Understanding X1 Class Film Capacitors: Why jb’s JFT Series Is a Reliable EMI Filter Choice
In AC applications where EMI suppression, safety compliance, and compact design are essential, choosing the right Class X1 film capacitor is critical to ensure stability and regulatory compatibility. The jb JFT series is built for these needs—delivering consistent electrical performance, compact dimensions, and full X1-class certification.
What is a Class X1 Capacitor?
X1 capacitors are safety-certified components used across the line (L–N) to suppress differential-mode interference in AC circuits. As defined by IEC 60384-14:
- Withstand impulses up to 4kV, suitable for industrial and commercial-grade environments.
- Built with fail-safe, self-healing construction for stability under harsh electrical stress.
Applications include switching power supplies, motor drives, HVAC controls, and AC line filtering.
Key Features of jb JFT X1 Film Capacitors
| Specification | Details |
|---|---|
| Capacitor Class | X1 (Interference Suppression) |
| Rated Voltage | 300VAC / 440VAC |
| Capacitance Range | 0.0022µF to 4.7µF |
| Capacitance Tolerance | ±10% |
| Operating Temperature | −55°C to +105°C |
| Dissipation Factor (1kHz) | Max. 0.001 |
| Insulation Resistance | ≥15,000 MΩ (C ≤ 0.33µF) |
| Package Size | As small as 13 × 11 × 5 mm |
Typical Applications
- AC input EMI filters
- Switched-mode power supplies (SMPS)
- LED driver circuits
- HVAC control systems
- Industrial automation devices
- Smart sockets, adapters, and AC-powered appliances
Engineered for long-term stability under fluctuating AC voltage, making them ideal for mission-critical use cases.
Why Engineers Prefer the JFT Series
| Feature | JFT X1 Capacitor | Standard Ceramic Capacitor |
|---|---|---|
| EMI Suppression | Excellent | Moderate |
| Safety Certification (X1) | Yes | No |
| Surge Voltage Handling | Up to 4kV | Limited |
| Fail-Safe Mechanism | Self-healing | Short-circuit risk |
| Long-Term Reliability | High | Medium |
With excellent electrical properties, compact design, and international compliance, the JFT series is a preferred choice for engineers building high-performance, safety-compliant AC products.

