SCC1300-D02 Data Sheet SCC1300-D02 Combined Gyroscope and 3-axis Accelerometer with digital SPI interfaces Features * * * * * * * * * * * Applications 100 /s angular rate measurement range 2 g 3-axis acceleration measurement range Angular rate measurement around X axis Angular rate sensor exceptionally insensitive to mechanical vibrations and shocks Superior bias stability for MEMS gyroscopes (<1/h) Digital SPI interfacing Enhanced self diagnostics features Small size: 8.5 x 18.7 x 4.5 mm (w x l x h) RoHS compliant robust packaging suitable for leadfree soldering process and SMD mounting Proven capacitive 3D-MEMS technology Temperature range -40 C...+125 C The SCC1300-D02 is targeted at applications demanding high stability with tough environmental requirements. Typical applications include: * Inertial Measurement Units (IMUs) for highly demanding environments * Platform stabilization and control * Motion analysis and control * Roll over detection * Robotic control systems * Guidance systems * Navigation systems Overview The SCC1300-D02 is a combined high performance gyroscope and accelerometer component. The sensor is based on Murata's proven capacitive 3D-MEMS technology. The component integrates angular rate and acceleration sensing together with flexible separate digital SPI interfaces. The small robust packaging guarantees reliable operation over the product's lifetime. The housing is suitable for SMD mounting. The component is compatible with RoHS and ELV directives. The SCC1300-D02 is designed, manufactured and tested for high stability, reliability and quality requirements. The angular rate and acceleration sensors provide highly stable output over wide ranges of temperature and mechanical noise. The angular rate sensor bias stability is in the elite of MEMS gyros. It is also exceptionally insensitive to all mechanical vibrations and shocks. The component has several advanced self diagnostics features. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 1/34 Rev. D SCC1300-D02 TABLE OF CONTENTS 1 Introduction ..................................................................................................................................... 4 2 Specifications.................................................................................................................................. 4 2.1 Performance Specifications for Gyroscope .............................................................................................. 4 2.2 Performance Specifications for Accelerometer ........................................................................................ 5 2.3 Absolute Maximum Ratings ........................................................................................................................ 6 2.4 Pin Description ............................................................................................................................................. 6 2.5 Digital I/O Specification ............................................................................................................................... 8 2.6 SPI AC Characteristics ................................................................................................................................ 9 2.7 Measurement Axis and Directions ........................................................................................................... 10 2.8 Package Characteristics ............................................................................................................................ 11 2.8.1 Package Outline Drawing ............................................................................................................... 11 2.8.2 PCB Footprint .................................................................................................................................. 12 2.9 Abbreviations ............................................................................................................................................. 12 3 General Product Description ........................................................................................................ 13 3.1 Factory Calibration..................................................................................................................................... 13 4 Reset and Power Up ..................................................................................................................... 14 4.1 Gyro Power-up Sequence ......................................................................................................................... 14 4.1.1 Gyro Reset ....................................................................................................................................... 14 4.2 Accelerometer Power-up Sequence ......................................................................................................... 14 4.2.1 Accelerometer reset ....................................................................................................................... 15 5 Component Interfacing ................................................................................................................. 16 5.1 SPI Interfaces.............................................................................................................................................. 16 5.2 Gyroscope Interface .................................................................................................................................. 16 5.2.1 Gyro SPI Communication Overview ............................................................................................. 16 5.2.2 Gyro SPI Read Frame ..................................................................................................................... 17 5.2.3 Gyro SPI Write Frame ..................................................................................................................... 19 5.2.4 Gyro SPI Mixed Access Mode........................................................................................................ 20 5.3 Gyroscope ASIC Addressing Space ........................................................................................................ 21 5.3.1 Angular Rate Output Register ....................................................................................................... 21 5.3.1.1 Example of Rate Data Conversion .................................................................................... 22 5.3.2 Gyro Temperature Output Register .............................................................................................. 22 5.3.2.1 Example of GYRO Temperature Conversion ................................................................... 22 5.4 Accelerometer Interface ............................................................................................................................ 23 5.4.1 Accelerometer SPI Communication Overview ............................................................................. 23 5.4.2 Accelerometer SPI Read Frame..................................................................................................... 24 5.4.3 Accelerometer SPI Write Frame .................................................................................................... 25 5.4.4 Accelerometer Decremented Register Read Operation .............................................................. 25 Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 2/34 Rev. D SCC1300-D02 5.4.5 Accelerometer SPI Error Conditioning (Self Diagnostics) ......................................................... 26 5.4.5.1 FRME bit............................................................................................................................... 26 5.4.5.2 PORST bit ............................................................................................................................ 26 5.4.5.3 ST bit .................................................................................................................................... 26 5.4.5.4 SAT bit .................................................................................................................................. 26 5.4.5.5 aPAR bit ............................................................................................................................... 26 5.4.5.6 dPAR bit ............................................................................................................................... 27 5.4.5.7 Fixed bits ............................................................................................................................. 27 5.4.5.8 SPI error effect on acceleration output data .................................................................... 27 5.5 Accelerometer ASIC Addressing Space .................................................................................................. 28 5.5.1 Control Register (CTRL) ................................................................................................................. 29 5.5.2 Acceleration output registers ........................................................................................................ 29 5.5.2.1 Example of acceleration data conversion ........................................................................ 29 5.5.3 Accelerometer Temperature Output Registers ............................................................................ 30 5.5.3.1 Example of accelerometer temperature conversion ....................................................... 30 6 Application Information ................................................................................................................ 31 6.1 Application Circuitry and External Component Characteristics ........................................................... 31 6.1.1 Separate Analog and Digital Ground Layers with Long Power Supply Lines .......................... 32 6.2 Boost Regulator and Power Supply Decoupling in Layout ................................................................... 33 6.2.1 Layout Example............................................................................................................................... 33 6.2.2 Thermal Connection ....................................................................................................................... 34 6.3 Assembly Instructions ............................................................................................................................... 34 Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 3/34 Rev. D SCC1300-D02 1 Introduction This document contains essential technical information about the SCC1300 sensor, including specifications, SPI interface descriptions, user accessible register details, electrical properties and application information. This document should be used as a reference when designing in SCC1300 component. 2 2.1 Specifications Performance Specifications for Gyroscope Table 1. Gyroscope performance specifications (Avdd = 5 V, Dvdd = 3.3 V and ambient temperature unless otherwise specified). Parameter Analog supply voltage Analog supply current Digital supply voltage Digital supply current Operating range B) Offset error Offset over temperature Min 4.75 24 3.0 16 -100 -1 -0.6 -0.3 -0.3 Temperature range -40 ... +125 C Temperature range -40 ... +125 C Measurement axis X Offset drift velocity C) Offset short term instability C) Angular random walk (ARW) Sensitivity Sensitivity over temperature B) Total sensitivity error Nonlinearity Noise (RMS) Noise Density Cross-axis sensitivity G-sensitivity Shock sensitivity Shock recovery time Amplitude response Power on setup time Output data rate Output load SPI clock rate A) A) Condition Temperature range -40 ... +125 C Temperature range -10 ... +60 C Temperature gradient 2.5 K/min A) Typ 5 26 3.3 20 Max 5.25 29.5 3.6 24 100 1 0.6 0.3 0.3 Unit V mA V mA /s /s /s /s (/s)/min /h <1 0.45 50 Temperature range -40 ... +125 C / h -1 -2 -0.5 Temperature range -40 ... +125 C 0.06 0.0085 LSB/(/s) % % /s /s 1 2 0.5 0.1 (/s)/ Hz 1.7 0.1 2.0 50.0 -0.1 50g, 6ms -3dB frequency % (/s)/g /s ms Hz s kHz pF MHz 50 0.8 2 200 8 0.1 MIN/MAX values are 3 sigma variation limits from validation test population. Including calibration error and drift over lifetime. Based on Allan variance measurements (Figure 1b). Cross-axis sensitivity is the maximum sensitivity in the plane perpendicular to the measuring direction relative to the sensitivity in the measuring direction. The specified limit must not be exceeded by either axis. B) C) D) SCC1300-D02 Gyro Bias vs. Temperature SCC1300-D02 Allan Variance Curve 0.6 100 0.2 +3sigma 0 -40 -20 0 20 40 60 80 100 120 AVG -3sigma -0.2 Allan deviation [/h] Angular Rate Offset [/s] 0.4 10 +3 sigma Average 1 -0.4 -0.6 0.1 0.1 -0.8 1 10 100 1000 10000 100000 tau [s] Temperature [C] Figure 1 a) SCC1300-D02 Gyroscope offset over full temperature range, b) Allan variance curve Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 4/34 Rev. D SCC1300-D02 2.2 Performance Specifications for Accelerometer Table 2. Accelerometer performance specifications (Vdd = 3.3V and ambient temperature unless otherwise specified). Parameter Analog and digital supply voltage Current consumption Measurement range B) Offset error C) Offset temperature drift Sensitivity Total sensitivity error Sensitivity calibration error Sensitivity temperature drift Linearity error Cross-Axis sensitivity D) Zero acceleration output E) Amplitude response Noise Power on setup time Output data rate Output load SPI clock rate A) B) C) D) E) Condition Active mode Power down mode Measurement axes X, Y & Z @25 C 5C Temperature range -40 ... +125 C 13 bit output Between 3 Temperature range -40 ... +125 C @25 C 5C Temperature range -40 ... +125 C +1g ... -1g range 2-complement format -3dB frequency A) Min 3.0 Typ 3.3 3 0.12 -2 -16 -18 Max 3.6 5 2 16 18 1800 0.032 -4 -0.5 -0.8 -20 -2.5 4 0.5 0.8 20 2.5 0 30 3 55 5 0.1 2000 50 8 A) Unit V mA mA g mg mg LSB/g /LSB % FS % FS % FS mg % LSB Hz mg RMS s Hz pF MHz MIN/MAX values are 3 sigma variation limits from validation test population. Includes offset deviation from 0g value, including calibration error and drift over lifetime. Biggest change of output from RT value due to temperature. Cross-axis sensitivity is the maximum sensitivity in the plane perpendicular to the measuring direction relative to the sensitivity in the measuring direction. It is calculated as the geometric sum of the sensitivities in two perpendicular directions (Sx and Sy) in this plane. See Figure 2. Figure 2. SCC1300-D02 Accelerometer frequency response curves Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 5/34 Rev. D SCC1300-D02 2.3 Absolute Maximum Ratings Table 3. Absolute maximum ratings of the SCC1300 sensor. Parameter Gyroscope supply voltages Analog supply voltage, AVDD_G Digital supply voltage, DVDD_G Maximum voltage at analog input/output pins Maximum voltage at digital input/output pins Accelerometer supply voltages Digital supply voltage, DVDD_A Analog supply voltage, AVDD_A Maximum voltage at input / output pins General Component Ratings Operating temperature Storage temperature Condition Max 96h Maximum junction temperature during lifetime. Note: device has to be functional, but not in full spec. Mechanical Shock ESD Ultrasonic agitation (cleaning, welding, etc.) 2.4 Min Typ Max Unit -0.5 -0.3 -0.3 -0.3 7 3.6 AVDD_G + 0.3V DVDD_G + 0.3 V V -0.3 -0.5 -0.3 3.6 7.0 DVDD_A + 0.3V V V V -40 -40 -40 125 125 150 155 C C C C 2 500 g kV V 3000 HBM CDM Prohibited V Pin Description The pinout for the SCC1300 is presented below in Figure 3. (See Table 4 for pin description) HEAT HEAT REFGND_G RESERVED VREFP_G RESERVED EXTRESN_G AVSS_G RESERVED AVDD_G AHVVDDS_G RESERVED LHV RESERVED DVDD_G CSB_G DVSS_G SCK_G MISO_G MOSI_G SCK_A MISO_A MOSI_A CSB_A RESERVED AVDD_A DVDD_A AVSS_A DVSS_A RESERVED HEAT HEAT Figure 3. SCC1300 pinout diagram. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 6/34 Rev. D SCC1300-D02 Table 4. SCC1300 pin description pin # 1 2 3 Name HEAT REFGND_G VREFP_G Type 1) AI AI AO 4 EXTRESN_G DI 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 RESERVED AHVVDDS_G LHV DVDD_G DVSS_G MISO_G SCK_A MOSI_A RESERVED DVDD_A DVSS_A HEAT HEAT RESERVED AVSS_A AVDD_A CSB_A MISO_A MOSI_G SCK_G CSB_G RESERVED RESERVED AVDD_G AVSS_G RESERVED RESERVED HEAT R AO AI AI AI DOZ DI DI R AI AI AI AI R AI AI DI DOZ DI DI DI R R AI AI R R AI PD/PU/HV 2) PU HV (~30V) HV (~30V) PD PD PU PD PD PU Description Heat sink connection, connect to AVSS_G. Analog reference ground, connect to AVSS_G Connection for External C for positive reference voltage. External Reset, 3.3V Schmitt-trigger input with internal pull-up, High-low transition causes system restart Factory use only, leave floating Connection for External C for high voltage analog supply. High voltage pad ~30V Connection for inductor for high voltage generation, high voltage pad ~30V Digital Supply Voltage Digital Supply Return Data Out of SPI Interface, 3.3V level. Clk Signal of SPI Interface, 3.3V Schmitt-trigger input Data In of SPI Interface, 3.3V Schmitt-trigger input Factory use only, leave floating Digital Supply Voltage Digital Supply Return Heat sink connection, connect to AVSS_G. Heat sink connection, connect to AVSS_G. Factory use only, leave floating Analog Supply Return Analog Supply Voltage Chip Select of SPI Interface, 3.3V Schmitt-trigger input Data Out of SPI Interface, 3.3V level Data In of SPI Interface, 3.3V Schmitt-trigger input Clk Signal of SPI Interface, 3.3V Schmitt-trigger input Chip Select of SPI Interface, 3.3V Schmitt-trigger input Factory use only, leave floating Factory use only, leave floating Analog Supply Voltage Analog Supply Return Factory use only, leave floating Factory use only, leave floating Heat sink connection, connect to AVSS_G. Notes: 1) A = Analog, D = Digital, I = Input, O = Output, Z = Tristate Output, R = Reserved 2) PU = internal pull up, PD = internal pull down, HV = high voltage Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 7/34 Rev. D SCC1300-D02 2.5 Digital I/O Specification Table 5 (gyroscope interface) and Table 6 (accelerometer interface) below describe the DC characteristics of the SCC1300 sensor's digital I/O pins. The digital supply voltage is 3.3V unless otherwise specified. Current flowing into the circuit has a positive value. Table 5. SCC1300 gyroscope SPI interface DC characteristics Parameter Conditions Input terminal CSB_G Pull up current VIN = 0V Input high voltage DVDD_G = 3.3V Input low voltage DVDD_G = 3.3V Hysteresis DVDD_G = 3.3V Input terminal SCK_G Input high voltage DVDD_G = 3.3V Input low voltage DVDD_G = 3.3V Hysteresis DVDD_G = 3.3V Input leakage current 0 < VMISO < 3.3V Output terminal MOSI_G Input high voltage DVDD_G = 3.3V Input low voltage DVDD_G = 3.3V Hysteresis DVDD_G = 3.3V Pull down current VIN = VDVDD_G Output terminal MISO_G (Tri-state) Output high voltage IOUT = -1mA Output low voltage Capacitive load IOUT = -50A 0 VMISO 3.3V Symbol Min IPU VIH VIL VHYST 10 2 VIH VIL VHYST ILEAK Typ Max Unit 50 DVDD_G 0.8 A V V V DVDD_G 0.8 V V V uA 0.3 2 0.3 -1 VIH VIL VHYST ILEAK 0.3 10 VOH 1 2 DVDD_G 0.8 50 V V V uA DVDD_G -0.5V V DVDD_G -0.2V 0.5 200 V V pF Max Unit 50 DVDD_A 0.8 A V V V 50 DVDD_A 0.8 VOL Table 6. SCC1300 accelerometer SPI interface DC characteristics Parameter Conditions Input terminal CSB_A Pull up current VIN = V Input high voltage DVDD_A = 3.3V Input low voltage DVDD_A = 3.3V Hysteresis DVDD_A = 3.3V Input terminal MOSI_A, SCK_A Pull down current VIN = 3.3V Input high voltage DVDD_A = 3.3V Input low voltage DVDD_A = 3.3V Hysteresis DVDD_A = 3.3V Output terminal MISO_A Output high voltage I > -1mA DVDD_A = 3.3V Output low voltage I < 1 mA Capacitive load Tri-state leakage 0 < VMISO < 3.3V Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 Symbol Min IPU VIH VIL VHYST 10 2 Typ 0.18 IPD VIH VL VHYST 0.18 A V V V VOH DVDD_A - 0.5V V 10 2 VOL ILEAK -3 0.5 50 3 V pF uA 8/34 Rev. D SCC1300-D02 2.6 SPI AC Characteristics The AC characteristics of the SCC1300 are defined in Figure 4 and Table 7. TLS1 TCH TCL TLS2 TLH CSB_G, CSB_A SCK_G, SCK_A THOL MOSI_G, MOSI_A TVAL1 MISO_G, MISO_A TSET MSB in DATA in LSB in TVAL2 MSB out TLZ DATA out LSB out Figure 4. Timing diagram of SPI communication Table 7. Timing characteristics of SPI communication Parameter FSPI TSPI TCH TCL TLS1 TVAL1 TSET THOL TVAL2 Condition Min 0.1 SCK_G, SCK_A high time SCK_G, SCK_A low time CSB_G, CSB_A setup time Delay CSB_G -> MISO_G Delay CSB_A -> MISO_A MOSI_G, MOSI_A setup time MOSI_G, MOSI_A data hold time 45 45 45 TLS2 Delay SCK_G -> MISO_G Delay SCK_A -> MISO_A CSB_G, CSB_A hold time TLZ TRISE TFALL TLH Tri-state delay time Rise time of the SCK_G, SCK_A Fall time of the SCK_G, SCK_A Time between SPI cycles Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 Typ Max 8 Unit MHz 30 ns ns ns ns 1/ FSPI TSPI /2 TSPI /2 TSPI /2 30 ns ns 30 40 45 TSPI /2 ns 30 10 10 125 ns ns ns ns ns 9/34 Rev. D SCC1300-D02 2.7 Measurement Axis and Directions The positive/negative acceleration and angular rate measurement directions of the SCC1300 are shown below in Figure 5. Figure 5. Acceleration and angular rate measurement directions of the SCC1300 Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 10/34 Rev. D SCC1300-D02 2.8 2.8.1 Package Characteristics Package Outline Drawing The package outline and dimensions of the SCC1300 are presented in Figure 6 and Table 8. Figure 6. Package outline and dimensions of the SCC1300. All tolerances are according to ISO2768-f (see table below) unless otherwise specified. Limits for linear measures (ISO2768-f) Tolerance class f (fine) 0.5 to 3 0.05 Limits in mm for nominal size in mm Above 3 to 6 Above 6 to 30 0.05 0.1 Above 30 to 120 0.15 Table 8. Package dimensions of the SCC1300 Component Length Width Width Height Parameter Without leads Without leads With leads With leads (including stand-off and EMC lead) Lead pitch Murata Electronics Oy www.muratamems.fi Min Typ 19.71 8.5 12.15 4.60 1.0 Subject to changes Doc.Nr. 82113000 Max Unit mm mm mm mm mm 11/34 Rev. D SCC1300-D02 2.8.2 PCB Footprint The footprint dimensions of the SCC1300 are presented in Figure 7 and Table 9. Figure 7. Footprint of the SCC1300 Table 9. Footprint dimensions of the SCC1300 Component Footprint length Footprint width Footprint lead pitch Footprint lead length Footprint lead width 2.9 Parameter Without lead footprints Without lead footprints Long side leads Long side leads Min Typ 15.7 13.0 1.0 2.20 0.7 Max Unit mm mm mm mm mm Abbreviations ASIC SPI RT STC STS ARW DPS Murata Electronics Oy www.muratamems.fi Application Specific Integrated Circuit Serial Peripheral Interface Room Temperature Self Test Continuous (continuous self testing of accelerometer element) Self Test Static (gravitation based self test of accelerometer element) Angular random walk Degrees per second Subject to changes Doc.Nr. 82113000 12/34 Rev. D SCC1300-D02 3 General Product Description The SCC1300 sensor consists of independent acceleration and angular rate sensing elements and separate independent Application Specific Integrated Circuits (ASICs) used to sense and control those elements. Figure 8 represents an upper level block diagram of the component. Both ASICs have their own independent digital SPI interfaces used to control and read the accelerometer and the gyroscope. Figure 8. Block diagram of the SCC1300 The angular rate and acceleration sensing elements are manufactured using Murata's proprietary High Aspect Ratio (HAR) 3D-MEMS process, which enables robust, extremely stable and low noise capacitive sensors. The acceleration sensing element consists of four acceleration-sensitive masses. Acceleration causes a capacitance change that is converted into a voltage change in the signal conditioning ASIC. The angular rate sensing element consists of moving masses that are purposely exited to inplane drive motion. Rotation in the sensitive direction causes out-of-plane movement that can be measured as capacitance change with the signal conditioning ASIC. 3.1 Factory Calibration SCC1300 sensors are factory calibrated. No separate calibration is required in the application. Parameters that are trimmed during production include sensitivities, offsets and frequency responses. Calibration parameters are stored to non-volatile memory during manufacturing. The parameters are read automatically from the internal non-volatile memory during start-up. It should be noted that assembly can cause minor offset/bias errors to the sensor output. If the best possible offset/bias accuracy is required, system level offset/bias calibration (zeroing) after assembly is recommended. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 13/34 Rev. D SCC1300-D02 4 Reset and Power Up After start-up the angular rate and acceleration data is immediately available through SPI registers. There is no need to initialize the gyroscope or accelerometer before starting to use it. If the application requires operation correctness to be monitored, several self diagnostic features are available. For more details about enabling the self diagnostic features, refer to the gyro and accelerometer power-up sequences (Sections 4.1 and 4.2). 4.1 Gyro Power-up Sequence After power-up read the Status register (0x08) twice to clear self diagnostic error flags (see Table 12 for more details about gyro self diagnostics). Angular rate data is available immediately after start-up without any additional configuration commands. Table 10. Gyroscope power-up sequence of the SCC1300 Procedure Set VDVDD_G V=3.0...3.6V Set VAVDD_G V=4.75...5.25V Wait 800 ms Read Status register (08h) two times 4.1.1 Function Acknowledge error flags after start up Gyro Reset The SCC1300 Gyroscope can be reset by writing 0x04 to the IC Identification register (address 07h) or by using the external active low reset pin (EXTRESN_G). Power supplies should be within the specified range before the reset pin can be released. Please follow the gyro power-up sequence after reset (Table 10). 4.2 Accelerometer Power-up Sequence No initial configuration is needed before starting to measure acceleration. However, if the device's self diagnostic features are being used, the following operations need to be performed after powering-up the device (see section 5.4.5 for more details about the accelerometer's self diagnostics). Table 11. Accelerometer power-up sequence of the SCC1300 Procedure Function Set Vdd = 3.0...3.6 V Wait 35 ms Read INT_STATUS Release part from reset Memory reading and self-diagnostic. Settling of signal path Acknowledge for possible saturation (SAT-bit) Check that memory checksum passed Set PORST = 0 Set PORST = 0, Start STC Set PORST = 0, Start STC, Start STS Write CTRL = 00000000 or CTRL = 00001000 or CTRL = 00001010 Wait 10 ms Read CTRL STS calculation Check that STC is on, if enabled Check that STS is over, if enabled Read Z_MSB, Z_LSB, Y_MSB, Y_LSB, X_MSB, X_LSB Read acceleration data Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 Check SPI frame fixed bits SPI ST = 0 SPI frame fixed bits SPI FRME = 0 SPI ST = 0 SPI SAT = 0 CTRL.ST = 1 CTRL.ST_CFG = 0 SPI frame fixed bits SPI FRME = 0 SPI PORST = 0 SPI ST = 0 SPI SAT = 0 dPAR, data parity SPI frame fixed bits SPI FRME = 0 SPI PORST = 0 SPI ST = 0 SPI SAT = 0 dPAR, data parity 14/34 Rev. D SCC1300-D02 4.2.1 Accelerometer reset The accelerometer can be reset by writing 0Ch, 05h, 0Fh (in this order) into the RESET register (address 03h). If the accelerometer's self diagnostic features are being used, the power-up sequence should be executed after reset (Table 11). Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 15/34 Rev. D SCC1300-D02 5 Component Interfacing 5.1 SPI Interfaces The SCC1300 sensor has individual SPI interfaces for the accelerometer and angular rate sensor, and they need to be addressed separately. Both interfaces have their own 4-wire interconnection pins in the component package. SPI communication transfers data between the SPI master and registers of the SCC1300's ASICs. The SCC1300's ASICs always operate as slave devices in master-slave operation mode. 3-wire SPI connection cannot be used. SCC1300 angular rate sensor's ASIC SPI interface: MOSI_G MISO_G SCK_G CSB_G master out slave in master in slave out serial clock chip select (active low) P ASIC ASIC P P ASIC P ASIC SCC1300 accelerometer's ASIC SPI interface: MOSI_A MISO_A SCK_A CSB_A master out slave in master in slave out serial clock chip select (active low) P ASIC ASIC P P ASIC P ASIC PLEASE NOTE THAT EXACTLY THE SAME SPI ROUTINES DO NOT WORK FOR BOTH ASICS! For example, the SCC1300 accelerometer ASIC uses 8-bit addressing, while the SCC1300 angular rate sensor ASIC uses 16-bit addressing. Both SPI interfaces and instructions for using them are explained separately in the following chapters. For more details, please refer to "Technical Note 92: SPI Communication with SCC1300". 5.2 Gyroscope Interface This chapter describes the SCC1300 angular rate sensor ASIC interface and how to use it. The angular rate sensor ASIC SPI interface uses 16-bit addressing. 5.2.1 Gyro SPI Communication Overview The SPI communication is based on 16-bit words. The SPI frames consist of a multiple of these 16-bit words. Figure 9 shows an example of a single SPI data transmission. The gyro captures data on the SCK's rising edge (MOSI line) and data is propagated on the SCK's falling edge (MISO line). This is equal to SPI Mode 0 (CPOL = 0 and CPHA = 0). The SPI transmission is always started with the CSB falling edge and terminated with the CSB rising edge. The basic read/write data frame consists of two 16-bit words. The first word contains a register address, while the second word contains the register content to be written or read (see timing diagram in Figure 9). Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 16/34 Rev. D SCC1300-D02 Figure 9. SPI communication timing diagram After the CSB falling edge the device interprets the first 16-bit word as a 7-bit register address and a read/write operation bit. Remaining bits shall be set to zero. Bit [0] of the 16-bit word is used as an odd parity bit. The 16-bit address word is shown below in detail: MOSI Address Word: D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 0 0 0 0 0 0 ADR6 ADR5 ADR4 ADR3 ADR2 ADR1 ADR0 RW ADR[6:0] : RW : Par odd : D1 D0 Fixed 0 Par odd Register address RW = 1 : Write access RW = 0 : Read access Odd parity bit. Par odd = 0 : the number of ones in the address word (D15:D1) is odd. Par odd = 1 : the number of ones in the address word (D15:D1) is even. The ADR bits are used to select an internal register of the device; the RW bit selects the access mode for the selected register. The par odd bit has to be calculated and inserted by the master in order to complete the transmission. 5.2.2 Gyro SPI Read Frame When the address word bit RW is `0', the master performs a read access on the register selected by the register address bits (ADR). After transmission of the address word, the master has to send an additional word (zero vector) to clock the data out from the MOSI. Data is transferred out from the MOSI MSB first. Example of how to read the rate output MCU begins the communication by sending the address word (Rate_X register address is 00h, RW='0' and Par odd='1') followed by the zero vector (with correct parity; in this case `Par odd' bit value will be 1). The zero vector is necessary for the sensor to be able to reply to the MCU during the last 16-bit frame. The sensor replies by sending first the status bits followed by the rate data. MOSI: 0x0001 0x0001 MISO: 0x3FFE 0xXXXX The complete read frame transmission length is 32 bits (see Figure 10 below). Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 17/34 Rev. D SCC1300-D02 Figure 10. Complete gyroscope read frame Encoding of the MISO status flags are shown below. st Status flags (1 16-bit word on the MISO line) in case status flags are cleared after gyro start-up (see Section 4.1): D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 s_ok Par odd S_OK is generated out of the monitoring flags in the status register (08h). Data word (2 nd 16-bit word on the MISO line): D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 DO13 DO12 DO11 DO10 DO9 DO8 DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0 s_ok Par odd DO[13:0] : S_OK: Par odd : Value of the angular rate register (14 bits) Sensor OK flag Odd parity bit. Par odd = 0 : the number of ones in the data word (D15:D1) is odd. Par odd = 1 : the number of ones in the data word (D15:D1) is even. See section 5.3.1 for details on angular rate data conversion. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 18/34 Rev. D SCC1300-D02 5.2.3 Gyro SPI Write Frame When the address word bit RW is `1', the master performs a write access on the register selected by the register address (ADR). The SCC1300 writes the next word transmitted by the master (data word) in the selected register and sends the data that has been previously stored in this register out from the MISO. If the device is addressed with a non-existent register address, the response from the MISO will be 0x0000. The following table shows data encoding for write access: Data word: D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 DI14 DI13 DI12 DI11 DI10 DI9 DI8 DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0 Par odd DI[14:0] : Par odd : Data value for write access (15 Bits) Odd parity bit Par odd = 0 : the number of ones in the data word (D15:D1) is odd. Par odd = 1 : the number of ones in the data word (D15:D1) is even. An example of a complete write frame transmission is given in Figure 11 (gyroscope soft reset): Figure 11. Gyroscope soft reset frame Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 19/34 Rev. D SCC1300-D02 5.2.4 Gyro SPI Mixed Access Mode It is possible to mix the write and read access modes during one communication frame. Mixed access mode can be used, for example, to make an interleaved read of both angular rate and temperature data within the same SPI frame. Figure 12 shows an example of an interleaved read access: Figure 12. SPI read interleaving Each communication word in Figure 12 contains 16 SCK cycles. After the communication start condition (CSB falling edge), the master sends the address word ADR1 with the address of the Rate_X register (0x00), R/W = '0' (read access) and odd parity. All combined, ADR1 = 0x01. In parallel the SCC1300 sends out the status flags. During transmission of the next address word ADR2, the SCC1300 sends out the register value specified in ADR1 (Rate_X). On ADR2 the master performs another read access, now to the TEMP register (0x0A). The address word ADR2 will be 0x51 (TEMP register address 0x0A shifted to left by 3 bits and added odd parity bit; see Figure 9 for more details). To receive the register value of the second read access (Temperature), the master has to send an additional word to the MOSI (Zero Vector with Odd Parity). Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 20/34 Rev. D SCC1300-D02 5.3 Gyroscope ASIC Addressing Space The gyroscope ASIC has multiple register and EEPROM blocks. The EEPROM blocks used for holding calibration data are programmed via SPI during the manufacturing process. The user only needs to access the data register block at addresses 00h, 07h, 08h and 0Ah. The content of this register block is described below. Table 12. Gyroscope register address space Address hex Register Name 00h Rate_X 15:2 1 0 R 07h IC Identification 15:3 R/W Reserved, write all to 0 2 R/W Soft Reset Setting this bit to 1 to resets the logic core, see section 4.1.1 for more details. Reserved, write to 0 08h Status/Config 0Ah 5.3.1 Temp Bits Read/ Description Write R R Rate sensor output in two's complement format S_OK Flag 1 - Rate_X and Temp valid 0 - Rate_X and/or Temp invalid S_OK is generated from internal monitoring flags shown in the status register (08h). If any of the flags in register 08h [15:2] is 0, S_OK will be 0 Only if all flags in register 08h [15:2] are 1, S_OK will be 1 Odd Parity bit 1 R/W 0 15:10 R/W R 9 R 8:1 R Odd Parity bit Reserved Parity_OK This bit is set as soon as the SPI logic detects a wrong parity bit received from the C. The bit is automatically cleared during read access to this register. 1 - Parity check ok 0 - Parity error Reserved 0 R Odd Parity bit 15:2 R Temperature sensor output in two's complement format 1 R 0 R S_OK Flag 1 - Rate_X and Temp valid 0 - Rate_X and/or Temp invalid Odd Parity bit Angular Rate Output Register Angular rate data is presented in 14-bit, 2's complement format. Bits [1:0] do not contain angular rate data and they must be discarded. Rate_X bit weights are shown in below: Table 13. Gyroscope rate output bit weights [dps] (sensitivity 50 LSB/dps). D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 s 81.92 40.96 20.48 10.24 5.12 2.56 1.28 0.64 0.32 0.16 0.08 0.04 0.02 s_ok Par odd s = sign bit Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 21/34 Rev. D SCC1300-D02 5.3.1.1 Example of Rate Data Conversion According to the Gyroscope Register Map (Table 12) the bits 1:0 do not contain rate data and they must be discarded when converting rate register data to angular speed. For example: the Rate_X register (Address 0x00) data is 0xFF95. The bits 1:0 need to be discarded and as the rate is presented in 2's complement format, this can be done as an arithmetic shift right by 2 to handle the number sign correctly. So the actual data for rate calculation will be 0xFFE5 which equals -27 decimal. The sensitivity of the SCC1300-D02 is 50 LSB/(/s) (Table 2) so the rate in degrees per second will be: Rate_X[dps] = -27[LSB] / 50 LSB/dps = -0.54 dps 5.3.2 Gyro Temperature Output Register The gyroscope ASIC offers temperature information that has a linear response to temperature change. The temperature sensor reading does not reflect absolute ambient temperature. To use the temperature sensor as an absolute temperature sensor, the offset and sensitivity should be measured and calibrated at system level. Temperature data is presented in the Temp register (0x0A) in 14-bit, 2's complement format. The bits 1:0 do not contain temperature data and they must be discarded when making temperature calculations. The temperature register's typical output at +23 C is -1755 counts, and 1 C change in temperature typically corresponds to 65 counts. Temperature information is converted from counts to [C] as follows: Temp[ C ] = (Temp[LSB ] + 3250 ) / 65 , where Temp[LSB] is the TEMP register content in counts and Temp[C] is the equivalent temperature in Celsius. Temperature sensor offset calibration error at 25C: 15 C Temperature sensor sensitivity calibration error : 5% 5.3.2.1 Example of GYRO Temperature Conversion For example: the Temp register (0x0A) data is 0xEF5A. The bits 1:0 need to be discarded (Table 12) so the actual temperature data will be 0xFBD6m which equals -1066 decimal. Using the conversion formula above the actual temperature in C will be: Temp[C] = (-1066 + 3250) / 65 = 33.6 C Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 22/34 Rev. D SCC1300-D02 5.4 Accelerometer Interface This chapter describes the SCC1300 accelerometer sensor ASIC interface and how to use it. The accelerometer sensor ASIC SPI interface uses 8-bit addressing. 5.4.1 Accelerometer SPI Communication Overview Each communication frame contains 16 bits (two 8-bit bytes). The SPI frame format and transfer protocol for the accelerometer is presented in Figure 13 below. The accelerometer captures data on the SCK's rising edge (MOSI line) and data is propagated on the SCK's falling edge (MISO line). This is equal to SPI Mode 0 (CPOL = 0 and CPHA = 0). The SPI transmission is always started with the CSB falling edge and terminated with the CSB rising edge. Figure 13. SPI frame format for the accelerometer interface * * MOSI * * * * MISO * * * * * * * A5:A0 R/W aPAR DI7:DI0 Register address Read/Write selection, '0' = read, `1' = write Odd parity for bits A5:A0, R/W Input data for data write Bit 1 Not defined FRME FRaMe Error indication (from previous frame) Bit 3-5 status bits * PORST Power On Reset Status * ST Self Test error * SAT Output SATuration indicator Bit 6 Fixed bit, always `0' Bit 7 Fixed bit, always `1' dPAR Odd parity for output data (DO7:DO0) DO7:DO0 Output data The first 8 bits in the MOSI line contain info about the operation (read/write) and the register address being accessed. The first 6 bits form an address field for the selected operation, which is defined by bit 7 (`0' = read `1' = write) and is followed by an odd parity bit (aPAR) for the address. The following 8 bits in the MOSI line contain data for the write operation and are ignored in case of a read operation. The first bits in the MISO line are the Frame Error bit of the previous frame (FRME), the Power On Reset STatus bit (PORST), the Self-Test status bit (ST), the Saturation status bit (SAT), the fixed zero bit, the fixed one bit and the Odd Parity bit for output data (dPAR). Parity is calculated from data that is currently being sent. The following 8 bits contain data for a read operation. During a write operation, these data bits are the previous data bits of the addressed register. For write commands, data is written into the addressed register on the rising edge of the CSB. If the command frame is invalid, data will not be written into the register. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 23/34 Rev. D SCC1300-D02 For read commands, the output register is shifted out MSB first to the MISO output. An attempt to read a reserved register outputs data of 0x00. During the CSB high state between data transfers, the MISO line is kept in high-impedance state. 5.4.2 Accelerometer SPI Read Frame An example of X-axis acceleration read command is presented in Figure 14. 16-bit acceleration data is sent in two 8-bit data frames. Each frame contains a parity bit for data (odd parity). The acceleration data is presented in 2's complement format. When reading acceleration data, always read the MSB register before the LSB register because reading of MSB latches the LSB so the data in both registers will be from the same moment in time. The master gives the register address to be read via the MOSI line: '05' in hex format and th '000101' in binary format, register X_MSB. The 7 bit is set to '0' to indicate a read operation, and th the 8 bit is 1 for odd parity. The sensor replies to the requested operation by transferring the register content via the MISO line. After transferring the X_MSB register content, the master gives next register address to be read: '04' in hex format and '000100' in binary format, register X_LSB. The sensor replies to the requested operation by transferring the register content MSB bit first. Figure 14: Example of 16-bit acceleration data transfer from registers X_MSB, X_LSB (05h, 04h) DO15...DO0 bits are acceleration data (DO15 = MSB) and parity (dPAR) is odd parity for each 8bit data transmission. FRME is the possible frame error bit of previous frame, PORST is the reset bit, ST is the self-test status bit and SAT is the output saturation status bit. See section 5.5.2 for details about acceleration data conversion. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 24/34 Rev. D SCC1300-D02 5.4.3 Accelerometer SPI Write Frame An example of a CTRL register write command is presented in Figure 15. The master gives the register address to be written via the MOSI line: the CTRL register is '01' in th hex format and '000001' in binary format. The 7 bit is set to '1' to indicate a write operation, and th the 8 bit is 1 for odd parity. MISO data bits DO0 ... DO7 are the previous data bits of the CTRL register. Figure 15. Example of CTRL register write, set PORST = 0, Start STC (see Table 11) 5.4.4 Accelerometer Decremented Register Read Operation Figure 16 shows a decremented read operation where the content of four output registers is read by one SPI frame. After normal register addressing and reading of one register content, the MCU keeps the CSB line low and continues supplying SCK pulses. After every 8 SCK pulses, the output data address is decremented by one and the previous acceleration output register's content is shifted out without parity bits. The parity bit is calculated and transferred only for the first 8 bits of data. From the X_LSB register address the ASIC output address jumps to Z_MSB. Decremented reading is possible only for registers X_LSB ... Z_MSB. Accelerometer output registers are not updated during CSB low state, so the decremented read operation can be used to read all acceleration output registers' (Z_MSB ... X_LSB) content from the same moment of time. Decremented read is not recommended in fail-safe critical applications, because output data parity is only available for the first 8 bits of data. Figure 16. An Example of decremented read operation Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 25/34 Rev. D SCC1300-D02 5.4.5 5.4.5.1 Accelerometer SPI Error Conditioning (Self Diagnostics) FRME bit If the CSB is raised to '1' before sending all 16 SCKs in a frame, the frame is considered invalid. To support the decremented mode reading, the FRaMe Error is raised if the number of SCK pulses is not divisible by 8. The FRME bit is also set in case a wrong address parity (aPar) is sent. When an invalid frame is received, the last command is simply ignored and the register contents are left unchanged. The bit STATUS.FRME in the STATUS register (0x02) is set to indicate this error condition. During the next SPI frame this error bit is sent out as FRME status bit on the MISO line. The frame error condition will be reset only when a correct frame is received. 5.4.5.2 PORST bit The PORST bit is set if the chip is reset (HW reset by Power On Reset or supply on/off) or under voltage is detected. This bit is also set after power-up because the chip has been in a reset state. PORST can be set to zero (reset) by writing CTRL.PORST = 0. Software (SW) reset does not set the PORST bit. When CTRL.PORST bit is written to 0 via the SPI, there is a 300ns delay before the register value is set to zero. 5.4.5.3 ST bit The self-test frame status bit (ST) is set if STC or STS is alarmed or memory checksum test is not passed. * CASE 1: Checksum fails and the ST frame bit is set to 1. ST is set back to zero only when a new checksum calculation is passed. * 5.4.5.4 CASE 2: The ST frame bit is set to 1 because STC or STS is alarmed. In this case the ST frame bit can be cleared by reading the INT_STATUS register. SAT bit The saturation status (SAT) is set to 1 if any of the axis X,Y,Z output values is saturated. SAT can be cleared by reading the INT_STATUS register. This bit is kept high even after the failure condition is over if not cleared by reading the INT_STATUS register. 5.4.5.5 aPAR bit The aPAR is an odd parity bit of input address + R/W-bit. The master writes and the slave checks this bit. * If there is a parity error and R/W = '1', the write command is ignored and the FRME (frame error) bit is set in the STATUS register and in the SPI frame. The next correct SPI frame will zero this bit. * Murata Electronics Oy www.muratamems.fi If there is a parity error and R/W = '0', the read command is performed normally and the FRME bit is set in the STATUS register and in the SPI frame. The next correct SPI frame will zero this bit. Subject to changes Doc.Nr. 82113000 26/34 Rev. D SCC1300-D02 Table 14. Examples of correct address parity bit value Address A5 0 5.4.5.6 A4 0 A3 0 A2 0 A1 A0 0 0 R/W 0 aPAR 1 1 1 1 1 1 1 1 0 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0 0 dPAR bit The dPAR bit is an odd parity bit for 8-bit data that is currently sent in the frame. The master compares this bit to the received data. By using dPAR, at least 1-bit errors in data transmission can be detected. 5.4.5.7 Fixed bits Bits 6 and 7 in the MISO line are always fixed. Bit 6 should always be '0' and bit 7 always '1'. These bits can be used to verify that the MISO line is not permanently stuck to '1' or '0'. 5.4.5.8 SPI error effect on acceleration output data 1. Reset stage: When the component is in reset or under voltage state, the PORST bit in the SPI frame and the CTRL.PORST bit are set. In addition, all acceleration output register values are set to zero. 2. Saturation: When acceleration exceeds the sensor's measurement range, the output data is saturated to 2.27 g (-4096 / 4095 counts) 3. Self-diagnostic failure: The ST bit in the SPI frame is set when the memory diagnostic or signal path diagnostic functions fail. In addition, acceleration output data is forced to 0x7FFF if memory diagnostic fails or to 0xFFFF if signal path diagnostic functions (STC/STS) fail. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 27/34 Rev. D SCC1300-D02 5.5 Accelerometer ASIC Addressing Space The SCC1300 accelerometer ASIC register contents and bit definitions are described in detail in the following sections. Table 15. Accelerometer register address space Address hex 01h Register Name Bits Read/ Description Write R/W Please refer to Table 16 for CTRL register details. CTRL 7:0 02h STATUS 7:2 1 R R 0 R 03h RESET 7:0 R/W Reserved CSMERR: EEPROM checksum error 1 - Error, 0 - No error CSMERR also sets ST bit in SPI frame FRME: SPI frame error. Bit is reset when next correct SPI frame is received. FRME also sets FRME bit in SPI frame Writing 0C'hex, 05'hex, 0F'hex in this order resets component 04h X_LSB 7:0 R X-axis LSB data frame (Read always X_MSB prior to X_LSB) 05h X_MSB 7:0 R X-axis MSB data bits (Reading of this register latches X_LSB) 06h Y_LSB 7:0 R Y-axis LSB data frame (Read always Y_MSB prior to Y_LSB) 07h Y_MSB 7:0 R Y-axis MSB data bits (Reading of this register latches Y_LSB) 08h Z_LSB 7:0 R Z-axis LSB data frame (Read always Z_MSB prior to Z_LSB) 09h Z_MSB 7:0 R Z-axis MSB data bits (Reading of this register latches Z_LSB) 12h TEMP_LSB 7:0 R Data bits [7:0] of temperature sensor Always read TEMP_MSB prior to TEMP_LSB 13h TEMP_MSB 7:0 R Data bits [15:8] of temperature sensor Reading of this register latches TEMP_LSB 16h INT_STATUS 7 R Reserved 6 R SAT: Saturation status of output data 1 - Over range detected, at least one of XYZ axis is saturated and output data is not valid. 0 - Data in range SAT bit is also visible in SPI frame. This bit can be active after start-up, reset or PORST stage before signal path settles to final value. If accelerometer self diagnostics is used follow power-up sequence to acknowledge this bit (Table 11). 5 R STS: Status of gravitation based start-up self test 1 - Failure 0 - No failure STS also sets ST bit in SPI frame 4 R STC: Status of continuous self test 1 - Failure 0 - No failure STC also sets ST bit in SPI frame 3:0 R Reserved 27h ID 7:0 R Customer readable component identification number, value 27h Note: INT_STATUS: The bits in the interrupt status register and the corresponding SPI frame bits are cleared after this register has been read. Register reading is treated as interrupt acknowledgement signal. Bits in this register are kept active even if the failure condition is over until they are acknowledged by reading the register. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 28/34 Rev. D SCC1300-D02 5.5.1 Control Register (CTRL) Table 16. SCC1300 accelerometer CTRL control register (address 01h) bit level description 5.5.2 Bit Mode Name R/W RW Initial Value 0 0 7 6 Description 5 4 3 R/W R/W R/W 0 0 0 PDOW 2 R/W 0 MST 1 R/W 0 ST_CFG 0 R/W 0 PORST ST Reserved, write to 0 1 means reset state. Bit is set to 1 when the chip is reset by supply off control or under voltage control. Bit is set after supply off/on transition or startup. This bit can not be set by SPI but it can be reset by writing a 0 to it. This bit is also sent as Bit3 (PORST) of SPI output data frame on MISO. Write 1 to set accelerometer to power down mode Reserved, write to 0 Write 1 to enable continuous self test calculation (STC). This bit can not be set to 1 if CTRL.PDOW or CTRL.MST is already 1 or if CTRL.PDOW or CTRL.MST is being set by the current SPI command. Use INT_STATUS.STC and the ST bit in SPI frame for test result monitoring. Memory self-test function is activated when user sets this bit to 1. The bit is reset to 0 when self test is over. This bit can not be set to 1 if CTRL.PDOW is already 1 or if CTRL. PDOW is being set by the current SPI command. Test is done automatically during startup. Set other bits in CTRL register to zero with a separate SPI command before starting memory self-test with CTRL.MST command. Use STATUS.CSMERR and the ST bit in SPI frame for test result monitoring. During memory self test, SPI access is prevented for 85us. Write 1 to start gravitation based start-up self-test calculation (STS). This bit can not be set to 1 if CTRL.PDOW or CTRL.MST is already 1 or if CTRL.PDOW or CTRL.MST is being set by the current SPI command. STC and STS have same priority and they can be set and used simultaneously. This bit is set to 0 when test is over. Use INT_STATUS.STS and ST bit of SPI frame for test result monitoring. Reserved, write to 0 Acceleration output registers Acceleration data is presented in 14-bit, 2's complement format in registers X_LSB ... Z_MSB. At 0 g acceleration the output is ideally 0000h. Acceleration data bit weights are shown in Table 17: Table 17. Acceleration output bit weights [mg] (Sensitivity 1800 LSB/g). DOUT MSB bits(7:0) DOUT LSB bits(7:0) D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 s s s 1137.8 568.9 284.4 142.2 71.1 35.6 17.8 8.89 4.44 2.22 1.11 0.56 x s = sign bit 5.5.2.1 Example of acceleration data conversion For example, if X_MSB = 0xFA and X_LSB = 0xEC, the combined X-axis acceleration data is 0xFAEC. Acceleration output bit 0 is not used and needs to be discarded (Table 17). As the data is presented in 2's complement format, the number sign needs to be handled correctly. This can be done as an arithmetic shift right by 1. So the actual data for acceleration calculation will be 0xFD76 which equals -650 decimal. The sensitivity of the SCC1300-D02 is 1800 LSB/g (Table 2) so the acceleration in g's will be: X_acc[g] = -650[LSB] / 1800 LSB/g = -0.361 g Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 29/34 Rev. D SCC1300-D02 5.5.3 Accelerometer Temperature Output Registers Offset of the accelerometer temperature data is factory calibrated, but sensitivity varies from part to part. Temperature data is presented in 13-bit unsigned format and uses 13 bits (13:1) of TEMP_MSB/TEMP_LSB registers. Always read TEMP_MSB prior to TEMP_LSB because reading the MSB register latches the LSB register. 5.5.3.1 Example of accelerometer temperature conversion Table 18. Bit level description for the accelerometer temperature registers TEMP MSB bits(7:0) TEMP LSB bits(7:0) D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 x x T12 T11 T10 T9 T8 T7 T6 T5 T4 T3 T2 T1 T0 x x = not used The temperature registers' typical output at +23 C is 4096 counts and a 1 C change in temperature typically corresponds to 25.6 counts. Temperature information is converted from counts to [C] as follows: Temp[C ] = (23 10 ) + TempLSB - 4096 k where Temp[C] is temperature in Celsius and Temp LSB is temperature from TEMP_MSB and TEMP_LSB registers in decimal format, bits(T12:0). k is the temperature slope factor specified as k Murata Electronics Oy www.muratamems.fi Min 22.4 Typ 25.6 Max 28.8 Subject to changes Doc.Nr. 82113000 Unit o LSB/ C 30/34 Rev. D SCC1300-D02 6 Application Information 6.1 Application Circuitry and External Component Characteristics Recommended circuit diagram is presented in Figure 17. The component characteristics are presented in Table 19. Figure 17. Recommended circuit diagram of the SCC1300. The optional filtering recommendation for a better PSRR (Power Supply Rejection Ratio) is presented in Figure 18. Please note that PSSR filtering is optional and not required if the 3.3V power supply is already stable enough. RC filtering (R1 & C8 without L2) could also be sufficient for most cases. Figure 18. Optional filtering recommendation to improve PSRR if required. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 31/34 Rev. D SCC1300-D02 6.1.1 Separate Analog and Digital Ground Layers with Long Power Supply Lines If power supply routings/cablings are long, separate ground cabling, routing and layers for analog and digital supply voltages should be used to avoid excessive power supply ripple. In the recommended circuit diagram (Figure 17) and layout example (Figure 20), joint ground is used as it is the simplest solution and is adequate as long as the supply voltage lines are not long (when connecting the SCC1300 directly to C on the same PCB). Table 19. SCC1300 external components Component C1, C2, C3, C4, C5 C7 L1 C6 Optional for better PSRR: R1 C8 L2 Murata Electronics Oy www.muratamems.fi Parameter Capacitance ESR @ 1 MHz Voltage rating Capacitance ESR @ 1 MHz Voltage rating Inductance ESR L=47 H Voltage rating Capacitance ESR @ 1 MHz Resistance Capacitance Impedance Subject to changes Doc.Nr. 82113000 Min 70 Typ 100 Max 130 100 7 376 470 564 100 30 37 47 57 5 30 0.7 1 1.3 100 10 4.7 1k Unit nF m V nF m V H V F m F 32/34 Rev. D SCC1300-D02 6.2 Boost Regulator and Power Supply Decoupling in Layout Recommended layout for DVDD_G/LHV pin decoupling is shown in Figure 19. Figure 19. Layout recommendations for DVDD_G/LHV pin decoupling 6.2.1 Layout Example Figure 20. Example layout for the SCC1300 Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 33/34 Rev. D SCC1300-D02 6.2.2 Thermal Connection The component has heat sink pins to transfer internally generated heat from the package to ambient. Thermal resistance to ambient should be low enough not to self heat the device. If the internal junction temperature gets too high compared to ambient, this may lead to out of specification behavior. Table 20. Thermal resistance Component Thermal resistance JA 6.3 Parameter Total thermal resistance from junction to ambient Min Typ Max 50 Unit C/W Assembly Instructions Usage of PCB coating materials may effect component performance. The coating material and coating process used should be validated. For additional assembly related details please refer to "Technical Note 82" for assembly instructions. Murata Electronics Oy www.muratamems.fi Subject to changes Doc.Nr. 82113000 34/34 Rev. D