Coilcraft has introduced the DFC1210 series, a family of automotive-grade common mode chokes designed for high-frequency noise suppression on power lines in a compact chip-style footprint.
The series targets designers who need to meet CISPR 25 Class 5 EMC requirements while keeping board space and component count under control in modern vehicle electronics.
Key features and benefits
- Compact 1210 footprint: 3.25 x 2.67 x 2.8 mm, suited to dense automotive ECU and power-line filter layouts
- CISPR 25 Class 5 optimization: engineered for high-frequency common mode noise suppression across the 30 MHz to 3 GHz range referenced in the manufacturer announcement
- Wirewound surface mount construction: gives broadband impedance behavior that stays consistent across frequency, DC bias current, and temperature
- AEC-Q200 qualified: passed the automotive stress-test qualification, indicating the component has been validated for the temperature cycling, vibration, and humidity conditions typical of automotive electronics
- High current capability: rms current ratings up to 1.7 A at 25°C depending on part number, according to the manufacturer datasheet
- Wide operating range: -40°C to +125°C ambient temperature range with rated Irms current
Technical highlights
The DFC1210 series is available in three standard inductance values, each with two lines (differential pair configuration). Electrical specifications are measured at 25°C according to the manufacturer datasheet.
| Part number | Common mode impedance (typ, @ 100 MHz) | Inductance | Irms @ 25°C | DCR max | Isolation voltage |
|---|---|---|---|---|---|
| DFC1210-681 | 150 Ω | 0.68 µH | 1.7 A | 75 mΩ | 250 Vrms |
| DFC1210-122 | 275 Ω | 1.2 µH | 1.7 A | 90 mΩ | 250 Vrms |
| DFC1210-182 | 425 Ω | 1.8 µH | 1.5 A | 105 mΩ | 250 Vrms |
Inductance is measured at 100 kHz, 0.1 Vrms, 0 A DC, with a tolerance of -30%/+50% per the manufacturer datasheet. Isolation voltage is rated at 353 VDC / 250 Vrms for one minute (hipot) between primary and secondary windings. The core material is ferrite, and the termination finish is RoHS-compliant matte tin over nickel over silver-palladium-glass frit, a construction intended to support reliable solder joints through multiple reflow cycles. Moisture Sensitivity Level is rated 1, meaning the parts have unlimited floor life below 30°C and 85% relative humidity before mounting — a practical consideration for EMI filter assembly lines that batch-stage automotive boards.
Typical applications
Common mode chokes of this type are used wherever a power line needs high-frequency noise suppression without adding bulk to the board. Based on the manufacturer’s stated qualification and performance profile, suitable use cases include automotive ECUs, sensor modules, and power distribution lines subject to CISPR 25 testing.
- Automotive electronic control units (ECUs) and body control modules
- DC power-line filtering in infotainment and driver-assistance subsystems
- Sensor and actuator interface lines requiring EMC compliance
- Compact automotive power converters where board area is constrained
Application fit
CISPR 25 defines conducted and radiated emission limits for automotive electrical and electronic components, and Class 5 represents one of the tighter limit classes in that standard. A common mode choke optimized for this class is intended to attenuate noise currents that flow in the same direction on both conductors of a power line pair — a noise mode that ordinary inductors alone do not effectively suppress, since it requires a component wound to present high impedance to common mode currents while allowing differential (signal or power) current to pass largely unaffected.
Design-in notes for engineers
- Confirm the required CISPR 25 subclass and frequency range for the target vehicle platform before selecting a specific DFC1210 part number, since impedance and attenuation vary by inductance value
- Check DC bias current against the application’s actual line current; Irms ratings decrease at 85°C and 125°C ambient, so thermal margin should be verified against the manufacturer datasheet
- Use the DCR-at-temperature relationship to estimate power dissipation and resulting temperature rise in the final enclosure, rather than relying solely on the 25°C DCR value
- AEC-Q200 qualification supports automotive reliability requirements, but final qualification and design release should still follow the OEM’s own component approval process
- Reflow and washing limits (three 40-second reflows at +260°C, aqueous-wash compatibility per MIL-STD-202 Method 215) should be checked against the actual assembly process
- For layouts with tight EMC margins, pair choke selection with board-level voltage derating practices on nearby capacitors to avoid re-introducing noise coupling paths
Further reading
Source
This article is based on a manufacturer press release and product page from Coilcraft describing the DFC1210 series of automotive-grade common mode chokes. Design engineers should consult the current manufacturer datasheet and documentation before finalizing component selection or design release, as specifications may be updated over time.
