220 nF capacitor (0.22 µF)
A 220 nF capacitor is the same as 0.22 µF or 220,000 pF. On ceramic and film parts it is printed as the code 224; schematics often write 220n.
How a 220 nF capacitor is marked
| Style | Marking | Where you see it |
|---|---|---|
| 3-digit code | 224 | Ceramic discs, multilayer ceramics, film capacitors |
| Code + tolerance | 224J · 224K · 224M | ±5% · ±10% · ±20% |
| Code + voltage | 1H224K · 2A224J | 50 V · 100 V film capacitors |
| IEC 60062 letter code | 220n | Schematics, European parts (the letter is the decimal point) |
| Plain value | .22 (µF) | Older US parts and electrolytics — bare decimals are µF |
| SMD (0402–1206) | usually unmarked | Check the reel label or measure with an LCR meter |
220 nF in every unit
| Picofarads | 220,000 pF |
|---|---|
| Nanofarads | 220 nF |
| Microfarads | 0.22 µF |
| Farads | 2 × 10^-7 |
Reactance of 220 nF
A capacitor's opposition to AC falls as frequency rises: XC = 1 ÷ (2π f C). This tells you whether 220 nF passes or blocks a signal — a decoupling capacitor needs a low reactance at the noise frequency, a coupling capacitor at the lowest signal frequency.
| Frequency | Reactance XC |
|---|---|
| 50 Hz | 14.5 kΩ |
| 60 Hz | 12.1 kΩ |
| 1 kHz | 723 Ω |
| 10 kHz | 72.3 Ω |
| 100 kHz | 7.23 Ω |
| 1 MHz | 0.723 Ω |
| 10 MHz | 0.0723 Ω |
Real capacitors stop behaving like ideal ones above their self-resonant frequency, which depends on the package and lead length, so treat the high-frequency rows as an upper bound on performance.
RC time constant and filter corner with 220 nF
With a resistor R, the capacitor charges to 63% in one time constant τ = R × C and to over 99% in 5τ. The same pair makes a first-order low-pass or high-pass filter with corner frequency fc = 1 ÷ (2π R C).
| Resistor | τ = RC | 5τ (≈ full charge) | Corner fc |
|---|---|---|---|
| 100 Ω | 22 µs | 110 µs | 7.23 kHz |
| 1 kΩ | 220 µs | 1.1 ms | 723 Hz |
| 10 kΩ | 2.2 ms | 11 ms | 72.3 Hz |
| 100 kΩ | 22 ms | 110 ms | 7.23 Hz |
Choosing a 220 nF capacitor
| Usual dielectric | X7R ceramic, polyester or polypropylene film |
|---|---|
| Common voltage ratings | 25–275 V AC |
| Neighbouring E6 values | 68 nF, 100 nF, 150 nF, 330 nF, 470 nF, 680 nF |
220 nF appears both as a ceramic decoupling capacitor and as an X2-rated film capacitor across mains in power supplies and capacitive droppers. Those mains parts must carry an X2 safety rating — never substitute an ordinary ceramic marked 224 across 230 V or 120 V mains.
FAQ
What is the code for a 220 nF capacitor?
224. The first two digits (22) are picofarads and the third (4) is the number of zeros: 220,000 pF. In IEC letter notation it is written 220n.
Is 220 nF the same as 0.22 µF?
Yes. 220,000 pF = 220 nF = 0.22 µF; they are three names for the same capacitance.
What is the reactance of a 220 nF capacitor?
Xc = 1 ÷ (2π × f × C). At 1 kHz a 220 nF capacitor has 723 Ω; at 50 Hz 14.5 kΩ.
What cutoff frequency does 220 nF give with 10 kΩ?
fc = 1 ÷ (2π × 10 kΩ × 220 nF) = 72.3 Hz, and the time constant τ = R × C = 2.2 ms.