pin assignments for interface pcb installation the following steps provide an example installation process for using these three components: ? drill and tap m2 and m3 holes in the system frame, according to the locations in figure 24. ? install the adis16448 using m2 machine screws. use a mounting torque of 25 inch-ounces. ? install the interface pcb using m3 machine screws. ? connect j1 on the interface flex to the adis16448amlz connector. ? connect j2 on the interface flex to j3 on the interface pcb. note that j2 (interface flex) has 20 pins and j3 (interface pcb) has 24 pins. make sure that pin 1 on j2 (interface flex) connects to pin 20 on j3 (interface pcb). j3 has a pin 1 indicator to help guide this connection. ? use j1 and j2 on the interface pcb to make the electrical connection with the system supply and embedded pro- cessor, using 12-pin, 1 mm ribbon cables. the following parts may be useful in building this type of cable: 3m part number 152212-0100-gb (ribbon crimp connector) and 3m part number 3625/12 (ribbon cable). the c1/c2 pads on the interface pcb do not have capacitors on them, but these pads can support the suggested power supply capacitor of 10 f (see figure 9). pc-based evaluation tools the eval-adis supports pc-based evaluation of the adis16448 . go to www.analog.com/eval-adis , to down- load the user guide ( ug-287 ) and software (imu evaluation).
data sheet adis16448 rev. b | page 23 of 24 outline dimensions 03-14-2013-d top view side view 33.40 bsc 30.10 bsc 19.55 bsc 12.50 bsc 0.66 bsc 2.00 bsc 2.30 bsc (2 plcs) 2.30 bsc (2 plcs) 1.00 bsc 2.00 bsc 20.150 bsc 29.200 bsc 6.70 bsc 1 0 - 3 2 t h r e a d e d h o l e 7.89 7.63 7.37 4.70 4.50 4.30 2.60 2.40 dia. 2.20 38.08 37.70 37.32 24.53 24.15 23.77 end view 2.84 bsc (pin height) 5.18 bsc (pcb to connector) 7.57 bsc 10.23 bsc 1.00 bsc pitch 11.10 10.80 10.50 2.96 2.70 2.44 figure 26. 20-lead module with connector interface (ml-20-2) dimensions shown in millimeters ordering guide model 1 temperature range package description package option adis16448amlz ?40c to +85c 20-lead module with connector interface ml-20-2 adis16448/pcbz interface pcb 1 z = rohs compliant part.
adis16448 data sheet rev. b | page 24 of 24 notes ? 2012 C 2013 analog devices, inc. all rights reserved. trademarks and registered trademarks are the property of their r espective owners. d09946 - 0 - 7/13(b)

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