MMA7341L 3-Axis Accelerometer ±3/11g

24 July 2014 - Accelerometers, Hypsine Tutorial Point, Sensors - Hypsine Electronics - No Comments

Price : Rs. 1,325/- (Tax excl.)
Part No: SEN-1549
Weight: 0.05Kg
Made by: Pololu – USA

MMA7341L 3-Axis Accelerometer ±3/11g

Description: This tiny triple-axis accelerometer is a basic carrier board for the Freescale MMA7341L XYZ-axis accelerometer, a great low-g sensor with analog voltage outputs and adjustable sensitivity (±3 g or ±11 g), and a 0g-detect digital output that signals when the board is in free-fall. The board operates from 2.2 to 3.6 V.

The MMA7341 is a great IC, but its small, leadless packages makes it difficult for the typical student or hobbyist to use. This carrier board includes all of the components in the part’s recommended connection diagram and breaks the pins out to a 0.5″×0.4″ (12.7×10.2 mm) 10-pin DIP form factor that is easy to use with standard solderless breadboards and 0.1″ perfboards.

The MMA7341L carrier offers selectable ±3g or ±11g sensitivities. It has a 0g-detect output that goes high when the board is in free fall.

Note:

  • A 10×1 strip of 0.1″ header pins is included. These pins are not pre-installed.

Specifications

  • Dimensions: 0.4″ x 0.5″ x 0.09″ (without header pins)
  • Operating voltage (VDD): 2.2-3.6 V (pins are not 5V-tolerant)
  • Supply current: 0.5 mA
  • Sleep-mode current draw: < 3 µA
  • Output format: 3 analog voltages (one signal for each axis) centered at VDD/2
  • Sensitivity range (selectable using g-Select pin):  ±3g (default) or ±11g
  • Weight without header pins: 0.012 oz (0.35 g)

Using the Sensor

The board is powered by supplying 2.2 to 3.6 V on the VDD pin. Note that this part does not have 5V-tolerant pins, so external components (such as voltage dividers) are required when interfacing the board’s g-Select, Self Test, and Sleep pins with 5V systems. Connections to these pins are optional; the board will work with these pins disconnected as long as the sleep pin is driven high with an on-board solder bridge as described below.

The sleep pin, Sleep, is internally pulled low, which puts the board into low-power sleep mode by default. You must drive this pin high to use the board. This can be accomplished with a microcontroller I/O line. If you want selective control of sleep mode, or you can make a solder bridge across the SMT jumper pads labeled “ON” on the silkscreen side of the board to connect the sleep pin to VDD and enable the board by default.

The accelerometer X, Y, and Z outputs are three separate analog voltages centered at VDD/2. Positive accelerations along an axis increase that axis’s output voltage above VDD/2 and negative accelerations decrease the output voltage below VDD/2. The outputs will always be within the range of 0 to VDD.

The sensitivity selection pin, g-Select, is internally pulled low, which selects for a default sensitivity of ±3g (440 mV/g) on the MMA7341L carrier. Driving the pin high selects for a sensitivity of ±11g (118 mV/g) on the MMA7341L carrier. The 0g-Detect pin outputs high when all three axes simultaneously detect 0g, which happens when the board is in free-fall. The Self Test pin is pulled low on the board and can be left disconnected.

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