FAQ for F²MC-16LX Family

Noise

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1. What countermeasure is taken against unnecessary radiation noise in a microcomputer?
2. Which has a wider tolerance on unnecessary radiation noise, a Flash microcomputer or Mask microcomputer?
3. Which has a wider tolerance for noise, a Flash microcomputer or Mask microcomputer?
4. Why noise can be reduced when the following noise countermeasures are taken? 1) Embedding a capacitor in the I/O and power supply interconnects. 2) Optimizing an oscillation circuit.

What countermeasure is taken against unnecessary radiation noise in a microcomputer?

• Answer :
  Countermeasure against unnecessary radiation noise depends on a product type. The standard countermeasures include oscillation circuit optimization, layout of power supply and GND, built-in of an internal capacitor, and so on. Moreover, countermeasures are further taken depending on various products such as a clock modulation, and power filter.

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Which has a wider tolerance on unnecessary radiation noise, a Flash microcomputer or Mask microcomputer?

• Answer :
  The differences in tolerance for unnecessary radiation noise between a Flash microcomputer and Mask microcomputer depend on a product and a band in question. We recommend to evaluate unnecessary radiation noise for both microcomputers.

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Which has a wider tolerance for noise, a Flash microcomputer or Mask microcomputer?

• Answer :
  The superiority or inferiority of the tolerance for noise in a Flash microcomputer and Mask microcomputer depends on a product. We recommend to evaluate the tolerance for noise for both products.

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Why noise can be reduced when the following noise countermeasures are taken? 1) Embedding a capacitor in the I/O and power supply interconnects 2) Optimizing an oscillation circuit.

• Answer :
  
  
  1. Embedding a capacitor in the I/O and power supply interconnects can prevent external propagation of noise elements.
  2. Optimizing the drive performance of oscillation reduces higher harmonic waves.