Data Sheet - Silicon Sensing Systems
Contents
1. during over range Pin sce eae e o Scale Factor Error per as we ee OO O E Over operating Bias s temperature range Bias drift with time s temp rature As measured using the Anoe Random Walk All lt 0 40 Allan Variance method Vhr 3600 1800 3600 Bias Repeatability hr EJ Over operating Gyro Bandwidth Hz All lt 10 85 gt 150 oom User programmable ae Wide band noise at Noise s rms All po 0 10 0 15 100E haida dih 3 3g rms stimulus 20HZz to 2 000HZ Bias Repeatability Ni BiaSwarmup BiaStoto BiaSageing BiaStemperature Gyro Cross Coupling VRE s rms g 0 006 Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 4 DMU10 00 0100 132 Rev 4 D M Ut 0 Technical Datasheet S LICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 3 Performance Continued Linear Acceleration X Y Z during over range w e e o Scale Factor Error of ee oe Scale Factor Non Linearity Maximum error from best straight K 150 00 50 00 150 00 Over operating Bias mo temperature range 20 00 10 00 20 00 T ie os At constant Bias drift with time mg Emo rae Bias Instability mg All lt 0 05 As mea2. DOO Regulator Voltage BIT Function Scheduler_Slot_Period_Extended This flag will be set if the DMU10 software 7 9 3 System Error Indication BIT Flags scheduler could not complete its allocated tasks DO1 A Se Hie ares These flags indicate which message items have faults EE cuennas NenUe aca wore Ka aaa associated with them This will normally be caused by a hardware fault that caused a timeout When this flag is set the a DMU10 will output data at a decreased rate BIT No System Error Indication BIT Flags Output Message Missed DOO o Hee a Error X axis Rate for standard This flag will be set if the previous output message 9 i was missed This will occur if the DMU10 was 50 Message Item 02 Error X axis acceleration for D02 unable to output a serial port message because standard message format the previous message was still being sent This will normally be caused by incompatible Message or p02 Message Item 03 Error Y axis Rate for standard Baud Rate selection message format Internal_Processor_ Error p03 Message Item 04 Error Y axis acceleration for This flag will be set if the software timed out standard message format while accessing hardware internal to the DOS microprocessor A D SPI The output items D04 Message nae Error Z axis Rate for standard affected by this failure will be marked in the Item message formal Error Indication table ae Message Item 06 Error Auxillary input for Orion Operation Error standard message format
3. Factor Error Temperature C Temperature C Figure 5 5 Accelerometer Bias Figure 5 6 Accelerometer Scale Factor Error All Axes NL o 0 02 Misalignment Error 0 04 0 06 0 08 i 10 5 0 5 10 Temperature C Applied Acceleration g Figure 5 7 Accelerometer Cross Coupling Figure 5 8 Accelerometer Non Linearity Error Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 8 DMU10 00 0100 132 Rev 4 D M U1 0 Technical Datasheet SILICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 5 2 Typical Performance Characteristics Calibrated DMU10 21 and DMU10 22 0 1 Bias dps Scale Factor Error 0 1 Temperature C Temperature C Figure 5 9 Gyroscope Bias Figure 5 10 Gyroscope Scale Factor Error 0 5 Misalignment Error o Distribution of Population 0 5 4 60 40 20 0 20 40 60 80 100 a 0 025 0 05 0 075 0 4 0 125 0 15 0 475 0 2 0 225 0 25 0 275 0 3 Temperature C Max Non Linearity Error of Full Scale Figure 5 11 Gyroscope Cross Coupling Figure 5 12 Gyroscope Non Linearity Distribution Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Produ
4. M U1 O echnical Datasheet Six Degrees of Freedom Precision MEMS Inertial Measurement Unit SILICON SENSING www siliconsensing com 11 DMU10 MEMS Sensor Internal Construction and Theory of Operation Construction The DMU10 uses three MEMS rate and acceleration Combi Sensors providing three gyroscopes and six accelerometers Each Combi Sensor comprises six main components silicon MEMS Single Axis Angular Rate Sensor Silicon On Glass SOG Dual Axis MEMS Accelerometer Silicon Pedestal ASIC Package Base and Lid The MEMS Sensors ASIC and Pedestal are housed in a hermetically sealed package cavity with a nitrogen back filled partial vacuum this has particular advantages over sensors supplied in plastic packages which have Moisture Sensitivity Level limitations An exploded drawing of a Combi Sensor showing the main components is given in Figure 11 1 below Vacuum Cavity Seal Ring Bond Wires C G 18542 Figure 11 1 Combi Sensor Main Components it i oe cx Figure 11 2 Combi Sensor Lid Removed Silicon MEMS Ring Sensor Gyro The 3mm diameter by 65um thick silicon MEMS ring is fabricated by Silicon Sensing using a DRIE Deep Reactive lon Etch bulk silicon process The annular ring is Supported in free space by eight pairs of dog leg shaped symmetrical spokes which radiate from a central 1mm diameter solid hub The bulk silicon etch process and unique patented
5. This flag will be set if there are any Orion Operation Message Item 07 Error Temperature for D04 Flags set in any of the three 32 BIT Orion BIT flag DO6 standard message format arrays The output items affected by this failure will be marked in the Error Indication table D07 Message Item 08 Error X delta theta for standard message format Output_Value_Out_Of_Range Set when an output value has been clamped p08 Message Item 09 Error X delta velocity for because it is out of range The output items standard message format DOS affected by this failure will be marked in the Error Indication table p09 Message Item 10 Error Y delta theta for standard Max Rate 3057s message format Max Acceleration 10 01g D010 Message Item 11 Error Y delta velocity for Plausibility Error standard message format Set when the system has determined that a Message Item 12 Error Z delta theta for standard sampled sensor value is implausible The output D011 message format items affected by this failure will be marked in the DOG Error Indication table D012 Message Item 13 Error Z delta velocity for standard message format This currently only applies to accelerometer sensors which have corresponding sensors in the D013 Message Item 14 Error same sense axis DO7 Spare D014 Message Item 15 Error DOS Spare D015 Message Item 16 Error DOQ Spare avec Table 7 5 System Error Indication BIT Flags Copyright 2015 Silicon Sensing Systems Limited Al
6. Vels e Cycle 5 Sample Sensors 2nd order Filter Transmit Message The message is transmitted after the Sync Pulse associated with Cycle 5 has returned LOW The inertial data included in the message is generated when the Sync Pulse associated with Cycle 3 was HIGH This enables the external equipment to synchronise with the time when the Inertial Data was valid Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 15 D M U1 0 Technical Datasheet SILICON SENSING Six Degrees of Freedom Precision J www siliconsensing com MEMS Inertial Measurement Unit ims SYNC Output gt Yr pAp AN Sensor logging 0 19ms Sensor logging filtering and temperature averaging 0 44ms a 0 31ms Gyro and Temperature Gyro and Temperature Sensor acceleration Voltage amp BIT acceleration Voltage amp BIT Logging data data data data logging logging logging logging Application Temperature Application Temperature of 2nd order running of 2nd order running filter 100Hz average filter 100Hz average default default C G 18738 Figure 7 3 Relationship between SYNC and Sensor Logging Serial TX of 34 words at 460 800 baud 1 623ms every 5ms using DMA Sensor error calculation Sensor compensation TX End 0 05ms every 5ms
7. market the DMU10 Combi Sensor has a specially developed seam weld process which eliminates the potential for internal weld spatter Inferior designs can cause dislodged weld spatter which affects gyro reliability due to interference with the vibratory MEMS element especially where the MEMS structure has small gaps unlike Combi Sensor with its large gaps as described above Theory of Operation Gyro The rate sensor is a solid state device and thus has no moving parts other than the deflection of the ring itself It detects the magnitude and direction of angular velocity by using the coriolis force effect As the gyro is rotated coriolis forces acting on the silicon ring cause radial movement at the ring perimeter There are eight actuators transducers distributed evenly around the perimeter of the silicon MEMS ring Located about its primary axes 0 and 90 are a single pair of primary drive actuators and a single pair of primary pick off transducers Located about its secondary axes 45 and 135 are two pairs of secondary pick off transducers The primary drive actuators and primary pick off transducers act together in a closed loop system to excite and control the ring primary operating vibration amplitude and frequency 22kHz Secondary pick off transducers detect radial movement at the secondary axes the magnitude of which is proportional to the angular speed of rotation and f
8. s rt hz 0 10 20 30 40 50 60 70 80 90 100 10 10 10 10 Frequency in Hz Frequency in Hz Figure 5 19 Gyroscope Cumulative Noise Figure 5 20 Gyroscope Spectral Noise Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 11 D M U1 0 Technical Datasheet S LICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com Typical Performance Characteristics Uncalibrated and Calibrated Noise dps rms Allan Variance in mg one sigma Correlation Time seconds Temperature C Figure 5 21 Gyroscope Noise Figure 5 22 Accelerometer Allan Variance over Temperature g Bias Stability in mg one sigma Cumulative Noise in mg rms gae 10 10 ie 40 10 10 0 10 20 30 40 50 60 70 80 90 100 Correlation Time seconds Frequency in Hz Figure 5 23 Accelerometer Stability Figure 5 24 Accelerometer Cumulative Noise Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 12 DMU10 00 0100 132 Rev 4 D M U1 0 Technical Datasheet SILICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Uni
9. 0 03ms every 5ms TX Start Message processing 200Hz 5ms 1 000Hz 1ms Sensor logging filtering and temperature averaging C G 18739 Figure 7 4 Relationship between Sensor Logging Compensation and Transmitted Output Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 16 DMU10 00 0100 132 Rev 4 D M U1 0 Technical Datasheet S LICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 7 8 Operational Message Definitions 7 9 System BIT Flags The data output message has the content and sequence as shown in the table below 7 9 1 System Startup BIT Flags These flags indicate errors detected during DMU10 Item Word Data Item Value Unit ne re Initialisation Once set these flags will not be cleared 0 0 Header 16 Bit Ox55AA for the whole of the power cycle 16 Bit O to 65535 BIT No System Startup BIT Flags 1 1 Message Count n decimal Code_Checksum_Fail 2 9 3 Axis X Rate 32 Bit single Precision DOO Set if the DMU10 code checksum does not FP s match If this flag is set correct operation of the Axis X 32 Bit Single Precision ene GANMOL DO guaranipaa 3 4 5 Acceleration FP 9 NVM _ Coefficient_Checksum Fail 32 Bit Single Precision Set if the DMU
10. 10 NVM coefficient checksum 4 6 7 Axis Y Rate ENS oe does not match If this flag is set correct Axis Y 32 Bit Single Precision operation of the DMU10 cannot be guaranteed 5 8 9 Acceleration FP 9 a Orion_Startup_Error 6 10 11 Axis Z Rate 32 Bit Single Precision This flag will be set if there were any Orion Startup FP s Flags set in any of the three 32 BIT es Orion BIT flag arrays The output items affected P Axis Z 32 Bit Single Precision Snag 9 i cre a ae Aeeaicaion FP o y this failure will be marked in the Item Error Indication table 32 Bit Single Precision 8 14 15 Aux Input Voltage Pics WVOMS Internal_Processor_Error Average IMU 32 Bit Single Precision DO3 Set if there was an error accessing hardware 9 16 17 Temperature FP C internal to the microprocessor 40 18 19 Axis X Delta 32 Bit Single Precision Theta FP Invalid_NVM_Coefficient Set if an NVM coefficient value is invalid If i Axis X Delta 32 Bit Single Precision this affects an operational output item the 11 20 21 D04 ar Vel FP m s corresponding item will be marked in the Item Error Axis Y Delta 32 Bit Single Precision Indication table and this should help to identify 12 22 23 o which coefficient is invalid Theta FP e Secs Axis Y Delta 32 Bit Single Precision ee PPA Vel FP m s DOG Spare i it Si isi DO7 Spare 14 26 27 Axis Z Delta 32 Bit S
11. D M U1 0 echnical Datasheet Six Degrees of Freedom Precision MEMS Inertial Measurement Unit SILICON SENSING www siliconsensing com DMU10 01 21 OEM Features e High performance six degrees of freedom 6 DOF MEMS IMU e sensor inputs Angular rate x3 Linear acceleration x3 Temperature e Dynamic Range 300 s and 10g e Bias instability lt 10 hr and 0 05mg e Random Walk lt 0 4 vhr and 0 05m s e Small 45 x 26 x 16mm e User programmable bandwidth e 3 2 to 5 25V Supply e Wide operating temperature range 40 C to 85 C e RS 422 Interface e Optional Configurations Uncalibrated and thermally calibrated OEM and Module e ROHS compliant Applications e Machine control e Antenna and Platform Stabilisation e Precision Agriculture e Autonomous Vehicles and ROVs e Attitude Measurement Systems e Personal Navigation e GPS Aiding DMU10 02 22 Module 1 General Description DMU10 is a 6 DOF Precision MEMS Inertial Measurement Unit from Silicon Sensing Systems It provides three axes of angular rate and linear acceleration and temperature The output message includes message counter built in test results delta theta and delta velocity information Data is output on an industry standard RS422 interface for ease of integration DMU10 is engineered using Silicon Sensing s own unique MEMS VSG65 ring gyroscope and capacitive accelerometer technologies to provide benchmark performance s
12. Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com Notes Silicon Sensing Systems Limited Silicon Sensing Systems Japan Limited Specification subject to change without notice Clittaford Road Southway 1 10 Fuso Cho Copyright 2015 Plymouth Devon Amagasaki Silicon Sensing Systems Limited PL6 6DE United Kingdom Hyogo 6600891 Japan eee T 44 0 1752 723330 T 81 0 6 6489 5868 Ae eae F 44 0 1752 723331 F 81 0 6 6489 5919 E sales siliconsensing com E SsSsj spp co jp DMU10 00 0100 132 Rev 4 W siliconsensing com W siliconsensing com DCR No 710009189 Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 28 DMU10 00 0100 132 Rev 4
13. IMU part number DMU10 21 0100 e MEV RS485i to USB converter e CD containing the MEV drivers e USB memory stick containing the data logging software e Interface cables e User manual 8 1 2 System Requirements The DMU10 Evaluation Kit requires a PC with a USB port The requirements for the PC are as follows e Microsoft Windows XP SP3 or greater Vista Windows 7 or Windows 8 Operating Systems The software has not been tested on any other Operating System and therefore correct functionality cannot be guaranteed e Minimum of 500Mb of RAM e 500Mb of free hard drive space plus space for logged data typical data rate 5O0kbit s e High power or self powered USB 2 0 Port 9 Part Markings DMU10 is supplied with an adhesive label attached The label displays readable DMU10 part and part identification numbers The part identification number is a numeric code WWYYXXXX C or CC where WW Manufacturing week number YY Manufacturing year number XXXX Serial number C CC Revision A 4x4 data matrix barcode containing the part identification number is also displayed on the label Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 20 DMU10 00 0100 132 Rev 4 D M U1 O echnical Datasheet Six Degrees of Freedom Precision MEMS
14. Inertial Measurement Unit SILICON SENSING www siliconsensing com 10 Installation Details Figures 10 1 and 10 2 show the installation drawing for the DMU10 the OEM and Module versions respectively The DMU10 OEM is supplied as a PCBA It is recommended that the PCBA is mounted on spacers or pillars using the four mounting holes provided The holes are clearance holes for use with M2 0 screws During calibration alignment is achieved using external reference dowels on two sides of the PCBA These two sides therefore form the datum for alignment purposes The DMU10 Module is designed for 3 point mounting using M2 5 screws During calibration alignment is achieved using two external reference dowel holes on the base of the DMU10 The dowel holes are designed to be used with two 2mm in accordance with BS EN ISO 8734 or BS EN ISO 2338 dowel pins provided by the host The DMU10 mounting screw torque settings will be dependent on the host application it will for example vary depending on the specification of the screw the material of the host structure and whether a locking compound is used When securing a DMU10 OEM unit to the host system using steel M2 screws and a thread locking compound the suggested torque setting is 0 1Nm for securing to an aluminium host structure When securing a DMU10 Module unit to the host system using steel M2 5 screws and a thread locking compound the suggested torque setting is 0 2Nm for s
15. Surface Mount Technology SOG Silicon On Glass SD Secondary Drive oP Secondary Pick Off T B A To Be Advised PBD To Be Determined V Volts 7 Interface Physical and electrical inter connect and R8422 message information 7 1 Electrical Interface 3 2 to 5 25V PL1_2 PL1_3 PL1_4 SYSTEM Tx Hi HOST PL1_10 DMU10 6V or 3 3V SYSTEM PL1_5 PL1_6 PL1_8 OV PL1_1 A These connections are optional and can be left not connected z C G 18711 Figure 7 1 Required Connections for RS422 Communications with DMU10 7 2 Physical Interface 10 05 Part No HARWIN G125 MV11205L1 C G 18720 Figure 7 2 Male Connector DMU10 Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 14 DMU10 00 0100 132 Rev 4 D M U1 O echnical Datasheet Six Degrees of Freedom Precision MEMS Inertial Measurement Unit SILICON SENSING www siliconsensing com 7 3 Connector Specification The physical connector for the DMU10 is from the Gecko family of connectors produced by Harwin The part number for the board connector is G125 MV11205L1 The female mating connector used to interface with this connector is part number G125 204 12 96 LO with crimps G125 0010008 for 26 AWG wires or G125 0010005 f
16. cts joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 9 D M U1 0 Technical Datasheet S LICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com Typical Performance Characteristics Calibrated DMU10 21 and DMU10 22 ai a Temperature C Bias mg Scale Factor Error 4 Figure 5 13 Accelerometer Bias Figure 5 14 Accelerometer Scale Factor Error 0 08 0 06 0 04 0 02 All Axes NL o 0 02 Misalignment Error 0 04 0 06 0 08 a p EESE E 5 Applied Acceleration g Figure 5 15 Accelerometer Cross Coupling Figure 5 16 Accelerometer Non Linearity Error Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 10 DMU10 00 0100 132 Rev 4 D M U1 0 Technical Datasheet S LICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 5 3 Typical Performance Characteristics Uncalibrated and Calibrated Allan Variance in deg h one sigma In Run Stability in deg h one sigma Correlation Time seconds Correlation Time seconds Figure 5 17 Gyroscope Allan Variance Figure 5 18 Gyroscope Stability Cumulative Noise in deg s rms Gyro output in deg
17. d to top and bottom glass substrates to form a hermetically sealed Silicon on Glass SOG wafer sub assembly The same DRIE bulk silicon process as used to create the gyro in is used to create two orthogonal finger like spring seismic proof mass structures each measuring 1 8mm square and with a resonant frequency of 2 9kHz Figure 11 3 shows a schematic cross section through the SOG wafer Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 23 D M U1 O echnical Datasheet Six Degrees of Freedom Precision MEMS Inertial Measurement Unit SILICON SENSING www siliconsensing com Capacitive drive and pick off signals are transmitted by wire bond interconnections in through glass vias between the metallised transducer plates on the MEMS proof mass and the ASIC Multiple inter digitated fingers create increased capacitance thus enabling a high signal to noise ratio The fingers are tapered to increase the resonant frequency and also have a high aspect ratio to provide highly stable performance The differential gaps between the static electrode fingers and those of the proof mass provide an air squeeze film with near critical damping Control of the accelerometer is handled by the ASIC Support flexure ayaa Seismic proo
18. e schematics of the accelerometer structure and control loop respectively Sensing axis Fixed support 4 gt Fixed Electrode 2 g f A f f y Fixed Electrode 1 f g f y f f f Proof mass includes fingers C G 18613 Figure 11 5 a Schematic of Accelerometer Structure t Electrode 2 Out of Phase Square Wave at 88kHz on Electrode 2 Sensing axis Electrode 1 JL In Phase Square Wave at 88kHz on Electrode 1 88kHz reference Signal proportional to movement of proof mass Demodulator Amplifier Low pass filter Output signal C G 18540 Figure 11 5 b Schematic of Accelerometer Control Loop Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 26 DMU10 00 0100 132 Rev 4 SILICON D M U1 0 Technical Datasheet SENSING Six Degrees of Freedom Precision MEMS Inertial Measurement Unit www siliconsensing com Notes Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 27 D M U1 0 Technical Datasheet SILICON Six
19. ecuring to an aluminium host structure This information is provided for guidance purposes only the actual torque settings are the responsibility of the host system designer Alignment Dowels used for Calibration and Test 3 199 8x 3188 25 6 22 17 4 O00000 CLL l All dimensions in millimetres Figure 10 1 DMU10 OEM Installation Drawing Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 21 D M U1 0 Technical Datasheet SILICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 3x a 3 5 a 0 5 aa eh oO gt a gt g 2 024 AIA y i ii 799 All dimensions in millimetres 2x R OO Figure 10 2 DMU10 Module Installation Drawing Y X Z Yaw Y Figure 10 3 Axis Definitions Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 22 DMU10 00 0100 132 Rev 4 D
20. f mass Cavity Silicon Through glass via Glass Substrates C G 18538 Figure 11 3 Schematic Section of the Silicon On Glass Accelerometer MEMS Wafer Sub Assembly Pedestal The hub of the MEMS gyro ring is Supported above the ASIC on a 1mm diameter cylindrical silicon pedestal which is bonded to the ring and ASIC using an epoxy resin ASIC The ASIC is a 5 52mm x 3 83mm device fabricated using 0 85um CMOS process ASIC and MEMS are physically separate and are connected electrically by using gold bond wires and thus the ASIC has no MEMS to ASIC internal tracking meaning there is reduced noise pick up and excellent EMC performance Gold bond wires also connect the ASIC to the internal bond pads on the Package Base Package Base and Lid The LCC ceramic Package Base is a multi layer aluminium oxide construction with internal bond wire pads connected through the Package Base via integral multi level tungsten interconnects to a series of external solder pads Similar integral interconnects in the ceramic layers connect the Lid to Vss thus the sensitive elements are inside a Faraday shield for excellent EMC Internal and external pads are electroplated gold on electroplated nickel The Package Base incorporates a seal ring on the upper layer onto which a Kovar metal Lid is seam welded using a rolling resistance electrode thus creating a totally hermetic seal Unlike other MEMS Inertial Sensor packages available on the
21. file format Download www siliconsensing com DMU10 02 0100 408 Interface Off the peg pseudo code and a simple flowchart with message handling instructions for use as a customer aid Download to developing their own interface directly to a DMU10 Inertial www siliconsensing com Measurement Unit via the RS422 interface Questions and Answers Some useful questions asked by customers and how we ve answered them This is an Download informal uncontrolled document intended purely as additional www siliconsensing com information RoHS compliance statement for DMU10 DMU10 is fully compliant with RoHS For details of the materials used in the manufacture please refer to the MDS Report Download www siliconsensing com Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 19 D M U1 O echnical Datasheet Six Degrees of Freedom Precision MEMS Inertial Measurement Unit SILICON SENSING www siliconsensing com 8 1 DMU10 Evaluation Kit The DMU10 Evaluation Kit enables the output data from the DMU10 to be viewed and logged for testing and evaluation purposes Figure 8 1 DMU10 Evaluation Kit 8 1 1 DMU10 Evaluation Kit Contents The DMU10 Evaluation Kit part number DMU10 21 0500 contains the following DMU10
22. hts reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 6 DMU10 00 0100 132 Rev 4 D M U1 0 Technical Datasheet S LICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 5 Typical Performance Characteristics This section shows the typical performance of DMU10 Uncalibrated and Calibrated 5 1 Performance Characteristics Uncalibrated DMU10 01 and DMU10 02 Bias dps Scale Factor Error 0 20 40 Temperature C Temperature C Figure 5 1 Gyroscope Bias Figure 5 2 Gyroscope Scale Factor Error 20 Misalignment Error Distribution of Population mL Tee 0 4 0 15 0 2 0 25 03 035 04 045 05 0 55 0 6 065 0 7 0 75 Tamanta OC Max Non Linearity Error of Full Scale Figure 5 3 Gyroscope Cross Coupling Figure 5 4 Gyroscope Non Linearity Distribution Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 7 D M U1 0 Technical Datasheet S LICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com Typical Performance Characteristics Uncalibrated DMU10 01 and DMU10 02 Bias mg Scale
23. ingle Precision p Theta FP DO8 Spare 15 28 29 Aux 32 Bit pal DO9 Spare i D010 Spare 16 a oe au 16 Bit decimal value D011 Spare BIT Flags n 5 D012 Spare ystem Operation 17 31 BIT Flags 16 Bit decimal value D013 Spare 18 32 en 16 Bit decimal value 22 a BIT Flags BOIS Spare 16 Bit 2 s Complement 19 33 Checksum of the 16 Bit Sum of the Table 7 3 System Startup BIT Flags Previous 0 18 data items Table 7 2 Operational Message Data Output Definitions Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 17 D M U1 0 Technical Datasheet SILICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 7 9 2 System Operation BIT Flags BIT No System Operation BIT Flags These flags indicate errors detected during DMU10 D011 Spare operation These flags are set per DMU10 output D012 Spare message and so may not appear in every returned D013 Spare message because the fault may clear or be D014 Spare intermittent D015 Spare BIT No System Operation BIT Flags Voltage_Regulator_Range_Error Table 7 4 System Operation BIT Flags
24. is deformed into a Cos2 mode which is elliptical in form and has a natural frequency of 22kHz This is depicted in Figure 7 11 4 c In Figure 11 4 c the gyro is powered up but still not rotating At the four Secondary Pick Off nodes located at 45 to the primary axes on the ring perimeter S there is effectively no radial motion S Zero Radial s Motion SPO a Cos20 p Vibration t y Mode at M 22kHz _ Te ea el an a mii a If the gyro is now subjected to applied angular rate as indicated in Figure 11 4 d then this causes the ring Ne e to be subjected to coriolis forces acting at a tangent f to the ring perimeter on the primary axes These forces in turn deform the ring causing radial motion at the Secondary Pick Off transducers It is the motion detected at the Secondary Pick off transducers which is proportional to the applied angular rate The signal is demodulated with respect to the primary motion V which results in a low frequency component which is proportional to angular rate All of the gyro control circuitry is hosted in the ASIC A block diagram of the ASIC functions is given in Figure 1 1 in Section 1 Vv C G 18400 s Resultant Radial Motion Fe Coriolis Force PPO 7 _ N N N N gt n et 7 Vv C G 18400 Sr saii Figure 11 4 d Figure 11 4 a Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlan
25. ize and affordability It contains three oth generation piezoelectric PZT gyroscopes and six accelerometers Outputs from dual accelerometers per axis are averaged to improve precision and reduce uncorrelated noise Available uncalibrated or calibrated over the full operating temperature range DMU10 is supplied either as an OEM or a Module Full Evaluation Kit available see Section 8 for details Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 1 D M U1 0 Technical Datasheet SILICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 3 2 to 5 25V PLi2 LL EXPANSION PORT 3 1V 3 1V REGULATOR TEMPERATURE SENSOR PL1_1 PL1_3 RX PL1_4 RS422 PL1_9 VF TX PL1_10 TX_TRISTATE RS422_TERMINATION MICROCONTROLLER PL1_12 PL1_11 PL1_6 PL1_7 PL1_8 PL1_5 C G 18710 Figure 1 1 DMU10 Functional Block Diagram SILICON SENSING DMU10 fee PT NO DMU10 02 0100 SER NO WWYYXXXX C MADE IN PLYMOUTH UK LELLE j ELE HAANHI a nts OCE All dimensions in millimetres All dimensions in millimetres Figure 1 2 DMU10 OEM Unit Figure 1 3 DMU10 Module Unit Ove
26. l rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 18 DMU10 00 0100 132 Rev 4 D M U1 0 Technical Datasheet S LICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 8 Design Tools and Resources Available item Description of Resource Part Number Order Download LP DMU10 Brochure A one page sales brochure describing the ape i Download key features of the DMU10 Inertial Measurement Unit ne ee www siliconsensing com DMU10 Datasheet Full technical information on all DMU10 Dynamic Measurement Unit part number options Specification and other essential information for assembling DMU10 00 0100 132 and interfacing to DMU10 Inertial Measurement Unit and getting the most out of it Download www siliconsensing com DMU10 Evaluation Kit DMU10 delivered with an R8422 to USB interface plug and play real time display and logging DMU10 21 0500 Order software and two interface cabling solutions DMU10 21 0100 www siliconsensing com unit included DMU10 Presentation A useful presentation describing the features construction principles of operation and applications for the DMU10 Inertial Measurement Unit Download www siliconsensing com DMU10 01 0100 408 Solid Model CAD files for DMU10 Inertial Measurement Unit Available in STP and IGS
27. led when the Run Mode Pin is pulled low 7 6 Operational Message Output The Output Message is output on a RS422 Serial output at 460 800 baud using a non return to zero protocol Each byte contains a start bit logic 0 8 data bits and 2 stop bits logic 1 Data is output in big endian format by default Data is output at a rate of 200 messages per second Each message contains 34 words 68 bytes as described in Table 7 2 The message is transmitted if the Run Mode Pin is High NC If the Run Mode Pin changes to a Low Disable output while the message is being transmitted the message is completed before the output is disabled 7 7 Sensor Sampling and Synchronisation The Inertial Sensors within DMU10 are all sampled at 1 000Hz The Sync Pulse on the connector is set HIGH at the start of the sampling and returned to LOW when the last Inertial Sensor is sampled Pulses are therefore seen on the connector at 1 000HZz The Inertial Sensor measurements are then filtered with a 2nd order low pass filter also running at 1000Hz The factory default setting for this filter has a corner frequency of gt 85Hz The internal sequence for DMU10 is e Cycle 1 Sample Sensors 2nd order Filter e Cycle 2 Sample Sensors 2nd order Filter Calculate Sensor Compensation e Cycle 3 Sample Sensors 2nd order Filter Apply Sensor Compensation e Cycle 4 Sample Sensors 2nd order Filter Calculate Delta Theta and
28. or 28 AWG wires 7 4 Pin Information Pin Label Signal imou 1 Ground connected of the DMU10 La o exo 5 LBV Input voltage to the DMU10 Can be between 3 2V and 5 25V The negative receive connection 3 Rx Lo required for the RS422 communication The positive receive connection i required for the R8422 communication R Microprocessor reset Pin is pulled low to reset the device Reset l l Suggested implementation using TTL logic Device Enable Disable Pin is pulled high or not connected nth ods to enable the device Pin is pulled low to disable the device Suggested implementation using TTL logic A Analogue input channel which integrates a signal into the output message of the DMU10 This UX functionality can be used to allow the user to synchronise with a Known input clock Output signal that can be used by Sync an external system to synchronise with DMU10 The negative transmit connection Tx Lo required for the RS422 communication The positive transmit connection TX Hi required for the RS422 Communication Not electrically connected Used by SSSL for programming Factory Use purposes and should not be interfaced with Table 7 1 Pin Information 7 5 Communications with DMU10 The Run Mode pin on the connector is used to control the output from the DMU10 The Free Run or Enabled mode is active when the Pin is floating not connected and the output will be enabled The DMU10 output is disab
29. rall Dimensions Overall Dimensions Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 2 DMU10 00 0100 132 Rev 4 SILICON D M Ut 0 Technical Datasheet SENSING Six Degrees of Freedom Precision MEMS Inertial Measurement Unit www siliconsensing com 2 Ordering Information Calibration UN Uncalibrated OT Over Temperature Calibration Dimensions DMU10 01 0100 Bare PCB with four 41 x22x106 mounting holes DMU10 21 0100 DMU10 02 0100 A two part anodised aluminium non hermetic 45 x26 16 housing Three mounting lugs DMU10 22 0100 DMU10 Module Unit Customer evaluation kit comprising a DMU10 21 0100 RS422 Side at a Not Applicable DMU10 21 0500 Software Cables and Connectors Instruction Manual DMU10 OEM Evaluation Kit Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 3 DMU10 00 0100 132 Rev 4 D M U1 0 Technical Datasheet SILICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 3 Performance Calibration UN Uncalibrated OT Over Temperature Calibration Angular Rate Roll Pitch Yaw
30. ring design enable close tolerance geometrical properties for precise balance and thermal stability and unlike other MEMS gyros there are no small gaps to create problems of interference and stiction These features contribute significantly to DMU10 s bias and scale factor stability over temperature and vibration and shock immunity Another advantage of the design is its inherent immunity to acceleration induced rate error or g sensitivity Piezoelectric strain thin film actuators transducers are attached to the upper surface of the silicon ring perimeter and are electrically connected to bond pads on the ring hub via tracks on the spokes These actuate or drive the ring into its Cos20 mode of vibration at a frequency of 22kKHz or detect radial motion of the ring perimeter either caused by the primary drive actuator or by the coriolis force effect when the gyro Is rotating about its sensing axis There is a single pair of primary drive actuators and a single pair of primary pick off transducers and two pairs of secondary pick off transducers The combination of transducer technology and eight secondary pick off transducers improves the DMU10 s signal to noise ratio the benefit of which is a very low noise device with excellent bias over temperature performance Silicon MEMS Dual Axis Accelerometer The Combi Sensor dual axis open loop accelerometer is a one piece resonating silicon MEMS structure anodically bonde
31. rom which the gyro derives angular rate Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Page 24 DMU10 00 0100 132 Rev 4 D M U1 0 Technical Datasheet S LICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com The transducers produce a double sideband PPO suppressed carrier signal which is demodulated back to a baseband This gives the user complete SPO SPO flexibility over in system performance and makes the transduction completely independent of DC or low frequency parametric conditions of the electronics Referring to Figures 11 4 a to 11 4 d Figure 11 4 a shows the structure of the silicon MEMS ring Figure 11 4 b shows the ring diagrammatically the spokes actuators and transducers removed for SPO SPO clarity indicating the Primary Drive actuators single pair Primary Pick Off transducers single pair and Secondary Pick Off transducers two pairs In Figure 11 4 6 the annular ring is circular and is Figure 11 4 b representative of the gyro when unpowered PD PD PPO C G 18399 When powered up the ring is excited along its primary axes using the Primary Drive actuators and Primary a Pick Off transducers acting in a closed loop control system within the ASIC The circular ring
32. sured using the Allan Variance method Bias Repeatability 4 BiaSwarmup Bi Stoto Bi Sageing BlaStemperature Bias Repeatability mg Over operating Acc Cross Coupling temperature range 3dB point User programmable Wide band noise at Temperature Output Range C All lt 45 lt 100 Exceeds operational temperature range Accuracy C All 4 In the operational temperature range Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice Acc Bandwidth Hz DMU10 00 0100 132 Rev 4 Page 5 D M U1 0 Technical Datasheet SILICON Six Degrees of Freedom Precision SENSING MEMS Inertial Measurement Unit www siliconsensing com 4 Environment Power and Physical ie perene TENPE e 40 85 Full specification Range C Storage Temperature i Range C Oos Do lo ow oo Operational Random Vibration g rms oe o e siecle Non Operational Random 10 20Hz to OKHz Vibration g rms Communication Protocol es Standard po RS 422 pe Full duplex communication Data Rate Hz 200 Default Sacr programmable future feature Baud Rate BPS 460 800 Default User programmable future feature termination resistor Physical OEM Physical Module Mass grams Copyright 2015 Silicon Sensing Systems Limited All rig
33. t www siliconsensing com Typical Performance Characteristics Uncalibrated and Calibrated Noise mg rms Acc output in mg rt hz 10 1 4 o 1 0 1 o F in Hz requency in Temperature C Figure 5 25 Accelerometer Spectral Noise Figure 5 26 Accelerometer Noise over Temperature Copyright 2015 Silicon Sensing Systems Limited All rights reserved Silicon Sensing is an Atlantic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 13 D M U1 O echnical Datasheet Six Degrees of Freedom Precision MEMS Inertial Measurement Unit SILICON SENSING www siliconsensing com 6 Glossary of Terms ADC Analogue to Digital Converter ARW Angle Random Walk AWG American Wire Gauge BPS Bits Per Second or Baud Rate BW Bandwidth C Celsius or Centigrade DAC Digital to Analogue Converter DPH Degrees Per Hour DPS Degrees Per Second DRIE Deep Reactive lon Etch EMC Electro Magnetic Compatibility ESD Electro Static Damage F Farads h Hour HBM Human Body Model Hz Hertz Cycles Per Second K Kilo MDS Material Datasheet MEMS Micro Electro Mechanical Systems mV Milli Volts NEC Not Electrically Connected NL Scale Factor Non Linearity OEM Original Equipment Manufacturer OT Over Temperature PD Primary Drive PP Primary Pick Off RC Resistor and Capacitor filter RT Room Temperature S Seconds OF scale Factor SMT
34. tic Inertial Systems Sumitomo Precision Products joint venture company Specification subject to change without notice DMU10 00 0100 132 Rev 4 Page 25 D M U1 O echnical Datasheet Six Degrees of Freedom Precision MEMS Inertial Measurement Unit SILICON SENSING www siliconsensing com Theory of Operation Accelerometer The accelerometer contains a seismic proof mass with multiple fingers suspended via a spring from a fixed supporting structure The supporting structure is anodically bonded to the top and bottom glass substrates and thereby fixed to the sensor package base When the accelerometer is subjected to a linear acceleration along its sensitive axis the proof mass tends to resist motion due to its own inertia therefore the mass and it s fingers becomes displaced with respect to the interdigitated fixed electrode fingers which are also fixed to glass substrates Air between the fingers provides a damping effect This displacement induces a differential capacitance between the moving and fixed silicon fingers which is proportional to the applied acceleration Capacitor plate groups are electrically connected in pairs at the top and bottom of the proof mass In phase and anti ohase waveforms are applied by the ASIC separately to the left and right finger groups The demodulated waveforms provide a signal output proportional to linear acceleration Figures 11 5 a and 11 5 b provid
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