MEMS and sensors

When choosing the measurement range of a MEMS accelerometer (for example, ±2 g versus ±16 g), which reasoning is correct?

  1. AA wider range can measure larger shocks, but with the same number of bits the resolution becomes coarser
  2. BA wider range always gives finer resolution
  3. CThe range determines only the sensor's power consumption
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Answer: A. A wider range can measure larger shocks, but with the same number of bits the resolution becomes coarser

With the same output bit count, a wider range means more acceleration per LSB, making small changes harder to distinguish. A narrow range with high resolution suits step counting and tilt detection, while a wide range suits collision and drop detection, so the range is chosen for the application. Many sensors allow the range to be switched.

  • A. Correct. Range and resolution trade off.
  • B. A wider range makes resolution coarser at the same bit count.
  • C. The range relates to resolution and the maximum measurable acceleration.
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More MEMS and sensors questions

  1. In a parallel-plate electrostatic actuator, what is the phenomenon called in which, as the voltage rises, the movable electrode suddenly snaps to the fixed electrode once it passes a certain position?
  2. Which method is widely used to evaluate the bias stability (slow drift of the output) of MEMS gyroscopes?
  3. What is the damping called that arises when a MEMS movable plate moves toward a nearby fixed surface and squeezes out the gas between them?
  4. In very small MEMS accelerometers and gyroscopes, which noise, caused by the proof mass jiggling randomly through thermal interaction with surrounding gas molecules and the like, is one limit on resolution?
  5. Which statement correctly describes detecting very small masses by using the change in resonant frequency when material adheres to a tiny cantilever or a quartz crystal resonator?