Datasheet

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Document Number: MMA7660FC

Rev 8, 03/2012

Freescale Semiconductor

Data Sheet: Technical Data

An Energy Efficient Solution by Freescale

3-Axis Orientation/Motion

Detection Sensor

The MMA7660FC is a ±1.5 g 3-Axis Accelerometer with Digital Output

C). It is a very low power, low profile capacitive MEMS sensor featuring a

low pass filter, compensation for 0g offset and gain errors, and conversion to

6-bit digital values at a user configurable samples per second. The device can

be used for sensor data changes, product orientation, and gesture detection

through an interrupt pin (INT

). The device is housed in a small 3mm x 3mm x

0.9mm DFN package.

Features

• Digital Output (I

• 3mm x 3mm x 0.9mm DFN Package

• Low Power Current Consumption: Off Mode: 0.4 µA,

Standby Mode: 2 µA, Active Mode: 47 µA at 1 ODR

• Configurable Samples per Second from 1 to 120 samples a second.

• Low Voltage Operation:

– Analog Voltage: 2.4 V - 3.6 V

– Digital Voltage: 1.71 V - 3.6 V

• Auto-Wake/Sleep Feature for Low Power Consumption

• Tilt Orientation Detection for Portrait/Landscape Capability

• Gesture Detection Including Shake Detection and Tap Detection

• Robust Design, High Shocks Survivability (10,000 g)

• RoHS Compliant

• Halogen Free

• Environmentally Preferred Product

• Low Cost

Typical Applications

• Mobile Phone/ PMP/PDA: Orientation Detection (Portrait/Landscape),

Image Stability, Text Scroll, Motion Dialing, Tap to Mute

• Laptop PC: Anti-Theft

• Gaming: Motion Detection, Auto-Wake/Sleep For Low Power

Consumption

• Digital Still Camera: Image Stability

ORDERING INFORMATION

Part Number Temperature Range Package Shipping

MMA7660FCT

–40 to +85°C DFN-10 Tray

MMA7660FCR1

–40 to +85°C DFN-10 7” Tape & Reel

N/C

DVDD

DVSS

SDA

SCL

RESERVED

N/C

AVDD

AVSS

INT

Figure 1. Pin Connections

RESERVED

10 LEAD

DFN

CASE 2002-03

MMA7660FC

MMA7660FC: XYZ-AXIS

ACCELEROMETER

±1.5 g

Bottom View

Top View

Summary of content (35 pages)

PAGE 1
Document Number: MMA7660FC Rev 8, 03/2012 Freescale Semiconductor Data Sheet: Technical Data An Energy Efficient Solution by Freescale 3-Axis Orientation/Motion Detection Sensor MMA7660FC The MMA7660FC is a ±1.5 g 3-Axis Accelerometer with Digital Output (I2C). It is a very low power, low profile capacitive MEMS sensor featuring a low pass filter, compensation for 0g offset and gain errors, and conversion to 6-bit digital values at a user configurable samples per second.
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Contents DEFINITIONS ............................................................................................................................................................................... 5 ELECTRO STATIC DISCHARGE (ESD) ...................................................................................................................................... 7 PRINCIPLE OF OPERATION ..........................................................................................................................
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List of Tables Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 ESD And Latch-up Protection Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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List of Figures I2C Connection to MCU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Simplified Accelerometer Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Simplified Transducer Physical Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Definitions Auto-Wake: Sleep Mode (uses AMSR sample rate in SR [0x08] register) Auto-Sleep: Run Mode (uses AWSR sample rate in SR [0x08] register) PMP: Portable Media Player PDA: Personal Digital Assistant DFN: Dual Flat No Lead ESD: Electro Static Discharge ODR: Output Data Rate MEMS: Microelectromechanical Systems MMA7660FC Sensors Freescale Semiconductor 5
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Table 1. Pin Description Top View RESERVED N/C AVDD Pin # Pin Name 1 RESERVED 1 10 RESERVED 2 N/C 2 9 DVDD 3 4 8 3 DVSS AVSS 4 7 SDA INT 5 6 SCL Figure 1.
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AVDD DVDD INTERNAL OSC VSS CLOCK GEN X-axis Transducer Y-axis Transducer MUX C-to-V CONVERTER AMP ADC SDA I2 C SCL Z-axis Transducer OFFSET TRIM GAIN TRIM INT CONTROL LOGIC Figure 3. Simplified Accelerometer Functional Block Diagram Table 2. Maximum Ratings (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.) Rating Symbol Value Unit Maximum Acceleration (all axes, 100 μs) gmax 10,000 g Analog Supply Voltage AVDD -0.3 to +3.
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Table 4. Operating Characteristics Unless otherwise noted: -40°C < TA < 85°C, 2.4 V < AVDD < 3.6 V, 1.71 V < DVDD < 3.6 V, Acceleration = 0g Typical values are at AVDD = 2.8 V, DVDD = 2.8 V, TA = +25°C Characteristics Symbol Min Typ Max Unit Standby/Operation Mode AVDD 2.4 2.8 3.6 V Enable Bus Modeon Mode AVDD Analog Supply Voltage 0 V Digital I/O Pins Supply Voltage Standby/Operation Mode DVDD_IO 1.71 2.8 AVDD V Enable Bus Modeon Mode DVDD_IO 1.71 1.8 3.
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PRINCIPLE OF OPERATION The Freescale Accelerometer consists of a MEMS capacitive sensing g-cell and a signal conditioning ASIC contained in a single package. The sensing element is sealed hermetically at the wafer level using a bulk micro machined cap wafer. The g-cell is a mechanical structure formed from semiconductor materials (polysilicon) using masking and etching processes. The sensor can be modeled as a movable beam that moves between two mechanically fixed beams (Figure 4).
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MODES OF OPERATION The sensor has three power modes: Off Mode, Standby Mode, and Active Mode to offer the customer different power consumption options. The sensor is only capable of running in one of these modes at a time. The Off Mode offers the lowest power consumption, approximately 0.4 µA and can only be reached by powering down the analog supply. See Figure 5. In this mode, there is no analog supply and all I2C activity is ignored. The Standby Mode is ideal for battery operated products.
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CONFIGURABLE SAMPLES PER SECONDS AND INTERRUPT SETTINGS The device can be configured into 8 different samples per seconds including: 1 sample/second, 2 samples/second, 4 samples/second, 8 samples/second, 16 samples/second, 32 samples/second, 64 samples/second, and 120 samples/second, The user can specify the samples per second for their particular application, deciding on the trade off between power consumption and number of samples, this can be configured in the SR (0x08) register.
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Orientation Detection Orientation Detection Logic MMA7660FC gives the customer the capability to do orientation detection for such applications as Portrait/Landscape in Mobile Phone/PDA/ PMP. The tilt orientation of the device is in 3 dimensions and is identified in its last known static position. This enables a product to set its display orientation appropriately to either portrait/landscape mode, or to turn off the display if the product is placed upside down.
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Tap Detection The MMA7660FC also includes a Tap Detection feature that can be used for a number of different customer applications such as button replacement. For example, a single tap can stop a song from playing and a double tap can play a song. This function detects a fast transition that exceeds a user-defined threshold (PDET (0x09) register) for a set duration (PD (0x0A) register).
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REGISTER DEFINITIONS Table 9.
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$03: Tilt Status (Read only) TILT D7 D6 D5 D4 D3 D2 D1 D0 Shake Alert Tap PoLa[2] PoLa[1] PoLa[0] BaFro[1] BaFro[0] 0 0 0 0 0 0 0 0 BaFro[1:0] Tap 1: Equipment has detected a tap 0: Equipment has not detected a tap 00:Unknown condition of front or back 01: Front: Equipment is lying on its front 10: Back: Equipment is lying on its back PoLa[2:0] 000: Unknown condition of up or down or left or right 001: Left: Equipment is in landscape mode to the left 010: Right: Equipment is in lan
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$06: Interrupt Setup Register INTSU D7 D6 D5 D4 D3 D2 D1 D0 SHINTX SHINTY SHINTZ GINT ASINT PDINT PLINT FBINT 0 0 0 0 0 0 0 0 FBINT 0: Front/Back position change does not cause an interrupt 1: Front/Back position change causes an interrupt PLINT 0: Up/Down/Right/Left position change does not cause an interrupt 1: Up/Down/Right/Left position change causes an interrupt PDINT 0: Successful tap detection does not cause an interrupt 1: Successful tap detection causes an interrupt ASINT 0:
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$07: Mode Register (Read/Write) MODE D7 D6 D5 D4 D3 D2 D1 D0 IAH IPP SCPS ASE AWE TON - MODE 0 0 0 0 0 0 0 0 NOTE: Writing to the Mode register resets sleep timing, and clears the XOUT, YOUT, ZOUT, TILT registers.Reading to the Mode register resets sleep timing. NOTE: The device must be placed in Standby Mode to change the value of the registers. Table 10.
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Table 11. ASE/AWE Conditions Condition Auto-Wake (Sleep Mode) Auto-Sleep (Run Mode) AWE = 0, ASE = 0 X AWE = 1, ASE = 0 X AWE = 0, ASE = 1 X X AWE = 1, ASE = 1 X X NOTE: If interrupts are enabled, interrupts will behave normally in all conditions stated in Table 11. Table 12. Sleep Counter Timeout Ranges SCPS = 0 SCPS = 1 AMSR Minimum Range (20) Maximum Range (28) Minimum Range (20) Maximum Range (28) 1 SPS 1s 256 s 16 s 4096 s 2 SPS 0.5 s 128 s 8s 2048 s 4 SPS 0.
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AMSR[2:0] NAME 000 AMPD Tap Detection Mode and 120 Samples/Second Active and Auto-Sleep Mode Tap Detection Sampling Rate: The device takes readings continually at a rate of nominally 3846 g-cell measurements a second. It then filters these high speed measurements by maintaining continuous rolling averages of the current and last g-cell measurements. The averages are updated every 260 µs to track fast moving accelerations.
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AWSR[1:0] 00 NAME AW32 01 AW16 10 AW8 11 AW1 FILT[2:0] 000 001 010 011 100 101 110 111 DESCRIPTION 32 Samples/Second Auto-Wake Mode For portrait/landscape detection: The device takes and averages 32 g-cell measurements every 31.25 ms in Auto-Wake. The update rate is 32 samples per second. These measurements update the XOUT (0x00), YOUT (0x01), and ZOUT (0x02) registers also.
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$09: Tap/Pulse Detection Register (Read/Write) PDET D7 D6 D5 D4 D3 D2 D1 D0 ZDA YDA XDA PDTH[4] PDTH[3] PDTH[2] PDTH[1] PDTH[0] 0 0 0 0 0 0 0 0 NOTE: If XDA = YDA = ZDA = 0, samples per second is 120 samples/second, and Auto-Wake/Sleep feature is enabled, the tap interrupt will reset the sleep counter. PDTH[4:0] 00000 00001 00010 00011 ... 11101 11110 11111 DESCRIPTION Tap detection threshold is ±1 count Tap detection threshold is ±2 counts Tap detection threshold is ±3 counts ...
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SERIAL INTERFACE Serial-Addressing MMA7660FC operates as a slave that sends and receives data through an I2C 2-wire interface. The interface uses a Serial Data Line (SDA) and a Serial Clock Line (SCL) to achieve bi-directional communication between master(s) and slave(s). A master (typically a microcontroller) initiates all data transfers to and from the device, and generates the SCL clock that synchronizes the data transfer.
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Acknowledge The acknowledge bit is a clocked 9th bit, shown in Figure 10, which the recipient uses to handshake a receipt of each byte of data. Thus each byte transferred effectively requires 9-bits. The master generates the 9th clock tap, and the recipient pulls down SDA during the acknowledge clock tap, such that the SDA line is stable low during the high period of the clock tap. When the master is transmitting to MMA7660FC, it generates the acknowledge bit because it is the recipient.
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If multiple data bytes are transmitted before a STOP condition is detected, these bytes are generally stored in subsequent MMA7660FC internal registers because the register address generally auto-increments. Master ST Device Address [6:0] W Register Address [6:0] AK Slave Data [7:0] AK Data [7:0] SP AK AK Figure 13.
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APPENDIX A – PACKAGE REQUIREMENTS FOR MMA7660FC Minimum Recommended Footprint for Surface Mounted Applications Surface mount board layout is a critical portion of the total design. The footprint for the surface mount packages must be the correct size to ensure proper solder connection interface between the board and the package. With the correct footprint, the packages will self-align when subjected to a solder reflow process.
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Figure 16. Package Footprint, PCB Land Pattern, and Stencil Design Figure 17. PCB Land Pattern Detail MMA7660FC Sensors Freescale Semiconductor, Inc.
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APPENDIX B - SENSING DIRECTION Top View Direction of Earth’s Gravity XOUT @ 0g YOUT @ 0g ZOUT @ +1g XOUT @ -1g YOUT @ 0g ZOUT @ 0g Side View XOUT @ 0g YOUT @ -1g ZOUT @ 0g XOUT @ 0g YOUT @ +1g ZOUT @ 0g XOUT @ 0g YOUT @ 0g ZOUT @ -1g XOUT @ +1g YOUT @ 0g ZOUT @ 0g Figure 18. Product Orientation on Perpendicular Axis +Z -Z +Y -Y -X +X -X +X +Y -Y -Z +Z Figure 19. Product Orientations Showing Direction for Each Axis in Composite MMA7660FC 27 Sensors Freescale Semiconductor, Inc.
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APPENDIX C - MMA7660FC ACQUISITION CODE TABLE Binary 2's Comp g value Angle X or Y Angle Z 0 0 0 0.000g 0.00° 90.00° 1 1 1 0.047g 2.69° 87.31° 2 10 2 0.094g 5.38° 84.62° 3 11 3 0.141g 8.08° 81.92° 4 100 4 0.188g 10.81° 79.19° 5 101 5 0.234g 13.55° 76.45° 6 110 6 0.281g 16.33° 73.67° 7 111 7 0.328g 19.16° 70.84° 8 1000 8 0.375g 22.02° 67.98° 9 1001 9 0.422g 24.95° 65.05° 10 1010 10 0.469g 27.95° 62.05° 11 1011 11 0.516g 31.04° 58.
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APPENDIX C - MMA7660FC ACQUISITION CODE TABLE, continued 49 110001 -15 -0.703g -44.68° -45.32° 48 110000 -16 -0.750g -48.59° -41.41° 47 101111 -17 -0.797g -52.83° -37.17° 46 101110 -18 -0.844g -57.54° -32.46° 45 101101 -19 -0.891g -62.95° -27.05° 44 101100 -20 -0.938g -69.64° -20.36° 43 101011 -21 -0.984g -79.86° -10.14° 42 101010 -22 -1.031g 41 101001 -23 -1.078g 40 101000 -24 -1.125g 39 100111 -25 -1.172g 38 100110 -26 -1.
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APPENDIX D - I2C AC CHARACTERISTICS This section includes information about I2C AC Characteristics. Table 1. I2C AC Characteristics (Typical Operating Circuit, VDD = 1.71 V to 2.75 V, TA = TMIN to TMAX, unless otherwise noted. Typical current values are at VDD = 1.8 V, TA = +25°C.) Parameter Symbol Min Typ Max Units 400 kHz Serial Clock Frequency(1) fSCL Bus Free Time Between a STOP and a START Condition(2) tBUF 1.3 µs Hold Time, (Repeated) START Condition(2) tHD, STA 0.
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PACKAGE DIMENSIONS MMA7660FC 31 Sensors Freescale Semiconductor, Inc.
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PACKAGE DIMENSIONS MMA7660FC Sensors Freescale Semiconductor, Inc.
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PACKAGE DIMENSIONS MMA7660FC 33 Sensors Freescale Semiconductor, Inc.
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Table 2. Revision History Revision number Revision date 9 03/2012 Description of changes • Changed pin 10 from N/C to RESERVED on page 1, Figure 1, Figure 2 and Table 1: Pin description. MMA7660FC Sensors Freescale Semiconductor, Inc.
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How to Reach Us: Home Page: www.freescale.com Web Support: http://www.freescale.com/support USA/Europe or Locations Not Listed: Freescale Semiconductor, Inc. Technical Information Center, EL516 2100 East Elliot Road Tempe, Arizona 85284 1-800-521-6274 or +1-480-768-2130 www.freescale.