microcontroller design tips in emc

Introduction To Microcontroller Design Tips

As the electronic components continue to shrink in size with the advancement of semiconductor
and packaging technology, the ability of these smaller MCU to withstand the effect of electromagnetic interference is less compared to its bigger size counterparts. Hence the importance of designing electronic devices that can withstand a certain level of immunity in noisy environment has to be considered at the start of a design.

The cycle of a product development using microcontroller design starts at specifications definition, to circuit design, components selection, printed circuit board design, making prototype, reliability and EMC testing, market testing and finally product launch. The cost of EMC consideration and solutions are lowest at design stage and will escalate exponentially when products have been launched to the market. If a device failed due to electromagnetic interference in the market, it will have to be solved on site by using more expensive solutions for instance standalone filters, shieldings etc or even recall from the market if it is a major defect. Hence it is of extreme importance that the EMC design is taken into consideration at the design stage. The followings are some tips that one may consider when designing any electronics device.

Microcontroller Design Component Selection

As far as possible, the components used should be leadless type instead of leaded type as the leaded type have more parasitic and capacitive effect at high frequencies. Surface mount resistors, capacitors, inductors, and other SMT components are preferred. MCU selection is done based on the assurance and specifications from the manufacturer that the EMC aspects are taken into consideration in the design of the device. For instance, build in clamping diodes at the inputs of the ports to reduce the effect of electrostatic discharge on the ports.