220 capacitor value
22 pF
22 pF · 0.022 nF · 0.000022 µF
| Marked code | 220 |
| Picofarads | 22 pF |
| Nanofarads | 0.022 nF |
| Microfarads | 0.000022 µF |
| Farads | 2.20e-11 F |
Reading the code
The three digits are not a part number. The first two are the value in picofarads and the third says what to do with them:
22 × 100 = 22 pF
So 220 is 22 followed by 0 zeros: 22 pF. The code is always in picofarads even when the part is sold in microfarads, which is the whole difficulty with it — a capacitor marked 220 is stocked as 0.000022 µF and the two numbers look nothing alike.
What 22 pF does at frequency
A capacitor's opposition to a signal is its reactance, 1 ÷ (2πfC), and it falls as the frequency rises. Over the range of frequencies a circuit can put across it, a 22 pF part covers several orders of magnitude:
| Frequency | Reactance |
|---|---|
| 50 Hz — mains | 144.69 MΩ |
| 1 kHz — audio | 7.23 MΩ |
| 100 kHz — switching | 72.34 kΩ |
| 10 MHz — RF | 723.43 Ω |
Ten times the frequency is a tenth of the reactance, every time — which is why choosing a decoupling capacitor is really choosing the frequency band you want it to be low-impedance across, and why boards carry several sizes in parallel rather than one large one.
The letter after the number
A code like 220K carries a tolerance letter. It is not part of the value:
| Letter | Tolerance | 22 pF means |
|---|---|---|
220J | ±5% | 20.9 pF to 23.1 pF |
220K | ±10% | 19.8 pF to 24.2 pF |
220M | ±20% | 17.6 pF to 26.4 pF |
220Z | +80% / −20% | 17.6 pF to 39.6 pF |
A Z is worth knowing about. +80%/−20% is a real tolerance on cheap high-permittivity ceramics, and it means a part marked 220Z can legitimately be anything from 17.6 pF to 39.6 pF. Those go in decoupling positions where only the rough size matters, never in a timing or filter position.
Where 22 pF turns up
Tens of picofarads is the crystal load range: the two capacitors either side of a quartz crystal that set it oscillating at its marked frequency. Also RF tuning and the compensation capacitor round a fast op-amp.
Frequently asked questions
What is the value of a 220 capacitor?
22 pF — 22 pF · 0.022 nF · 0.000022 µF. The first two digits are the value in picofarads and the third is how many zeros follow, so 220 is 22 followed by 0 zeros = 22 pF.
What is a 220 capacitor in µF?
0.000022 µF. Going from picofarads to microfarads is six decimal places, which is where most of the confusion with these codes comes from — 22 pF, 0.022 nF and 0.000022 µF are the same capacitor written three ways.
What does the letter after 220 mean?
Tolerance. 220K is ±10%, 220J is ±5% and 220M is ±20% — so a 220K is anywhere from 19.8 pF to 24.2 pF and still in specification. A Z means +80%/−20%, which is not a mistake: some ceramic dielectrics really are that loose.
What is the impedance of a 220 capacitor at 1 kHz?
7.23 MΩ. Reactance is 1 ÷ (2πfC), so it falls as the frequency rises: the same part is 72.34 kΩ at 100 kHz and 723.43 Ω at 10 MHz.
Nearby codes
- 270 capacitor — 27 pF
- 330 capacitor — 33 pF
- 390 capacitor — 39 pF
- 470 capacitor — 47 pF
- 560 capacitor — 56 pF
- 680 capacitor — 68 pF
- 820 capacitor — 82 pF
- 101 capacitor — 100 pF
- 121 capacitor — 120 pF
- 151 capacitor — 150 pF