Q: What is the operational role of power inductors in Class-D amplifier circuits?
A: In Class-D audio amplification systems, power inductors perform critical filtering functions through these primary mechanisms:
LC Filter Core Function
Collaborating with capacitors to form:
Key selection parameters for modern high-performance designs:
These magnetics enable Class-D amplifiers to achieve:
✓ >90% power conversion efficiency
✓ THD+N <0.005% @20hz-20kHz
✓ 85°C ambient temperature operation
✓ MIL-STD-202G compliant vibration resistance
Typical applications: automotive infotainment, professional PA systems, and compact IoT audio solutions.
A: In Class-D audio amplification systems, power inductors perform critical filtering functions through these primary mechanisms:
LC Filter Core Function
Collaborating with capacitors to form:
- 2nd-order low-pass filter topology (typically 50-500kHz cutoff)
- 40-60dB attenuation of PWM carrier residue (300kHz-1MHz range)
- 90%+ suppression of harmonic distortion components
Key selection parameters for modern high-performance designs:
- Miniaturization: 1210 to 2520 case sizes with <1.2mm profile
- Efficiency Enhancement: <0.05Ω DCR at 3A load conditions
- Thermal Stability: Maintain stability from -40°C to +125°C
- Saturation Resilience: 20-30% headroom above peak current (I_sat ≥ 5A)
- EMI Mitigation: <5nH parasitic capacitance configuration
These magnetics enable Class-D amplifiers to achieve:
✓ >90% power conversion efficiency
✓ THD+N <0.005% @20hz-20kHz
✓ 85°C ambient temperature operation
✓ MIL-STD-202G compliant vibration resistance
Typical applications: automotive infotainment, professional PA systems, and compact IoT audio solutions.