Sendust Toroidal Core Differential Mode Chokes – High Current, Low Noise, Excellent DC Bias

Sendust toroidal core inductors represent a high-performance solution for power supply designers seeking effective differential-mode noise suppression under conditions of high ripple current. Engineered to deliver an optimal balance of electrical performance, thermal and magnetic stability, and cost-efficiency, these differential-mode chokes are widely deployed in AC line filtering, DC–DC converter output stages, electromagnetic interference (EMI) line filters, and power factor correction (PFC) circuits.

Specifications

Operating Frequency Range: 8 kHz – 1 MHz

Rated Current Range: 0.05 A – 2000 A

Operating Temperature Range: −40 °C to +125 °C

Storage Temperature Range: −25 °C to +85 °C

Storage Humidity Range: 30 % – 95 % RH

Outer Diameter Range: 6 mm – 60 mm

Core Material and Key Technical Advantages

● Sendust (Fe–Si–Al) alloy core: Characterized by low core loss, high saturation flux density (~1.35 T), and superior DC bias handling—enabling stable inductance under substantial DC superposition.

● Toroidal geometry: Provides a fully closed magnetic path, minimizing stray magnetic fields and significantly reducing EMI radiation and coupling.

● Acoustically silent operation: No perceptible audible noise across the full operational frequency and load range, supporting noise-sensitive applications.

● Exceptional DC bias stability: Maintains >90 % of nominal inductance at rated saturation current, ensuring predictable filter behavior under dynamic load conditions.

● Broad current scalability: Covers applications from low-power signal conditioning (50 mA) to high-current industrial PFC and busbar-integrated systems (2000 A).

Typical Applications

● AC Line Inductors: Used in active and passive PFC stages and harmonic mitigation networks.

● Output Filter Inductors: Integrated into buck, boost, and flyback topologies for smoothing switched DC outputs.

● EMI Line Filters: Employed as differential-mode chokes in conducted EMI suppression per CISPR 22/32 and EN 55032 standards.

● PFC Chokes: Specifically optimized for continuous-conduction-mode (CCM) and transition-mode (TM) boost PFC converters.