# MLCC Dielectric Class and Temperature Code Reference > Source: https://netray.co/tools/mlcc-dielectric-class-temperature-code-reference > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Decode ceramic capacitor dielectric codes into temperature range and capacitance change, and see which codes are interchangeable in sourcing. ## Category electronics ## Industry Electronics Manufacturing ## Audience - Electronics buyer - Component engineer - Design engineer ## Tool **Kind:** worksheet **Mode:** reference **Columns:** #### Code **Key:** code **Type:** text #### Class **Key:** eia **Type:** text #### Operating range **Key:** range **Type:** text #### Capacitance change over range **Key:** change **Type:** text #### Meaning for sourcing **Key:** meaning **Type:** text **Rows:** **Code:** C0G **Eia:** Class I **Range:** -55 to +125 deg C **Change:** 0 +/-30 ppm/deg C **Meaning:** Very stable, low loss; used for timing, filters and RF. Often listed as NP0. **Code:** U2J **Eia:** Class I **Range:** -55 to +125 deg C **Change:** -750 +/-120 ppm/deg C **Meaning:** Intentional negative temperature coefficient used to compensate other parts. **Code:** X7R **Eia:** Class II **Range:** -55 to +125 deg C **Change:** +/-15 % **Meaning:** General purpose decoupling and bypass; capacitance falls with DC bias. **Code:** X7S **Eia:** Class II **Range:** -55 to +125 deg C **Change:** +/-22 % **Meaning:** Looser than X7R, higher volumetric efficiency. **Code:** X7T **Eia:** Class II **Range:** -55 to +125 deg C **Change:** +22 / -33 % **Meaning:** Wider drift for higher capacitance in small bodies. **Code:** X8R **Eia:** Class II **Range:** -55 to +150 deg C **Change:** +/-15 % **Meaning:** Automotive under hood and high temperature designs. **Code:** X6S **Eia:** Class II **Range:** -55 to +105 deg C **Change:** +/-22 % **Meaning:** Common for dense mobile decoupling where 105 deg C is enough. **Code:** X5R **Eia:** Class II **Range:** -55 to +85 deg C **Change:** +/-15 % **Meaning:** Consumer and indoor equipment; not a drop in for 125 deg C designs. **Code:** Y5V **Eia:** Class II **Range:** -30 to +85 deg C **Change:** +22 / -82 % **Meaning:** Large capacitance swing; avoid where value matters. **Code:** Z5U **Eia:** Class II **Range:** +10 to +85 deg C **Change:** +22 / -56 % **Meaning:** Narrow range, low cost bulk decoupling in older designs. **Code:** Letter 1: X **Eia:** Decoder **Range:** Low limit -55 deg C **Change:** n/a **Meaning:** First letter sets the lowest operating temperature. **Code:** Letter 1: Y **Eia:** Decoder **Range:** Low limit -30 deg C **Change:** n/a **Meaning:** First letter sets the lowest operating temperature. **Code:** Letter 1: Z **Eia:** Decoder **Range:** Low limit +10 deg C **Change:** n/a **Meaning:** First letter sets the lowest operating temperature. **Code:** Digit 2: 5 **Eia:** Decoder **Range:** High limit +85 deg C **Change:** n/a **Meaning:** Second character sets the highest operating temperature. **Code:** Digit 2: 6 **Eia:** Decoder **Range:** High limit +105 deg C **Change:** n/a **Meaning:** Second character sets the highest operating temperature. **Code:** Digit 2: 7 **Eia:** Decoder **Range:** High limit +125 deg C **Change:** n/a **Meaning:** Second character sets the highest operating temperature. **Code:** Digit 2: 8 **Eia:** Decoder **Range:** High limit +150 deg C **Change:** n/a **Meaning:** Second character sets the highest operating temperature. **Code:** Letter 3: R **Eia:** Decoder **Range:** n/a **Change:** +/-15 % **Meaning:** Third letter sets the allowed capacitance change. **Code:** Letter 3: S **Eia:** Decoder **Range:** n/a **Change:** +/-22 % **Meaning:** Third letter sets the allowed capacitance change. **Code:** Letter 3: T **Eia:** Decoder **Range:** n/a **Change:** +22 / -33 % **Meaning:** Third letter sets the allowed capacitance change. **Code:** Letter 3: V **Eia:** Decoder **Range:** n/a **Change:** +22 / -82 % **Meaning:** Third letter sets the allowed capacitance change. **Notes:** Class II and III values are measured without DC bias. In use, applied voltage reduces effective capacitance, sometimes by half or more on small high-value parts, so size the part from the manufacturer's DC bias curve. Dielectric substitution should always go through engineering approval. ## Content **Intro:** A ceramic capacitor line on a BOM often carries a dielectric code like X7R or C0G, and the code decides whether a substitute is safe. This reference decodes each code into its temperature range and allowed capacitance drift, and shows how the three characters are built. **Sections:** #### How to use the reference **Body:** Search the code from your BOM or from a distributor listing. The top block lists the codes you will meet most often, and the bottom block shows how to decode any three character code yourself. Use it before accepting an alternate: an engineer can tell at a glance whether an X5R is being offered for an X7R requirement. **Bullets:** - Search a code such as X7R or the letter you want decoded - Compare operating range before capacitance change - Export the table to attach to an alternate approval record #### How the EIA code is read **Body:** Class II and III capacitors use three characters. The first letter is the low temperature limit, the digit is the high temperature limit, and the last letter is the maximum capacitance change over that range. So X7R means -55 to +125 deg C with no more than +/-15 percent change. Class I parts such as C0G use a different scheme that states a temperature coefficient in parts per million per degree, which is why they are far more stable. #### What it means when approving an alternate **Body:** A part with a wider operating range and equal or tighter capacitance change can usually replace a lesser one, so X7R can often stand in for X5R but not the reverse. C0G cannot be replaced by a Class II part in a filter or timing circuit, because the capacitance will shift with temperature and bias. Voltage rating, case size, and DC bias behaviour also matter, so treat the code as one filter, not the full answer. #### Common mistakes **Body:** Buyers sometimes treat Y5V as a cheaper X7R. It is not: its capacitance can fall by more than 80 percent at temperature extremes. Another error is ignoring DC bias, which can make a 10 uF part in a small body deliver only a few microfarads at the working voltage. Record dielectric, voltage and size together in your ERP item description so searches return true equivalents. **Cta:** If alternate capacitor approvals live in email threads, we can build a private agent over your ERP and engineering documents that checks dielectric and rating before an alternate is proposed. **Faq:** #### Is NP0 the same as C0G? **Answer:** In practice yes. NP0 is the older name for the Class I dielectric that EIA calls C0G, with a temperature coefficient near zero. Manufacturers use both labels for the same behaviour. #### Can I replace X5R with X7R? **Answer:** Often yes, because X7R covers a wider temperature range with the same +/-15 percent change. Confirm voltage rating, case size, DC bias curve and height, and get engineering sign off. #### Why does my 10 uF capacitor measure much lower in circuit? **Answer:** Class II ceramics lose effective capacitance as DC voltage rises. Small bodies and high capacitance values lose the most, so the datasheet bias curve shows what you really get at the rail voltage. #### Should I use Y5V in new designs? **Answer:** It is rarely a good idea. Its capacitance swing is very large, and most designers choose X5R, X6S or X7R when the value must hold. Check with the design engineer before accepting it as an alternate. ## Search terms x7r vs x5r, c0g vs np0, mlcc dielectric codes, capacitor temperature code, y5v capacitor, x7r temperature range, ceramic capacitor dielectric types, eia temperature characteristic codes --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json