The standard capacitance chart uses a 3-digit EIA code where the first two digits are significant figures and the third is the multiplier in picofarads (e.g., 104 = 10 × 10^4 pF = 100 nF). However, for Multi-Layer Ceramic Capacitors (MLCCs), the nominal chart value is only valid at 0V DC. To design reliable power and signal circuits, you must apply DC bias and temperature derating to find the real-world effective capacitance.
The Standard Capacitance Value Chart (EIA E-Series)
How to read this table: The '3-Digit Code' column is the physical marking printed on the capacitor body (or listed in your BOM). The first two digits in the 'Significant Digits' column represent the base number. The 'Multiplier' column dictates how many zeros to append to that base number to get the raw Picofarads (pF). From there, you can read across to find the equivalent Nanofarads (nF) and Microfarads (µF). This coding system is standardized under IEC 60062 and EIA RS-198.
| 3-Digit Code | Significant Digits | Multiplier (pF) | Picofarads (pF) | Nanofarads (nF) | Microfarads (µF) |
|---|---|---|---|---|---|
| 101 | 10 | × 10 | 100 pF | 0.1 nF | 0.0001 µF |
| 102 | 10 | × 100 | 1,000 pF | 1 nF | 0.001 µF |
| 103 | 10 | × 1,000 | 10,000 pF | 10 nF | 0.01 µF |
| 104 | 10 | × 10,000 | 100,000 pF | 100 nF | 0.1 µF |
| 105 | 10 | × 100,000 | 1,000,000 pF | 1,000 nF | 1.0 µF |
| 224 | 22 | × 10,000 | 220,000 pF | 220 nF | 0.22 µF |
| 473 | 47 | × 1,000 | 47,000 pF | 47 nF | 0.047 µF |
| 474 | 47 | × 10,000 | 470,000 pF | 470 nF | 0.47 µF |
Bookmark-Friendly Quick-Jump: The Most Queried Codes
If you are troubleshooting a board or doing a quick BOM check, these are the five codes you will encounter 90% of the time on the bench:
- 104 (0.1 µF / 100 nF): The universal decoupling capacitor for digital ICs. Usually found in 0402 or 0603 packages right next to VCC pins.
- 105 (1.0 µF): Common for bulk bypass and low-frequency filtering. Watch out for DC bias derating on this one if used on a 5V or 12V rail.
- 103 (0.01 µF / 10 nF): Standard high-frequency decoupling, often paired in parallel with a 104 to lower the overall impedance profile.
- 474 (0.47 µF): Frequently used in audio coupling circuits and timing networks.
- 224 (0.22 µF): Common in analog filters and active oscillator feedback loops.
DC Bias & Temperature Derating: What the Chart Cannot Tell You
The standard capacitance chart assumes ideal conditions: 0V DC bias and 25°C ambient. In reality, Class II ceramic dielectrics (like X7R and X5R) exhibit severe capacitance loss when DC voltage is applied. This is known as DC bias derating. The physical mechanism is the alignment of ferroelectric domains in the barium titanate dielectric; as the electric field increases, the material's permittivity drops.
Which column applies to your installation? When looking at a manufacturer's derating matrix, the column you must read is dictated by your dielectric class. C0G (NP0) is Class I and exhibits virtually zero DC bias or temperature shift. X7R and X5R are Class II and require heavy derating. Y5V is Class III and should generally be avoided in precision or power circuits due to extreme temperature instability.
| Dielectric Code | Temp Range | Typical Cap Shift at Rated Voltage | Typical Cap Shift at Max Temp | Best Application |
|---|---|---|---|---|
| C0G (NP0) | -55 to 125°C | 0% (No shift) | ±30 ppm/°C | RF, precision timing, filters |
| X7R | -55 to 125°C | -40% to -70% | ±15% | General bypass, bulk decoupling |
| X5R | -55 to 85°C | -50% to -80% | ±15% | Consumer electronics, low-cost bulk |
| Y5V | -30 to 85°C | -70% to -90% | +22% / -82% | Non-critical coupling (avoid if possible) |
How derating rows modify the base value: To find your effective capacitance, multiply the base value from Table 1 by the percentage remaining from the manufacturer's DC bias curve. For example, if your 12V buck converter requires 10µF of output capacitance, and you select a 10µF X5R part that retains only 35% of its value at 12V, your effective capacitance is 3.5µF. To actually get 10µF at 12V, you must either select a 22µF or 47µF nominal part, step up to a larger case size (like 1206 or 1210, which have thicker dielectric layers and derate less), or parallel multiple smaller capacitors.
What the Standard Chart Misses: ESR, ESL, and Ripple Limits
While the capacitance chart gives you the nominal energy storage value, it is entirely blind to the parasitic elements that dictate high-frequency performance and thermal limits. When sourcing components from suppliers like Murata or KEMET, you must cross-reference the datasheet for the following parameters:
- Equivalent Series Resistance (ESR): Dictates how much heat the capacitor will generate under AC ripple current. A 100µF polymer aluminum capacitor might have an ESR of 5mΩ, while a 100µF MLCC might be 3mΩ. Lower ESR means less self-heating and better high-frequency noise suppression.
- Equivalent Series Inductance (ESL): Limits the capacitor's ability to respond to fast transient load steps. ESL is primarily driven by package geometry. An 0402 package has significantly lower ESL than a 1206 package, which is why high-speed FPGA power rails use banks of tiny 0201 or 0402 capacitors rather than a few large ones.
- Ripple Current Rating: Unlike electrolytic capacitors, MLCC datasheets rarely specify a hard ripple current limit. Instead, you must calculate the allowable ripple based on the part's maximum temperature rise (usually ΔT = 20°C) and its ESR at your switching frequency.
- Piezoelectric Microphonics: Class II MLCCs (X7R/X5R) are piezoelectric. They will physically vibrate and generate audible noise ('singing capacitors') when subjected to high AC ripple, and conversely, they will generate voltage spikes when the PCB is mechanically flexed. If your circuit is in an audio path or a high-vibration environment, you must use C0G dielectrics or polymer capacitors instead.
Keep this guide bookmarked at your workbench. The next time you reach for a '105' capacitor to filter a 12V rail, you will know exactly why you need to check the DC bias curve before soldering it down.
