MMA7456LT Freescale Semiconductor, MMA7456LT Datasheet
MMA7456LT
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MMA7456LT Summary of contents
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... Pedometer • Motion Sensing, Event Recorder ORDERING INFORMATION Part Number Temperature Range MMA7456LT –40 to +85°C MMA7456LR1 –40 to +85°C MMA7456LR2 –40 to +85°C This document contains certain information on a new product. Specifications and information herein are subject to change without notice. ...
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... Clearing the Interrupt Pins: Register $17 .....................................................................................................................15 Detecting Interrupts ......................................................................................................................................................16 Digital Interface ........................................................................................................................................................................... Slave Interface .......................................................................................................................................................16 SPI Slave Interface ......................................................................................................................................................18 BASIC CONNECTIONS .............................................................................................................................................................19 Pin Descriptions ...........................................................................................................................................................19 Recommended PCB Layout for Interfacing Accelerometer to Microcontroller .............................................................19 Register Definitions ....................................................................................................................................................................21 Soldering and Mounting Guidelines for the LGA Accelerometer Sensor Board ............................................................29 Sensors Freescale Semiconductor MMA7456L 2 ...
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... Incorrect PCB Top Metal Pattern Under Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Correct PCB Top Metal Pattern Under Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Recommended PCB Land Pad, Solder Mask, and Signal Trace Near Package Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Stencil Design Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Temperature Coefficient of Offset (TCO) and Temperature Coefficient of Sensitivity (TCS) Distribution Charts . . . . . . . . . . . 32 Current Distribution Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Sensors Freescale Semiconductor MMA7456L 3 ...
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... Configuring the Interrupt settings using Register $18 with INTREG[1:0] bits .............................................................................26 $1A: Level Detection Threshold Limit Value (Read/Write) .........................................................................................................27 $1B: Pulse Detection Threshold Limit Value (Read/Write) .........................................................................................................27 $1C: Pulse Duration Value (Read/Write) ....................................................................................................................................27 $1D: Latency Time Value (Read/Write) ......................................................................................................................................27 $1E: Time Window for 2nd Pulse Value (Read/Write) ................................................................................................................27 Acceleration vs. Output (8-bit data) ............................................................................................................................................28 Sensors Freescale Semiconductor MMA7456L 4 ...
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... V on pin 4 DD <$1C = 0001 1100 > bit 0 is GND on pin 4. If the pin is programmed it cannot be left NC. Figure 2. Simplified Accelerometer Functional Block Diagram Sensors Freescale Semiconductor Description C Enable (1) Pin Status Input Input Input Input ...
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... ESD. A charge of over 2000 volts can accumulate on the human body or associated test equipment. A charge of this magnitude can alter the performance or cause failure of the chip. When handling the accelerometer, proper ESD precautions should be followed to avoid exposing the device to discharges which may be detrimental to its performance. Sensors Freescale Semiconductor Symbol Value g ...
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... Wait Time for I C/SPI ready after power on Turn On Response Time (Standby to Normal Mode) Turn Off Response Time (Normal to Standby Mode) Self-Test Response Time Sensing Element Resonant Frequency XY Z Nonlinearity (2 g range) Cross Axis Sensitivity Sensors Freescale Semiconductor < 3.6 V, Acceleration = 0g, Loaded output. DD Symbol DD_IO DV ...
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... The ASIC uses switched capacitor techniques to measure the g-cell capacitors and extract the acceleration data from the differ- ence between the two capacitors. The ASIC also signal conditions and filters (switched capacitor) the signal, providing a digital output that is proportional to acceleration. Figure 3. Simplified Transducer Physical Model Sensors Freescale Semiconductor Symbol Min 0 0.5 — ...
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... By default all three axes are enabled. X and/or Y and/or Z can be disabled. There is a choice between detecting an absolute signal or a positive or negative only signal on the enabled axes. There is also a choice between doing a detection for motion where > Threshold vs. doing a detection for freefall where X & Y & Z < Threshold. Sensors Freescale Semiconductor ...
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... Assigning, Clearing & Detecting Interrupts Source Register $0A LDTH[7] LDTH[6] LDTH[ LDTH[7:0]: Level detection threshold value. If THOPT bit in Detection Control Register is “0” unsigned 7 bits value and LDTH[7] should be “0”. If THOPT bit is “1” signed 8 bits value. Sensors Freescale Semiconductor Interrupts YDA XDA INTREG[ ...
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... Reg $18 THOPT=1; Reg 19 LDPL=1, Set Threshold to 0.5g, which is 7 counts (16 counts/g). Set register $1A LDTH = $07 CASE 4: Freefall Detection Absolute: ||X|| <Threshold AND ||Y|| < Threshold AND ||Z||< Threshold Reg $18 THOPT=0; Reg 19 LDPL=1, Set Threshold to +/-0.5g, which is 7 counts (16 counts/g). Set register $1A LDTH = $07. Sensors Freescale Semiconductor $07 ...
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... The Pulse threshold must be set in Register $1B and the pulse duration time window must also be set using Register $1C. The pulse must be detected before the time window closes for the interrupt to trigger. $1B: Pulse Detection Threshold Limit Value (Read/Write PDTH[7] PDTH[6] PDTH[ $1C: Pulse Duration Value (Read/Write PD[7] PD[6] PD[ Sensors Freescale Semiconductor section YDA XDA INTREG[ DRVO ...
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... Pulse Detection Threshold Limit Value (Read/Write PDTH[7] PDTH[6] PDTH[ $1D: Latency Time Value (Read/Write LT[7] LT[6] LT[ Sensors Freescale Semiconductor Pulse Detection Time duration Time *Note there 1.6ms delay on the interrupt signal Time nd pulse $ indicating single pulse Figure 4. Single Pulse Detection PDTH[4] PDTH[3] PDTH[ ...
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... Register $18, discussed in the Assigning, Clearing & Detecting Interrupts monitored by the detection source register $0A. G Pulse Detection Time Window G th Detection Source Register INT Double Pulse Detection ($19 PDPL=0 indicating motion detection) Time Window for 2 Sensors Freescale Semiconductor PDTH[4] PDTH[3] PDTH[ PD[4] ...
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... After interrupt has triggered due to a detection, the interrupt pin (INT1 or INT2) need to be cleared by writing a logic 1. Then the interrupt pin should be enabled to trigger the next detection by setting logic 0. This example is to show how to reset the interrupt flags void ClearIntLatch(void) { IIC_ByteWrite(INTRST, 0x03); IIC_ByteWrite(INTRST, 0x00); } Sensors Freescale Semiconductor YDA XDA INTREG[ “ ...
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... MMA7456L acknowledgment (AK) is received until a NACK is received from the Master followed by a stop condition (SP) signalling an end of transmission. See Figure 8. Sensors Freescale Semiconductor PDX PDY ...
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... The MMA7456L automatically increments the received register address commands after a write command is received. Therefore, after following the steps of a single byte write, multiple bytes of data can be written to sequential registers after each MMA7456L acknowledgment (ACK) is received. See Figure 10. Multiple Byte Writes - The Master (MCU) is writing to multiple sequential registers of the MMA7456L Sensors Freescale Semiconductor Figure 10. MMA7456L 17 ...
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... Figure 11. SPI Timing Diagram for 8-Bit Register Read (4 Wire Mode) Figure 12. SPI Timing Diagram for 8-Bit Register Read (3 Wire Mode) Figure 13. SPI Timing Diagram for 8-Bit Register Write (3 Wire Mode) Sensors Freescale Semiconductor Figure 11 and Figure 13 for the timing diagram for an 8-bit data write. ...
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... GND N/C IADDR0 GND AVDD Figure 14. Pinout Description Recommended PCB Layout for Interfacing Accelerometer to Microcontroller AV Vdd Vdd DD 10uF 10uF 0.1uF 0.1uF GND GND Sensors Freescale Semiconductor Table 8. Pin Descriptions Pin # Pin Name 1 DVDD_IO 2 GND 3 N/C 4 IADDR0 SDA/SDI/SDO 5 GND SDO 6 AVDD N/C ...
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... Any external power supply switching frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency (sampling frequency). This will prevent aliasing errors. 6. Physical distance of the two GND pins (Pin 2 and Pin 5) tied together should be at the shortest distance. Sensors Freescale Semiconductor ...
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... Output Value X LSB (Read only XOUT [7] XOUT [6] XOUT [ Signed byte data (2’s complement 10’h000 Reading low byte XOUTL latches high byte XOUTH to allow 10-bit reads. XOUTH should be read directly following XOUTL read. Sensors Freescale Semiconductor Bit 7 Bit 6 Bit 5 XOUT[7] XOUT[6] XOUT[ YOUT[7] YOUT[6] YOUT[5] -- ...
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... Output Value X MSB (Read only $06: 8bits Output Value X (Read only XOUT[7] XOUT [6] XOUT [ Signed byte data (2’s complement 8’h00 $07: 8bits Output Value Y (Read only YOUT[7] YOUT [6] YOUT [ Signed byte data (2’s complement 8’h00 Sensors Freescale Semiconductor YOUT [4] YOUT [3] YOUT [ ZOUT [4] ZOUT [3] ...
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... I2CDIS and SPI are available disabled. 2 DVAD[6:0 device address $0E: User Information (Read Only: Optional UI[7] UI[6] UI[5] 0/OTP 0/OTP 0/OTP UI2[7:0]: User information Sensors Freescale Semiconductor ZOUT [4] ZOUT [3] ZOUT [ PERR PERR 1: Parity error is detected in trim data. Then, self-test is dis- abled 0: Parity error is not detected in trim data ...
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... Signed byte data (2’s complement): User level offset trim value for Z-axis Bit ZOFF[7] ZOFF[6] Weight* 64 LSB 32 LSB *Bit weight is for 2g 8bit data output. Typical value for reference only. Variation is specified in “Electrical Characteristics” section. Sensors Freescale Semiconductor [4] ID [3] ID [2] 0/OTP 0/OTP ...
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... MODE [1:0] 00: Standby Mode 01: Measurement Mode 10: Level Detection Mode 11: Pulse Detection Mode Table 11. Configuring the Mode using Register $16 with MODE[1:0] bits MODE [1:0] Sensors Freescale Semiconductor ZOFF[10 ZOFF[10] ZOFF[9] ...
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... LDPL 0: Level detection polarity is positive and detecting condition axes. 1: Level detection polarity is negative detecting condition is AND 3 axes. PDPL 0: Pulse detection polarity is positive and detecting condition axes. 1: Pulse detection polarity is negative and detecting condition is AND 3 axes. Sensors Freescale Semiconductor CLR_INT2 1: Clear “INT2” and LDX/LDY/LDZ or PDX/PDY/PDZ bits in Detection Source Register ($0A) depending on Control1($18) INTREG[1:0] setting ...
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... Min: LT[7:0] = 8’h01 = 1 ms Max: LT[7:0] = 8’hFF = 255 ms 1 LSB = 1 ms $1E: Time Window for 2nd Pulse Value (Read/Write TW[7] TW[6] TW[ Min: TW[7:0] = 8’h01 = 1 ms (Single pulse detection) Max: TW[7:0] = 8’hFF = 255 ms 1 LSB = 1 ms Sensors Freescale Semiconductor LDTH[4] LDTH[3] LDTH[ PDTH[4] PDTH[3] PDTH[2] 0 ...
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... OUT $00 OUT $00 14 OUT OUT * When positioned as shown, the Earth’s gravity will result in a positive 1g output. Figure 17. Sensing Direction and Output Response at 2g Mode Table 13. Acceleration vs. Output (8-bit data) 2g Mode 4g Mode 8g Mode Sensors Freescale Semiconductor Top View $00 @ + -1g = $C1 OUT ...
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... Array (LGA) package platform. This section describes suggested methods of soldering these devices to the PC board for con- sumer applications. Figure 18 shows the recommended PCB land pattern for the package. Figure 18. Recommended PCB Land Pattern for the LGA Package Sensors Freescale Semiconductor MMA7456L 29 ...
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... Pad Dimension by Package 0.5 mm 0.8 mm Cu: 0.9 x 0.6 mm sq. Figure 21. Recommended PCB Land Pad, Solder Mask, and Signal Trace Near Package Design Sensors Freescale Semiconductor Figure 20. LGA package w/ solder PCB top metal layer Example of 2 layer PCB Figure 20. Correct PCB Top Metal Pattern Under Package ...
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... Freescale LGA sensors are compliant with Restrictions on Hazardous Substances (RoHS), having halide free molding compound (green) and lead-free terminations. These terminations are compatible with tin-lead (Sn-Pb) as well as tin-silver-copper (Sn-Ag- Cu) solder paste soldering processes. Reflow profiles applicable to those processes can be used successfully for soldering the devices. Sensors Freescale Semiconductor 10x0.8mm 14x0.575mm Figure 22. Stencil Design Guidelines Figure 21 ...
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... LSL -3 -2 Yoff_mg/degree C_-40to85 LSL -3 -2 Zoff_mg/degreeC_-40to85 LSL -3 -2 Figure 23. MMA7456L Temperature Coefficient of Offset (TCO) and Temperature Coefficient of Sensitivity (TCS) Distribution Charts Figure 24. MMA7456L Current Distribution Charts Sensors Freescale Semiconductor Xsens_%/DegreeC_-40to85 LSL Targ et USL - -0.02 -0.01 Ysens_%/DegreeC_-40to85 T arg et USL ...
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... Sensors Freescale Semiconductor PACKAGE DIMENSIONS CASE 1977-01 ISSUE A 14-LEAD LGA MMA7456L 33 ...
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... Sensors Freescale Semiconductor PACKAGE DIMENSIONS CASE 1977-01 ISSUE A 14-LEAD LGA MMA7456L 34 ...
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... Freescale Semiconductor product could create a situation where personal injury or death may occur. Should Buyer ...