Engineering Reference
Capacitor Dielectric Reference
Engineering reference for capacitor dielectric materials including C0G, X7R, X5R, Y5V, Z5U, film, electrolytic, tantalum, and silver mica.
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- 9 min
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- Reference
- Last Updated
- July 16, 2026
Quick Lookup
C0G / NP0
Category: Class 1 ceramic
Best fit: RF networks, Oscillators, Filters.
Main caution: Limited capacitance range.
X7R
Category: Class 2 ceramic
Best fit: Power rail decoupling, Bypass capacitors, General filtering.
Main caution: DC bias derating.
X5R
Category: Class 2 ceramic
Best fit: Portable electronics, Digital decoupling, Low-voltage power rails.
Main caution: Limited upper temperature range.
Y5V
Category: Class 2 ceramic
Best fit: Noncritical bypassing, Low-cost consumer circuits, Loose filtering requirements.
Main caution: Poor tolerance.
Z5U
Category: Class 2 ceramic
Best fit: Noncritical decoupling, Consumer bypass capacitors, Loose-tolerance filtering.
Main caution: Poor stability.
Film
Category: Plastic film
Best fit: Audio circuits, Precision filters, Snubbers.
Main caution: Physically larger.
Electrolytic
Category: Aluminum electrolytic
Best fit: Bulk power filtering, Input capacitors, Output capacitors.
Main caution: Polarized.
Tantalum
Category: Tantalum electrolytic
Best fit: Power rail bulk decoupling, Portable electronics, Timing hold-up.
Main caution: Polarized.
Silver Mica
Category: Mica
Best fit: RF tuned circuits, Oscillators, High-Q filters.
Main caution: Limited capacitance range.
Dielectric Comparison Table
| Dielectric | Category | Temperature Stability | Tolerance | Voltage Characteristics | Aging | ESR | Frequency Characteristics |
|---|---|---|---|---|---|---|---|
| C0G / NP0 | Class 1 ceramic | Very high stability, about 0 ±30 ppm/°C | Typically ±0.1 pF to ±5% | Very low capacitance change with DC bias | Negligible aging | Very low ESR at high frequency | Excellent RF and high-frequency behavior |
| X7R | Class 2 ceramic | ±15% from -55°C to 125°C | Typically ±10% or ±20% | Capacitance can decrease significantly with DC bias | Ages logarithmically over time after last heat cycle | Low ESR, suitable for decoupling | Good general-purpose high-frequency decoupling behavior |
| X5R | Class 2 ceramic | ±15% from -55°C to 85°C | Typically ±10% or ±20% | Strong capacitance reduction with DC bias, especially in small packages | Ages logarithmically over time after last heat cycle | Low ESR | Good for compact decoupling across a broad frequency range |
| Y5V | Class 2 ceramic | +22% / -82% from -30°C to 85°C | Often -20% / +80% | Very large capacitance loss with DC bias | High aging compared with stable dielectrics | Low ESR, but capacitance stability is poor | Useful for noncritical bypassing where exact capacitance is not important |
| Z5U | Class 2 ceramic | +22% / -56% from 10°C to 85°C | Often wide tolerance such as -20% / +80% | Large capacitance change with DC bias | High aging compared with C0G and film capacitors | Low ESR for ceramic construction | Acceptable for loose bypassing but poor for precision timing or filtering |
| Film | Plastic film | Good to excellent depending on film material | Typically ±1% to ±10% | Very stable with voltage and usually non-polarized | Excellent long-term stability | Low ESR and low dissipation factor | Excellent for AC, pulse, snubber, and precision filter applications |
| Electrolytic | Aluminum electrolytic | Moderate; strongly affected by temperature and lifetime rating | Typically ±20% or wider | Polarized; must be used within rated voltage and polarity | Electrolyte dries over time; lifetime depends on temperature and ripple current | Moderate to high ESR, lower for low-ESR families | Best for bulk energy storage and low-frequency filtering |
| Tantalum | Tantalum electrolytic | Good compared with aluminum electrolytic capacitors | Typically ±10% or ±20% | Polarized; requires voltage derating for reliability | Good long-term stability when properly derated | Moderate ESR, low-ESR polymer variants available | Good bulk decoupling, especially where stable capacitance is needed |
| Silver Mica | Mica | Excellent stability over temperature | Typically ±0.5% to ±5% | Very stable with voltage | Excellent aging behavior | Very low loss | Excellent RF and high-Q performance |
Temperature Characteristics
| Dielectric | Temperature Stability | Typical Applications |
|---|---|---|
| C0G / NP0 | Very high stability, about 0 ±30 ppm/°C | RF networks, Oscillators, Filters, Timing circuits, Precision analog circuits |
| X7R | ±15% from -55°C to 125°C | Power rail decoupling, Bypass capacitors, General filtering, Bulk ceramic capacitance |
| X5R | ±15% from -55°C to 85°C | Portable electronics, Digital decoupling, Low-voltage power rails, Compact filters |
| Y5V | +22% / -82% from -30°C to 85°C | Noncritical bypassing, Low-cost consumer circuits, Loose filtering requirements |
| Z5U | +22% / -56% from 10°C to 85°C | Noncritical decoupling, Consumer bypass capacitors, Loose-tolerance filtering |
| Film | Good to excellent depending on film material | Audio circuits, Precision filters, Snubbers, AC coupling, DC link and pulse circuits |
| Electrolytic | Moderate; strongly affected by temperature and lifetime rating | Bulk power filtering, Input capacitors, Output capacitors, Energy storage, Audio coupling |
| Tantalum | Good compared with aluminum electrolytic capacitors | Power rail bulk decoupling, Portable electronics, Timing hold-up, Space-limited designs |
| Silver Mica | Excellent stability over temperature | RF tuned circuits, Oscillators, High-Q filters, Precision high-frequency networks |
ESR Comparison
| Dielectric | ESR / Losses | Frequency Characteristics |
|---|---|---|
| C0G / NP0 | Very low ESR at high frequency | Excellent RF and high-frequency behavior |
| X7R | Low ESR, suitable for decoupling | Good general-purpose high-frequency decoupling behavior |
| X5R | Low ESR | Good for compact decoupling across a broad frequency range |
| Y5V | Low ESR, but capacitance stability is poor | Useful for noncritical bypassing where exact capacitance is not important |
| Z5U | Low ESR for ceramic construction | Acceptable for loose bypassing but poor for precision timing or filtering |
| Film | Low ESR and low dissipation factor | Excellent for AC, pulse, snubber, and precision filter applications |
| Electrolytic | Moderate to high ESR, lower for low-ESR families | Best for bulk energy storage and low-frequency filtering |
| Tantalum | Moderate ESR, low-ESR polymer variants available | Good bulk decoupling, especially where stable capacitance is needed |
| Silver Mica | Very low loss | Excellent RF and high-Q performance |
Voltage Behaviour and Aging
| Dielectric | Voltage Behaviour | Aging |
|---|---|---|
| C0G / NP0 | Very low capacitance change with DC bias | Negligible aging |
| X7R | Capacitance can decrease significantly with DC bias | Ages logarithmically over time after last heat cycle |
| X5R | Strong capacitance reduction with DC bias, especially in small packages | Ages logarithmically over time after last heat cycle |
| Y5V | Very large capacitance loss with DC bias | High aging compared with stable dielectrics |
| Z5U | Large capacitance change with DC bias | High aging compared with C0G and film capacitors |
| Film | Very stable with voltage and usually non-polarized | Excellent long-term stability |
| Electrolytic | Polarized; must be used within rated voltage and polarity | Electrolyte dries over time; lifetime depends on temperature and ripple current |
| Tantalum | Polarized; requires voltage derating for reliability | Good long-term stability when properly derated |
| Silver Mica | Very stable with voltage | Excellent aging behavior |
Typical Applications
| Application | Typical Dielectrics | Lookup Note |
|---|---|---|
| Precision analog | C0G / NP0, Film, Silver Mica | Use stable, low-loss dielectrics with low aging. |
| Power supply decoupling | X7R, X5R | Check DC bias curves and effective capacitance at operating voltage. |
| Timing circuits | C0G / NP0, Film | Avoid high-K ceramics where drift and aging affect timing. |
| RF circuits | C0G / NP0, Silver Mica | Prefer high-Q, low-loss, stable capacitance. |
| Audio | Film, Electrolytic | Use film for stability; use polarized bulk parts only where bias is suitable. |
| Bulk storage | Electrolytic, Tantalum | Review ripple current, ESR, polarity, lifetime, and derating. |
| High temperature | C0G / NP0, X7R, Film | Verify exact family temperature rating and package limits. |
| Industrial | X7R, Film, Electrolytic | Use derating and lifetime review for voltage, temperature, and ripple. |
| Automotive | X7R, C0G / NP0, Film | Check AEC-qualified parts and full temperature, vibration, and voltage stress. |
Advantages and Disadvantages
| Dielectric | Advantages | Disadvantages |
|---|---|---|
| C0G / NP0 | Stable capacitance, Low loss, Low dielectric absorption, Good RF performance | Limited capacitance range, Higher cost per uF, Larger size for high values |
| X7R | High capacitance density, Wide availability, Good temperature range, Low ESR | DC bias derating, Aging, Microphonic behavior in some applications |
| X5R | High capacitance density, Small package availability, Low ESR, Cost effective | Limited upper temperature range, DC bias derating, Aging |
| Y5V | Very high capacitance density, Low cost, Small package options | Poor tolerance, Poor temperature stability, Severe DC bias loss, High aging |
| Z5U | High capacitance density, Low cost, Compact size | Poor stability, Limited temperature range, DC bias derating, Not suitable for precision circuits |
| Film | Stable, Non-polarized, Low loss, Good pulse handling, Long life | Physically larger, Lower capacitance density, Higher cost for large values |
| Electrolytic | High capacitance, High voltage availability, Low cost per uF, Useful bulk storage | Polarized, Limited lifetime, Higher ESR, Large size, Leakage current |
| Tantalum | High capacitance density, Stable capacitance, Low leakage options, Compact packages | Polarized, Surge sensitivity, Derating required, Failure mode concerns |
| Silver Mica | High Q, Excellent stability, Low loss, Good RF behavior | Limited capacitance range, Higher cost, Larger than comparable ceramics |
Engineering Notes
- Precision analog: prefer C0G/NP0, film, or silver mica.
- Power decoupling: verify MLCC DC bias and effective capacitance.
- Timing circuits: avoid Y5V and Z5U for stable time constants.
- RF circuits: check loss, Q, package parasitics, and self-resonance.
- Bulk storage: review ESR, ripple current, polarity, and lifetime.
- Industrial and automotive: verify temperature, qualification, and derating.
Reference Scope
This page is a lookup reference. For explanatory selection guidance, use the capacitor dielectric guide. For production release, verify part-specific datasheets, DC bias curves, reliability ratings, and manufacturer qualification data.
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FAQ
What is a capacitor dielectric?
A capacitor dielectric is the insulating material between conductive plates. It determines stability, capacitance density, voltage behavior, losses, aging, leakage, and frequency characteristics.
Which dielectric is most stable?
C0G/NP0, silver mica, and many film capacitors are stable choices. C0G/NP0 is common for small precision and RF values.
What is C0G or NP0 used for?
C0G/NP0 is used for RF networks, oscillators, precision filters, timing circuits, and analog paths that need stable low-loss capacitance.
What is X7R used for?
X7R is widely used for ceramic decoupling, bypassing, general filtering, and compact bulk capacitance where moderate stability is acceptable.
What is the difference between X5R and X7R?
X5R has a lower upper temperature rating than X7R. Both can lose capacitance with DC bias, especially in small MLCC packages.
Are Y5V and Z5U precision dielectrics?
No. Y5V and Z5U are low-stability high-K ceramic dielectrics and are unsuitable for precision timing, precision filters, and stable analog networks.
When should film capacitors be used?
Film capacitors are useful for AC coupling, audio, precision filters, snubbers, pulse circuits, and applications needing low loss and stable voltage behavior.
Why do electrolytic capacitors age?
Aluminum electrolytic capacitors contain electrolyte that changes or dries over time. Temperature and ripple current strongly affect lifetime.
Do tantalum capacitors need voltage derating?
Yes. Tantalum capacitors should be derated and protected from surge stress, reverse polarity, and excessive ripple current.
Does dielectric type affect ESR?
Yes. ESR depends on dielectric, construction, package, frequency, temperature, and part series. Ceramic, film, electrolytic, tantalum, and mica families have different ESR behavior.
Further Reading
- Engineering Reference hub
- Capacitors Reference category
- Capacitor Calculator category
- Manufacturer datasheets for DC bias, ESR, ripple current, and qualification data.