Q&A Corner : Answer

What kind of capacitors are there?

The following table shows the kind of capacitors intended for general consumer electronics.

Kind Feature Fit for
Aluminum Electrolytic Capacitor

Aluminum electrolytic capacitors have large capacitance, and their ESR/ESL frequency characteristics are not good. Therefore, they are not suitable for power lines near IC and decoupling. As they have polarity, reverse voltage and overvoltage cause leakage of liquids and/or explosion. You should mind for that in using them.

voltage smoothing in power lines, power backup
Tantalum Electrolytic Capacitor

Features of tantalum electrolytic capacitors are like aluminum electrolytic capacitors. Different points are that they are smaller than and superior in ESR/ESL frequency characteristics to aluminum capacitors. However, their ESR/ESL characteristics do not reach ceramic capacitors. As they also have polarity, reverse voltage and overvoltage cause fuming and/or heating.

voltage smoothing in power lines, bypass
Film Capacitor

Film Capacitors have low capacitance. Their capacitance does not change by environmental factors such as temperature, voltage and so on. They always keep constant characteristics.

analog circuit
Multilayer Ceramic Capacitor

Capacitance range of multilayer ceramic capacitors spreads roughly from 0.5pF to 100uF. They have good ESR/ESL frequency characteristics enough to pass analog signals without any distortion by selecting correct capacitance. Capacitors classified to high dielectric type have large capacitance and their capacitance depend largely on voltage and temperature. It is important to take this into account when dealing with the circuit that requires the correct capacitance. As multilayer ceramic capacitors are inexpensive and small, large quantities can be mounted even in a small equipment.

analog, digital, power circuit