# SMD-X1Y1 Series Safety Certified SMD Ceramic Capacitors (Class X1/Y1)

> Resin-molded SMD ceramic safety capacitors, Class X1/Y1, for EMI suppression. X1 760 VAC, Y1 500 VAC, 10–4,700 pF.

- Series code: SMD-X1Y1
- Product line: [Ceramic capacitors](https://www.songtian-ste.com/en/products/ceramic-capacitors/) › SMD safety and high-voltage capacitors
- Also listed in: [SMD components](https://www.songtian-ste.com/en/products/smd/)
- Approvals: VDE, ENEC
- Part numbers and datasheets on request
- Page: https://www.songtian-ste.com/en/products/ceramic-capacitors/smd-x1y1/
- Chinese version: https://www.songtian-ste.com/zh/products/ceramic-capacitors/smd-x1y1/
- [Ask AI about this series](https://www.songtian-ste.com/en/products/ceramic-capacitors/smd-x1y1/?ask=Help%20me%20choose%20a%20part%20from%20the%20STE%20SMD-X1Y1%20series.)

## Key specifications

| Parameter | Value |
| --- | --- |
| Safety class | X1 / Y1 (IEC 60384-14) |
| Rated voltage | X1 760 VAC · Y1 500 VAC |
| Capacitance | 10–4,700 pF |
| Package format | 3022 / 3222 / 3225 / 4522 |
| Approvals | CQC · VDE/ENEC · UL/cUL · IEC CB · KTL |

## Engineering details

### Overview

Resin-molded SMD ceramic safety capacitors, Class X1/Y1 to IEC 60384-14, for AC-line EMI suppression and primary-to-secondary coupling in low-profile power supplies. Rated X1 760 VAC / Y1 500 VAC, 10–4,700 pF, in four SMD package formats, 2.4–2.5 mm high. Operating temperature −40 °C to +125 °C.

#### Series features

- Class X1/Y1 to IEC 60384-14, for circuit positions that require reinforced insulation
- Body height 2.4–2.5 mm; flat terminals, no leads through the board
- Dielectric withstand 4 kVAC r.m.s. between terminals, 60 s
- Tape and reel, MSL 3, reflow solderable, for automated SMT assembly
- Flame-retardant epoxy molding to UL 94 V-0

#### Typical applications

- Line-to-earth (common-mode) noise suppression in server, industrial and appliance power supplies
- Primary-to-secondary coupling in switch-mode power supplies and AC converters
- Across-the-line (L–N) X1 suppression within the rated X1 voltage
- Low-profile power assemblies without through-hole leads

### Specifications

|   |   |
| --- | --- |
| Safety class | X1 / Y1 (IEC 60384-14) |
| Rated voltage | X1 760 VAC · Y1 500 VAC |
| Capacitance range | 10–4,700 pF |
| Package formats | 3022 · 3222 · 3225 · 4522 (STE format codes, not EIA chip sizes) |
| Operating temperature | −40 °C to +125 °C |
| Climatic category | 40/125/21 · flammability class B |
| Dielectrics | SL · Y5P · Y5U · Y5V |
| Capacitance tolerance | K ±10% · M ±20% |
| Dielectric withstand | 4 kVAC r.m.s. · 60 s |
| Insulation resistance | >10,000 MΩ at 500 VDC, 60 ±5 s |
| Moisture sensitivity | MSL 3 |
| Flammability | Epoxy molding to UL 94 V-0 |

### Variants

Ranges by dielectric, package and lead style within this series.

| Variant | Body dimensions | Capacitance | Dielectric | Lead / land pattern | Notes |
| --- | --- | --- | --- | --- | --- |
| 3022 | L 7.8 ±0.3 · W 5.4 ±0.2 · H 2.4 ±0.2 mm | 10–2,200 pF | SL · Y5P · Y5U · Y5V | a ≥8.0 · b 2.2 ±0.1 · c 3.6 ±0.1 mm | Shortest body, for low-profile, space-constrained layouts. |
| 3222 | L 8.1 ±0.3 · W 5.5 ±0.3 · H 2.5 ±0.3 mm | 10–2,200 pF | SL · Y5P · Y5U · Y5V | a 10.0 ±0.2 · b 2.2 ±0.2 · c 3.6 ±0.2 mm | General low-profile format with 10 mm land span. |
| 3225 | L 8.1 ±0.3 · W 6.0 ±0.3 · H 2.5 ±0.3 mm | 10–2,200 pF | SL · Y5P · Y5U · Y5V | a 10.0 ±0.2 · b 2.2 ±0.2 · c 3.6 ±0.2 mm | Wider body; covers the main 10–2,200 pF range. |
| 4522 | L 11.5 ±0.3 · W 6.1 max. · T 2.5 ±0.3 mm | 3,300–4,700 pF | Y5V | a 9.0 ±0.2 · b 1.7 ±0.2 · c 3.6 ±0.2 mm | Higher-capacitance format for 3.3 nF and 4.7 nF. |

### Selection guide

Choose the safety position first, then capacitance and dielectric, then the package format. Package codes are STE format names, not EIA chip sizes. Land pattern and approval scope: see the datasheet.

1. **Confirm the X1 or Y1 position**
   Define whether the capacitor sits line-to-line, line-to-earth or across an isolation barrier. A Y1 position requires the matching safety approval and insulation coordination in the end equipment.
2. **Define the voltage envelope**
   Include nominal AC voltage, switching overshoot, surges and abnormal conditions. The 4 kVAC withstand is a test condition, not a continuous working-voltage rating.
3. **Choose capacitance and dielectric**
   SL covers the lowest values with the highest stability; Y5P, Y5U and Y5V extend capacitance in that order. Capacitance change over temperature and tolerance: see the datasheet.
4. **Verify footprint and creepage**
   Use the body and land dimensions of the selected package. Recheck creepage and clearance on the assembled PCB, including pollution degree, coating and spacing to the chassis.
5. **Validate the assembly process**
   Handle the series as MSL 3, validate the reflow profile and observe the floor life after opening the bag. Confirm cleaning agents, coatings and potting compounds on the production assembly.

### Approvals & reliability

#### Approvals & qualifications

Approved ratings differ by agency.

| Agency | Standard | Certificate | Scope |
| --- | --- | --- | --- |
| CQC CQC | IEC 60384-14:2013 + AMD1:2016 | CQC24001446247 | SMD X1/Y1, 10–4,700 pF. Issued 2 Feb 2026, valid to 1 Feb 2031 subject to surveillance. |
| VDE, ENEC VDE / ENEC | IEC / EN IEC 60384-14:2023 | 40058861 | Rated voltage: X1 760 / 500 / 400 VAC; Y1 500 / 400 / 250 VAC |
| UL UL / cUL | UL / CSA 60384-14 | E530201 | Recognized component, USA and Canada. |
| IECEE CB IEC CB | IEC 60384-14:2023 | DE1-68874/B1 | CB Scheme test certificate |
| KTL KTL | KC 60384-1 / KC 60384-14 | SU03031-24001B | Rated voltage: Y1 250 VAC |

Each certificate covers the types and ratings listed on it.

#### Reliability tests

Test conditions and acceptance limits. Limits can vary by package and dielectric; see the datasheet.

| Test | Condition | Acceptance |
| --- | --- | --- |
| Damp heat, steady state | 40 ±2 °C · 90–95% RH · 500 ±12 h | No visible damage · ΔC within the specified limit · IR >5,000 MΩ · withstands 4 kVAC, 60 s |
| Damp heat with load | 40 ±2 °C · 90–95% RH · rated voltage · 500 ±12 h | No visible damage · electrical limits met after the test |
| Endurance | 125 °C · 1,000 h · test voltage with hourly impulse per datasheet | No visible damage · ΔC within ±20% · IR >5,000 MΩ · withstands 4 kVAC, 60 s |
| Rapid change of temperature | −40 °C ↔ +125 °C · five cycles | No visible damage · capacitance and dissipation factor within the limits of the dielectric |
| Resistance to soldering heat | Solder 260 +5/−0 °C · 10 ±1 s · after preconditioning | No visible damage · ΔC within ±10% · withstands 4 kVAC, 60 s |
| Vibration, board bending and shear | 10–55–10 Hz · 1.5 mm · 6 h; bend and 5 N shear test per package | No significant abnormality or terminal displacement; electrical drift within the specified limits |

### Design notes

#### Reflow and moisture handling

MSL 3. Store at ≤30 °C / 60% RH and use within six months of delivery. Complete soldering within 168 h after opening the moisture barrier bag. If floor life or storage time is exceeded, bake at 60 °C for 168 h. Reference reflow window: 230–260 °C for 10–30 s, preheat 170 °C max. Validate the production profile.

#### Working voltage and self-heating

Keep all steady-state and transient voltage components within the rated voltage. Keep the capacitor surface below the +125 °C operating limit, including self-heating from dielectric loss. For the applicable high-permittivity dielectrics, limit temperature rise to 20 °C at 25 °C ambient.

#### PCB land, flex and handling

Match the land pattern to the selected package. Do not move, tilt or load the body after soldering. Board flex, terminal misalignment and mechanical shock can damage the ceramic element or the termination.

#### Cleaning, coating and potting

Validate cleaning agents, adhesives, conformal coatings and potting resins on the actual assembly. Organic solvents and mismatched curing or thermal expansion can attack the epoxy or cause cracks during temperature cycling.

#### Dielectric-withstand testing

Use a 50/60 Hz sinusoidal source, secure the terminals and ramp up from near zero. Repeated hipot testing can damage the component. Do not return parts used for hipot verification to production stock.

#### Fail-safe design

A damaged safety capacitor can fail short. Provide fusing or another automatic protective function. Contact STE before use in life-support, transportation, power-plant control or other applications where failure has severe consequences.

## Datasheets & approval documents

- [Technical document: SMD-X1Y1 series SMD molded EMI suppression safety capacitors, package 3022 (2025-03)](https://www.songtian-ste.com/documents/source-cn/smd/%E5%A1%91%E5%B0%81%E8%B4%B4%E7%89%87%E6%8A%97%E5%B9%B2%E6%89%B0%E5%AE%89%E8%A7%84%E7%94%B5%E5%AE%B9%E5%99%A8%EF%BC%88SMD-X1Y1%E7%B3%BB%E5%88%97%203022%EF%BC%89%2025.03.22.pdf) — PDF · Chinese · 2025-03 · 576 KB
- [Technical document: SMD-X1Y1 series SMD molded EMI suppression safety capacitors, package 3222 (2025-03)](https://www.songtian-ste.com/documents/source-cn/smd/%E5%A1%91%E5%B0%81%E8%B4%B4%E7%89%87%E6%8A%97%E5%B9%B2%E6%89%B0%E5%AE%89%E8%A7%84%E7%94%B5%E5%AE%B9%E5%99%A8%EF%BC%88SMD-X1Y1%E7%B3%BB%E5%88%97%203222%EF%BC%89%2025.03.22.pdf) — PDF · Chinese · 2025-03 · 556 KB
- [Technical document: SMD-X1Y1 series SMD molded EMI suppression safety capacitors, package 3225 (2025-03)](https://www.songtian-ste.com/documents/source-cn/smd/%E5%A1%91%E5%B0%81%E8%B4%B4%E7%89%87%E6%8A%97%E5%B9%B2%E6%89%B0%E5%AE%89%E8%A7%84%E7%94%B5%E5%AE%B9%E5%99%A8%EF%BC%88SMD-X1Y1%E7%B3%BB%E5%88%97%203225%EF%BC%89%2025.03.22.pdf) — PDF · Chinese · 2025-03 · 556 KB
- [Technical document: SMD-X1Y1 series SMD molded EMI suppression safety capacitors, package 4522 (2025-04)](https://www.songtian-ste.com/documents/source-cn/smd/%E5%A1%91%E5%B0%81%E8%B4%B4%E7%89%87%E6%8A%97%E5%B9%B2%E6%89%B0%E5%AE%89%E8%A7%84%E7%94%B5%E5%AE%B9%E5%99%A8%EF%BC%88SMD-X1Y1%E7%B3%BB%E5%88%97%204522%EF%BC%89%2025.04.25.pdf) — PDF · Chinese · 2025-04 · 579 KB
- [Certificate: SMD safety ceramic capacitor international certificates (2026-03)](https://www.songtian-ste.com/documents/source-cn/current/smd-safety-ceramic-certificates-2026-03.pdf) — PDF · Chinese / English · 2026-03 · 3.5 MB

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