Class 1 ceramic capacitors (usually C0G or NP0) are the choice when capacitance must remain predictable. Class 2 ceramics (such as X7R and X5R) provide much more capacitance in a small package, but their effective value changes with temperature, applied DC voltage, and time.
The right choice is therefore not the part with the largest printed capacitance. Choose the dielectric that delivers the required effective capacitance under your circuit’s actual voltage, temperature, frequency, tolerance, package, and lifetime conditions.
As an Amazon Associate I earn from qualifying purchases.
What Class 1 and Class 2 mean
The terms Class 1 and Class 2 describe two broad ceramic-dielectric performance categories. TDK also calls them Class I and Class II. Class 1 is the temperature-compensating category; C0G and NP0 are its familiar designations. Class 2 uses high-dielectric-constant materials; X7R and X5R are common examples. Murata’s comparison explains the distinction in terms of stability, dielectric constant, bias behavior, and aging: Murata ceramic-capacitor comparison FAQ.
In practical terms, Class 1 trades capacitance density for predictability. Class 2 trades some predictability for substantially higher capacitance in a given volume. Neither class is universally better, and the same circuit can legitimately use both.
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
Class 1 vs. Class 2 at a glance
| Design axis | Class 1: C0G/NP0 examples | Class 2: X7R/X5R examples |
|---|---|---|
| Temperature stability | Small capacitance change over temperature; TDK describes C0G/NP0 as highly stable. | Larger temperature-related change than Class 1; the permitted behavior depends on the specific code and part. |
| DC-bias dependence | Murata reports no DC-bias characteristic for its temperature-compensating category. | Applied DC voltage changes effective capacitance. The amount is part-dependent and must be read from the manufacturer’s curve. |
| Aging | Murata reports no aging characteristic for its Class 1 category. | Murata reports an aging characteristic for its high-dielectric category. |
| Capacitance density | Lower relative dielectric constant limits available capacitance and usually requires more board area or volume. | Higher relative dielectric constant enables larger capacitance in a smaller package. |
| Typical uses | Oscillation, tuning and filtering, precision coupling, and impedance matching. | Bypass, smoothing, power-rail decoupling, and general coupling. |
| Primary design priority | Stable, low-loss, repeatable capacitance. | High capacitance where space and cost are constrained. |
The categories and examples are summarized by TDK’s Class I/Class II FAQ and Murata’s comparison. The table is a selection guide, not a substitute for the exact component datasheet.
Why the dielectric creates the tradeoff
Lower dielectric constant, higher stability
A capacitor’s capacitance depends partly on the dielectric constant of the ceramic between its electrodes. Class 1 materials have a lower relative dielectric constant. That limits how much capacitance can be packed into a particular case size, but the material’s electrical behavior changes little as operating conditions move.
High dielectric constant, higher density
Class 2 materials have a much higher relative dielectric constant. Manufacturers can therefore build a physically small component with a large nominal capacitance. The cost is stronger dependence on temperature, electric field, and elapsed time. A Class 2 part that is marked with the same nominal value as a Class 1 part may deliver a different value once it is installed in a biased, warm circuit.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Fix the driver behind crashes, sound loss and screen glitches3Clear out junk files and repair common Windows errorsTemperature behavior and the meaning of C0G, NP0, X7R, and X5R
C0G and NP0 identify Class 1 behavior intended to keep capacitance nearly constant across the component’s specified temperature range. They are consequently useful in frequency-determining networks, filters, resonators, and precision timing or matching paths where a changing capacitance shifts circuit behavior.
X7R and X5R identify Class 2 temperature characteristics. They allow more capacitance than C0G/NP0, but the capacitance moves more with temperature. The exact allowed range belongs to the individual code and part number; the label alone does not provide every electrical limit a design needs.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
Analog Devices discusses the combined effects of temperature and voltage in its technical article, Temperature and Voltage Variation of Ceramic Capacitors. When temperature is critical, use the capacitance-versus-temperature graph for the selected part rather than assuming every capacitor carrying the same three-character code behaves identically.
DC bias: why a nominal X7R value can be misleading
Class 2 multilayer ceramic capacitors are polarized by the electric field created when a DC voltage is applied. Their effective AC capacitance can fall as the bias voltage increases. The drop depends on capacitance value, rated voltage, case size, electrode construction, temperature, and the particular manufacturer’s process.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
An X7R or X5R marking specifies a temperature category; it does not specify how much capacitance will be lost at your operating voltage. Two parts with the same nominal capacitance, voltage rating, and temperature code can have materially different bias curves. Analog Devices specifically recommends checking the individual component’s bias-versus-capacitance data: its voltage-variation guidance.
Calculate with effective capacitance
For a Class 2 part, start with the capacitance required by the circuit and then evaluate the selected part at its worst-case DC bias and temperature. If the circuit needs a minimum value, design against the lowest value shown by the manufacturer’s curves, including tolerance and aging where those data are provided. Do not apply one universal derating percentage: the available evidence does not support a single factor for every package and part construction.
Why voltage rating alone is insufficient
A higher voltage rating can reduce bias-related loss in some families, but the relationship is not universal enough to choose by voltage rating alone. Compare the actual curves for the candidate part at the voltage that will be present across the capacitor, including start-up, ripple, transient, and abnormal operating conditions.
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Aging and long-term drift
Murata identifies an aging characteristic for its high-dielectric Class 2 category and no aging characteristic for its Class 1 temperature-compensating category. Aging is a gradual change in capacitance with time after a thermal or manufacturing-related reset condition. In a frequency-sensitive circuit, that drift can change the operating point; in a bulk decoupling position, the same drift may be acceptable if sufficient capacitance margin exists.
KEMET likewise describes C0G and U2J technologies as having negligible capacitance change with DC bias and nearly no change over time in its ceramic-technologies article. Treat that as technology guidance, not as a guarantee for every manufacturer’s part. The selected datasheet remains authoritative.
Capacitance density, size, and mechanical constraints
When board area or height is limited, Class 2 is usually the practical route to a large capacitance. The high dielectric constant lets a small multilayer component provide the values commonly needed for supply bypassing, smoothing, and decoupling. Class 1 parts reach lower values in the same case size, so obtaining more capacitance may require a larger package, several parallel parts, or a different capacitor technology.
That density advantage has electrical consequences. In many Class 2 families, increasing nominal capacitance within a fixed case size reduces the voltage at which the part retains its rated value. A physically larger or higher-voltage part may preserve more effective capacitance, but the tradeoff must be verified with the manufacturer’s data rather than inferred from the marking.
Where each class is normally used
Class 1 applications
- Oscillation and timing: Stable capacitance helps keep an oscillator’s frequency from moving with temperature or bias.
- Tuning and filtering: Filter poles and resonant frequencies remain more predictable when the capacitor value is stable.
- Impedance matching: RF and high-speed matching networks benefit from low loss and repeatable capacitance.
- Precision coupling: Use Class 1 when the coupling network’s response must remain consistent over environmental changes.
These examples follow Murata’s listed Class 1 uses in its category comparison.
Free tools Windows power users keep installed
One-click scans. No signup required.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
Class 2 applications
- Bypass and decoupling: A high nominal value in a small package can supply transient current locally and reduce rail impedance.
- Smoothing: Class 2 density is useful for reducing ripple when the remaining effective capacitance is sufficient.
- General coupling: Audio, sensor, and signal paths can use Class 2 when drift and voltage dependence do not compromise the required response.
Murata lists bypass, smoothing, decoupling, and coupling as Class 2 examples. Coupling appears in both categories, so the application label alone does not determine the dielectric; the required stability does.
Step-by-step selection procedure
- Define the electrical job. Decide whether the capacitor sets a frequency or filter corner, matches an impedance, blocks DC, stores charge, or suppresses supply noise. Write down the minimum and maximum acceptable capacitance at the circuit node.
- Choose the stability level. Start with Class 1 when the value directly controls frequency, tuning, filtering, or matching. Start with Class 2 when the circuit needs substantially more capacitance than a practical Class 1 part can provide.
- Specify operating conditions. Record DC voltage, AC ripple, frequency, ambient and component temperature, transients, and the expected lifetime. Include the highest credible voltage, not only the nominal rail.
- Shortlist exact part numbers. Compare C0G/NP0, X7R, or X5R parts by capacitance, rated voltage, tolerance, package, temperature range, and construction. A dielectric code without a part number is not enough for final selection.
- Read the bias curve. For each Class 2 candidate, find capacitance-versus-DC-bias data and read the value at the actual operating voltage and temperature. If the manufacturer supplies curves for multiple frequencies, use the one closest to the circuit.
- Apply tolerance and aging. Combine the initial tolerance with the worst-case temperature, bias, and aging shifts supplied for that part. Check whether the resulting minimum and maximum values still satisfy the circuit.
- Check mechanical and layout limits. Confirm case dimensions, pad pattern, board clearance, mounting stress limits, and availability. Package choice can influence electrical behavior, especially for high-value Class 2 parts.
- Validate the assembled design. Measure the circuit at temperature and voltage extremes, or use a production-qualified model that includes the selected part’s effective capacitance. Recheck after thermal cycling if long-term stability matters.
How to read a capacitor datasheet
Capacitance and tolerance
The printed capacitance is normally a nominal room-condition value. Tolerance tells you the allowed initial spread around that value, not the value after DC bias, temperature change, or aging. For a precision circuit, use the full tolerance range in calculations.
Rated voltage and operating voltage
Rated voltage is a maximum electrical rating under the manufacturer’s stated conditions. It is not a promise that the capacitor will retain its nominal capacitance at that voltage. Compare the effective-capacitance curve at your working voltage and leave appropriate margin for transients.
Temperature range and characteristic
The temperature code describes the permitted temperature-related behavior for that category. It does not replace the part’s detailed capacitance-versus-temperature graph, nor does it describe DC-bias loss. Use both the code and the graph.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Repair Windows errors before they cause bigger problemsFix Now →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Package and frequency information
Case size, electrode design, and measurement frequency can change the reported capacitance. Use data measured under conditions that resemble the circuit, and verify that the selected package is compatible with the assembly process.
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Common selection mistakes and fixes
| Mistake | What goes wrong | Better approach |
|---|---|---|
| Choosing by nominal capacitance only | A Class 2 part may deliver far less capacitance under DC bias than its marking suggests. | Read the exact part’s bias and temperature curves and design for effective capacitance. |
| Assuming every X7R or X5R behaves the same | The temperature code does not reveal the part’s voltage coefficient. | Compare manufacturer data for capacitance, package, voltage rating, and construction. |
| Using a single generic derating factor | Bias loss varies too widely among parts for one percentage to be reliable. | Use the selected part’s measured or specified curves at the actual operating point. |
| Using Class 2 in a frequency-setting network without checking drift | Temperature, bias, and aging can move the frequency or filter corner. | Use C0G/NP0 where stability is required, or prove that the Class 2 drift remains within the system budget. |
| Assuming Class 1 is always the answer | The required capacitance may be unavailable or physically impractical in Class 1. | Use Class 2 with adequate effective-capacitance margin when density matters more than precision. |
| Ignoring coupling’s dual use | Classifying an application as Class 1 or Class 2 by name can lead to the wrong dielectric. | Decide from the coupling network’s stability, loss, voltage, and capacitance requirements. |
When can one class replace the other?
Replacing Class 1 with Class 2
This is reasonable only when the circuit tolerates capacitance movement over voltage, temperature, and time. Recalculate the circuit using the lowest effective capacitance and verify the resulting frequency, gain, phase, or transient response. If the capacitor participates in resonance or precision matching, replacement usually requires a complete stability check rather than a value-for-value substitution.
Replacing Class 2 with Class 1
A C0G/NP0 substitute can improve stability, but it may provide insufficient capacitance, require a larger case, or increase component count. Confirm that the available Class 1 value meets the circuit’s minimum requirement and fits the mechanical design.
A practical decision framework
- Choose Class 1 first when capacitance accuracy, low loss, temperature stability, or long-term repeatability is the primary requirement.
- Choose Class 2 first when the circuit needs high capacitance in limited volume and can tolerate a specified change in effective value.
- Use both when a design needs a stable small-value capacitor for signal integrity and a high-density Class 2 capacitor for energy storage or rail decoupling.
- Escalate to detailed validation when the part is near its voltage rating, the temperature range is wide, the capacitance is large for the package, or the capacitor sets a critical circuit parameter.
Key takeaways for a reliable design
Class 1 C0G/NP0 ceramics provide the most predictable capacitance and are suited to oscillation, tuning, filtering, matching, and other precision functions. Class 2 X7R/X5R ceramics provide much greater capacitance density and are widely suited to bypassing, smoothing, decoupling, and non-critical coupling.
The decisive specification is the value the circuit receives in operation, not the number printed on the reel or body. For every Class 2 candidate, inspect the exact part’s DC-bias and temperature behavior, then include tolerance, aging, rated voltage, package, frequency, and environmental limits in the design review. Manufacturer references from Murata, TDK, Analog Devices, and KEMET all emphasize consulting the individual component data for the final decision.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
