The table below provides a brief summary of different capacitor types and their relative merits, arranged approximately in terms of decreasing quantity (or increasing quality) of capacitance offered by each type.
| Capacitor type | Sub-type/variant | Approx. value range | C*V product range | Advantages | Disadvantages/things to beware of | Good for | Lousy for | |
|---|---|---|---|---|---|---|---|---|
| C | V | |||||||
| Electric double layer, Supercaps | 6.8mF to 4000F | 2.1 to 75v | .03 to 10,000 | Exceptionally high C/V ratio. Possible alternative to secondary (rechargeable) batteries, variations suitable for low power (memory, RTC backup supplies) and high power (battery replacement/automotive/traction) applications available. | Polarized, low per-cell voltage; power management circuitry usually req.d for use as energy storage device. Leakage current often quite high. Service life strongly temperature dependent, possible toxicity issues depening on electrolyte formulation. | Storage for energy harvesting applications, battery supplement/replacement | Signal applications, high-temperature applications | |
| Aluminum | Standard Electrolytic | 0.1u to 2.2F | 4 to 550V | 5E-6 to 22 | Inexpensive, high C/V ratio, large values available. Capable of self-healing. | Polarized, service life & device parameters strongly temperature dependent. High ESR, poor linearity, dielectric degrades if stored discharged for extended periods. Potentially toxic depending on electrolyte formulation. | Bulk filtering at frequencies into the 10’s of kHz | Precision filtering, RF, signal applications |
| Bipolar | .22u to 6.8mF | 6.3 to 50V | 1E-5 to 0.05 | Similar to standard aluminum electrolytic, but capable of withstanding polarity reversal | Similar to standard electrolytic, though non-polarized. Not recommended for continuous AC use due to high ESR & resulting power dissipation | DC applications with uncertain or occasionally-reversed polarity | Precision filtering, RF, signal applications, continuous AC applications | |
| Polymer | 22n to 4.7mF | 2 to 100V | 2E-6 to 0.016 | Improved ESR & device longevity vs. standard electrolytic types due to use of solid electrolyte instead of liquid. | Higher cost, limited range of available device values, limited self-healing capability. | Bulk filtering at frequencies into the low 100’s of kHz. | Precision filtering, RF, signal applications | |
| Tantalum | Ta/MnO2 | 100nF to 2.2mF | 2.5 to 125V | 2E-6 to 0.12 | Good C/V ratio & loss characteristics among electrolytic types, good service life potential due to absence of evaporable/leakable liquids. Wide temperature range, self-healing when properly applied | Device construction/chemistry is similar to many pyrotechnic devices and may behave as such upon failure; careful design is mandatory. As a rule of thumb, de-rate voltage by 50% minimum and ensure that application will not apply surge current in excess of the test value. | Bulk filtering up to low 100’s of kHz in space-constrained, extreme temperature, or long-life applications. | precision filtering, RF,signal applications, any application developed without due caution and attention. |
| Wet | 1.7uF to 24mF | 10 to 125V | 2E-4 to 1.2 | Good C/V ratio, low ESR, good reliability & stability among liquid-electrolytic types. Good self-healing characteristics, little to no risk of pyrotechnic failure, reduced voltage de-rating and higher capacitance/voltage values available relative to solid tantalum devices. | Costly, mechanically vulnerable to vibration when improperly secured. Enclosed electrolyte is generally quite corrosive. | Bulk filtering to 10’s of kHz, legacy high-reliability applications. | Cost-critical applications, signal & RF applications | |
| Polymer | 4.7nF to 1.5mF | 2.5 to 75V | 3E-5 to 1E-2 | Good C/V ratio, Low ESR among electrolytic types, little to no risk of pyrotechnic failure. Improved high-frequency performance over other tantalum types. | Poorer temperature tolerance, less effective self-healing, higher leakage than other tantalum types. | Bulk filtering up to low 100’s of kHz, particularly in high-density, temperature-limited applications. | Precision filtering, RF,Signal applications | |
| Niobium Oxide | 2.2uF to 1mF | 1.8 to 10V | 2E-5 to 4E-3 | Good C/V ratio, low ESR among electrolytic types, tantalum alternative with reduced risk of pyrotechnic failure & less de-rating required. Potential supply chain advantages over tantalum due to differences in material availability. | Limited voltage ranges available | Bulk filtering at frequencies from upper 10’s of kHz to lower 100’s of kHz, particularly in high-density applications. Alterntive to tantalum for many applications. | Precision filtering, RF, signal applications | |
| Film | Polyester/Polyethylene Terephthalate (PET) | 270pF to 220uF | 50V to 1kV | 3E-8 to 0.07 | Lowest cost, highest C/volume of common film types. Modest temperature capability, though most devices not reflow-compatible. Good self-healing characteristics with certain construction types | Relatively high losses and parametric variance with temperature and frequency compared to other common film types. | AC line filtering applications, signal applications < 100kHz where cost is a dominant consideration. | RF applications, low-voltage power filtering. |
| Polyethylene Napthalate | 1nF to 1uF | 16 to 630V | 1E-7 to 3E-4 | Similar to polyester/PET, but with improved temperature capability that enables reflow solder process compatibility | Higher cost, somewhat poorer dielectric performance than polyester/PET | Applications calling for polyester-like performance but with higher temp. & reflow process capabilities | Low-voltage power filtering | |
| Polypropylene | 100pF to 3mF | 50V to 3 kV | 6E-9 to 2 | Good parameter stability over time, temp, & frequency relative to to other film types, low losses & susceptiptibility to moisture absorption. Relatively low cost, fair self-healing characteristics with certain construction types. | Poorest temperature capability among common film types. | Precision filtering where relatively high C values are called for, high-power mid-frequency (10^3~10^6 Hz) applications such as induction heating & inverter drives. | High-temperature applications, RF applications & low-voltage power filtering | |
| Polyphenylene Sufide | 100pF to 0.39uF | 10 to 250V | 2E-9 to 4E-5 | Similar to polypropylene, but with improved temperature capability that enables reflow solder process compatibility | Higher cost, somewhat poorer dielectric performance than polypropylene. | Applications calling for polypropylene-like performance but with higher temp. & reflow process capabilities | Low-voltage power filtering | |
| Other types | 470pF to 22uF | 16V to 1.5kV | Variable performance depending on dielectric, less common than other film capacitor types. Includes paper, polystyrene, polycarbonate, etc. | |||||
| Ceramic | Class 1 dielectrics (ex: C0G) | 0.1pF to 0.1uF | 16V to 3 kV | 3E-12 to 4E-5 | Stable device parameters over temperature, voltage, frequency. Good linearity, commonly used for timing & signal applications. Devices with controlled temperature coefficients available for temperature compensation applications. Little to no piezoelectric/microphonic behavior, low cost compared to other temp.-stable device types. | Available only in relatively small values, prone to mechanically-induced failure due to brittleness of materials used. | Precision filtering, timing, signal applications, some RF applications | Bulk filtering, decoupling of frequencies below a few 100s of kHz |
| Class 2 dielectrics (Ex: X5R, X7R, etc.) | 10pF to 100uF | 4V to 5 kV | 4E-10 to 2E-3 | Low ESR, good C/V ratio among ceramic types, commonly used for decoupling supply rails & low-precision filtering. | Significant parameter shifts with time, voltage, temperature, prone to mechanically induced failure, piezoelectric/microphonic | IC supply rail decoupling, power filtering at high 10’s of kHz to several MHz, low-precision signal filtering | Low frequency bulk filtering, precision filtering/timing/signal applications | |
| Class 3 dielectrics (Ex: Z5U, Y5V) | 100pF to 470uF | 6.3V to 50 kV | 1E-8 to 1E-2 | Highest C/V ratios of all ceramic types, often used in AC line filtering applications. | Extreme parameter dependence on time, voltage, temperature negates advantages of high C/V ratio in many applications. Prone to mechanical failure due to material brittleness. Highly piezoelectric/microphonic. | EMI filtering on AC lines, other applications calling for low-cost capacitors and having a wide tolerance for parametric variation. | Any application reqiring parameter stability or linearity. | |
| Mica/PTFE | 1pF to 15nF | 50V to 30kV | 1E-10 to 5E-5 | Excellent parameter stability, very low loss, wide temperature range | High cost, only low C values available | RF applications (filtering, tuning, broadcast TX) timing circuits, precision test & measurement | Bulk filtering | |
| Silicon | 0.2pF to 3.3uF | 10 to 100V | 1E-11 to 4E-5 | Good electrical properties, very small packages available, often suitable for embedding in PCB. | High part and assembly costs. | Filtering, decoupling up to RF frequencies in extremely space-constrained applications. | cost-sensitive applications | |
| Thin film | 50fF to 0.1uF | 10 to 50v | 8E-13 to 5E-6 | Excellent electrical properties, very tight parameter tolerances available, commonly sold in industry-standard surface mount packaging. | Only small values available, attention to layout particularly important with smaller values. | RF & microwave tuning, filtering applications | Bulk filtering | |
| Trimmers, variable caps | 1pF to .18nF | 25 to 500V | 3E-11 to 2E-8 | Allow mechanical adjustment of a capacitance value. | Wide variation in construction & dielectric types yields significant variance in performance. Limited to relatively small capacitance values. Correlation of mechanical input to capacitance value varies with design, some types more susceptible to drift due to environmental factors than others. | tuning, matching, & calibration circuits | bulk filtering, decoupling |
