Polymer electrolytic
A polymer capacitor, or more accurately a polymer electrolytic capacitor, is an electrolytic capacitor (e-cap) with a solid electrolyte of a conductive polymer. There are three different types:
A fourth type, Polymer niobium electrolytic capacitors are no longer in production.
Polymer Ta-e-caps are available in rectangular surface-mounted device (SMD) chip style. Polymer Al-e-caps and hybrid polymer Al-e-caps are available in rectangular surface-mounted device (SMD) chip style, in cylindrical SMDs (V-chips) style or as radial leaded versions (single-ended).
Polymer electrolytic capacitors are characterized by particularly low internal equivalent series resistances (ESR) and high ripple current ratings. Their electrical parameters have similar temperature dependence, reliability and service life compared to solid tantalum capacitors, but have a much better temperature dependence and a considerably longer service life than aluminum electrolytic capacitors with non-solid electrolytes. In general polymer e-caps have a higher leakage current rating than the other solid or non-solid electrolytic capacitors.
Polymer electrolytic capacitors are also available in a hybrid construction. The hybrid polymer aluminum electrolytic capacitors combine a solid polymer electrolyte with a liquid electrolyte. These types are characterized by low ESR values but have low leakage currents and are insensitive to transient, however they have a temperature-dependent service life similar to non-solid e-caps.
Polymer electrolytic capacitors are mainly used in power supplies of integrated electronic circuits as buffer, bypass and decoupling capacitors, especially in devices with flat or compact design. Thus they compete with MLCC capacitors, but offer higher capacitance values than MLCC, and they display no microphonic effect (such as class 2 and 3 ceramic capacitors).
Aluminum electrolytic capacitors (Al-e-caps) with liquid electrolytes were invented in 1896 by Charles Pollak, see electrolytic capacitor.
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