FAQ

1.Q: What is the core difference between power inductors and high-frequency inductors? How to select appropriately?

A: Power inductors (e.g., magnetically shielded inductors) prioritize high-current handling and low loss (temperature rise ≤40°C), commonly used in power conversion circuits. High-frequency inductors emphasize high Q factor and high self-resonant frequency (SRF 100 MHz), primarily deployed in RF circuits for impedance matching. Selection must align with actual current requirements, operating frequency range, and EMI compliance standards.

2.Q: Is a higher inductor Q factor always better? What factors affect Q?

A: Q factor represents quality factor. In high-frequency applications, high Q (80) is often required; however, in power circuits, rated current and inductor losses are more critical. Q is jointly influenced by coil material (e.g., copper purity), core losses (ferrite vs. alloy powder), and operating frequency.

3.Q: How do inductors address EMC issues in new-energy vehicle motor controllers?

A: Common-mode chokes (impedance 1 kΩ @ 100 kHz) suppress motor-generated noise. Design must comply with ISO 7637-2. CODACA automotive-grade Common Mode Choke - VSTCB and VSTP series - are recommended.

4.Q: Does ±10% or ±5% inductance tolerance significantly impact circuit performance for high current power inductors?

A: Tolerance requirement depends on application: ±10% is acceptable for digital amplifier output-stage filtering; RF matching  demands ≤ ±5%.

5.Q: How to calculate whether temperature rise of an inductor in a Buck circuit exceeds specification?

A: Temperature rise ΔT ≈ (I² × ACR) / (thermal resistance θja × surface area).

6.Q: Can CODACA  provide inductor samples and free test reports?

A: Yes — up to five standard items can be shipped within 48 hours (subject to stock availability), including LCR test data (inductance, Q factor, SRF) and thermal-rise curves. Apply now for samples.

7.Q: What are the lead time and minimum order quantity (MOQ) for CODACA custom inductors?

A: For standard products in stock: no MOQ and delivery as fast as 48 hours. For out-of-stock items, MOQ must be confirmed with CODACA sales.

8.Q: What new design requirements do wide-band gap semiconductors (SiC/GaN) impose on high current power inductors?

A: Two key challenges arise:

① Higher switching frequency — Requires low-loss, high-frequency core materials and optimized coil/structural design. CODACA ’s CSBA series delivers compact, low-loss high current power inductors specifically engineered for GaN applications.

② Higher dV/dt — Necessitates enhanced inter-layer insulation (dielectric strength 800 V). CODACA is launching a new high-voltage product line.

9.Q: How to choose between magnetically shielded and non-shielded inductors?

A: Shielded inductors offer superior EMI performance (radiated emissions reduced by ~20 dB) but carry a modest cost premium. Non-shielded types provide clear cost advantages and suit price-sensitive, low-switching-frequency applications. Selection must balance cost against EMC requirements.

10.Q: Do CODACA  inductors comply with automotive AEC-Q200 standard?

A: All CODACA automotive-grade products are AEC-Q200 certified (operating temperature grades: 125°C, 155°C, and 170°C) and support PPAP documentation delivery.

11.Q: What are the key selection criteria for boost inductors in photovoltaic inverters?

A: Critical requirements include:

① High DC bias tolerance (saturation current 30 A);

② Low high-frequency loss (using ferrite or metal powder cores);

③ Optimized thermal base plate design. CODACA’s CPEX, CPRX, and CPRA series are PV-optimized for 98% efficiency.

12.Q: Is lower DCR always better for power inductors?

A: Not universally. While low DCR minimizes copper loss in most Buck DC-DC converters, certain impedance-matching applications require specific DCR values. CODACA's flat-wire process reduces DCR by up to 30% versus round-wire equivalents.

13.Q: How do Common Mode Choke suppress EMI noise?

A: Common Mode Choke suppress common-mode noise via unique electromagnetic structure: when common-mode noise flows through both windings, magnetic fields add constructively, driving the core into rapid saturation and presenting high impedance -thereby blocking common-mode current propagation.

14.Q: How to select automotive-grade molded inductors for on-board chargers (OBC)?

A: Key criteria: wide operating temperature, high saturation current (to withstand transient peaks), low DCR (minimizing losses), high voltage rating, and AEC-Q200 certification. CODACA 's automotive high current power inductors feature ultra-low-loss core material, saturation current up to 422 A, ultra-low DCR, 800 V working voltage, and enhanced vibration resistance — ideal for high-voltage OBC fast-charging modules.

15.Q: Which power inductors are recommended for industrial servo drives?

A: CODACA 's CSEG series molded power inductors are optimal by using low-loss alloy powder, they deliver minimal inductance loss across a broad frequency range (100 kHz – 5 MHz), significantly improving power conversion efficiency.

16.Q: What inductor types are commonly used in automotive electronics, and what special requirements apply?

A: Widely adopted types include high current power inductors, molding power choke, and common mode choke. Special requirements encompass full trace-ability, zero-defect (0 PPM) commitment, PPAP support, robust vibration/shock resistance, high reliability (AEC-Q200 compliance), and resistance to humidity and corrosion.

17.Q: How to mitigate inductance parameter drift in high-humidity environments?

A: Core mitigation strategies involve humidity-resistant component selection and protective manufacturing processes:

① Prefer humidity-resistant models: e.g., CSCF series ferrite inductors — MnZn ferrite cores resist oxidation/rusting under high humidity, fundamentally reducing moisture-induced drift in L and Q values.

② Implement board-level protection: Apply coating post-PCB assembly to form an effective moisture barrier — a proven and widely adopted secondary measure.

③ Verify critical certifications: Confirm that inductors pass 85°C/85% high-humidity testing or possess relevant MSL (Moisture Sensitivity Level) ratings — direct evidence of humidity resilience and parameter stability.

18.Q: Why do inductor for digital amplifier require low hysteresis loss?

A: Digital amplifiers operate in high-frequency switching mode, causing repeated core magnetization/demagnetization cycles. Low hysteresis loss reduces core heating, improves amplifier efficiency, and minimizes audio signal distortion — essential for high-fidelity sound reproduction.

19.Q: How do inductor for digital amplifier affect audio quality?

A: Inductance value stability directly governs audio signal fidelity. CODACA 's inductor for digital amplifier employ precision winding techniques achieving ±15% inductance tolerance, coupled with high-saturation, low-loss high-frequency core materials — ensuring excellent linearity, minimizing harmonic and intermodulation distortion, and delivering superior performance in premium home theater and automotive audio systems.

20.Q: Is there a direct correlation between SMD power inductor package size and rated power?

A: No inherent correlation exists. Selection should instead prioritize inductance value, frequency characteristics, and rated current — not physical footprint.

21.Q: What circuit symptoms occur when a high-current inductor saturates?

A: Upon saturation, inductance collapses sharply, impairing energy storage capability — resulting in abrupt current spikes, increased ripple, potential MOSFET over-current, drastic efficiency drop, and, in severe cases, catastrophic component failure. Adequate current margin must be designed in to prevent saturation.

22.Q: Why are ferrite cores predominantly used in inductor for digital amplifier?

A: Ferrite cores offer high permeability and low loss, excelling across 10 kHz – 3 MHz; their high resistivity suppresses eddy-current losses — making them ideal for digital amplifier high-frequency switching while balancing performance and cost.

23.Q: What PCB layout considerations apply to SMD power inductors?

A: Place away from high-speed signal traces to avoid coupling; ensure bottom pads are well grounded for thermal dissipation; maintain adequate clearance around the inductor to prevent thermal stacking; route high-current paths as short and wide as possible to minimize parasitic inductance.

24.Q: What is the purpose of magnetic shielding in high current power inductors?

A: Magnetic shielding prevents stray magnetic fields from interfering with nearby sensitive components (e.g., sensors, ADCs) and mitigates external field influence on inductor performance. Shielding — typically via core material encapsulation or copper shielding cans — forms a closed magnetic path, substantially reducing leakage flux.

25.Q: What are the primary failure modes of SMD power inductors?

A: Common failures include: winding burnout due to over-current; core aging induced by excessive temperature; solder joint detachment caused by mechanical vibration; and pin corrosion in humid environments. Reliability evaluation must account for application-specific current, thermal, and vibration stress profiles.

26.Q: In which types of power circuits are molded inductors best suited?

A: Molded inductors excel in DC/DC buck converters, point-of-load (POL) supplies, and server power systems — especially where high current density and miniaturization are critical.