An automotive power-inductor specification is useful only when the full part number, test conditions and limits are clear. A series-wide range cannot show whether one candidate will retain enough inductance, carry the circuit current or stay within its temperature limit. Sunlord's AS1A provides a practical example of how to read those distinctions without turning a product announcement into a design guarantee.
Use the current catalogue and the complete part number
This guide uses Sunlord's AS1A catalogue, revised 2026/09/21, an 18-page document linked from the manufacturer's product catalogue. Page 1 explains the ordering code, page 10 contains AS1A6020 entries, and page 12 defines current ratings. Keep the tolerance, packaging and any design suffix with the part number.
The AS1A release dated 2025-02-26 is useful background, but broad claims about efficiency, strength or production do not replace the controlled component specification. This guide does not repeat comparative performance numbers without the relevant samples and test conditions.
Read one exact row instead of combining series ranges
The following example is AS1A60201R0MT. The current entries quoted below are specifically typical values, not guaranteed allowable operating currents.
| Parameter | Catalogue entry | Condition or limitation |
|---|---|---|
| Inductance L | 1.0 µH, ±20% | 1 MHz / 1 V; page 10 |
| DCR | 0.025 Ω Max.; 0.019 Ω Typ. | Do not interchange the columns; the row does not separately state a DCR test temperature |
| Saturation current Isat | 7.40 A Typ. | About 30% inductance reduction; page 12 note |
| Heat-rating current Irms | 4.20 A Typ. | DC producing about 40°C rise from 20°C ambient; page 12 note |
| Operating temperature | −55°C to +150°C | Includes self-heating; page 1 |
The source also has current columns labeled “Max.” and “Typ.” and a separate rated-current definition. Do not silently rename them or choose the larger typical number as a guaranteed limit. Obtain the manufacturer's approved limits and temperature-dependent data for the intended full part number.
Separate magnetic, thermal and qualification evidence
Isat describes an inductance-drop criterion; Irms describes heating under a test setup. The catalogue's rated-current note uses the smaller of its Isat(Max.) and Irms(Max.) entries. None of these names removes the need to check peak current, RMS current, required inductance and transients separately. Coilcraft's current and temperature note provides a useful explanation of the distinction; its own test conditions must not be substituted for Sunlord's.
The +150°C ceiling includes self-heating. It is not permission to operate at +150°C ambient while adding winding and core losses. The announcement and the later catalogue differ at the lower temperature endpoint; use the identified catalogue version here and resolve procurement requirements with the manufacturer.
Page 1 labels AS1A “AEC-Q200-G0 verified.” This is a supplier statement, not a qualification review performed for this article. Coilcraft's AEC-Q200 guide describes component stress qualification. Request the applicable report and customer acceptance requirements; a label alone does not approve a vehicle module or a safety function.
Calculate a waveform example with explicit assumptions
This separate calculation is not measured AS1A performance. Assume continuous current with triangular ripple: 3 A DC, 1 A peak-to-peak ripple and 0.040 Ω DCR at the evaluated condition. That resistance is an example input, not the catalogue value in the table.
I_peak = I_DC + ΔI_pp / 2 = 3.50 A
I_RMS = √(I_DC² + ΔI_pp² / 12) ≈ 3.014 A
P_R = (3² + 1² / 12) × 0.040 ≈ 0.3633 WUse peak current to locate the relevant biased-inductance data, and RMS current to assess winding heating. The calculation excludes additional AC winding and core losses. Without the board's thermal behavior it cannot predict temperature rise, efficiency or life. Startup, overload and fault waveforms need their own checks.
Build a specification that can be reviewed and purchased
- Record the complete order code, catalogue and approved drawing revision, supplier and change-notification arrangements.
- Specify inductance and tolerance at the measurement frequency, then verify usable inductance at the actual DC bias and temperature.
- Separate typical values from guaranteed limits. Retain saturation criteria, heating-test conditions, DCR conditions and temperature curves.
- Check actual board losses and temperatures with the intended converter, layout and cooling; archive waveforms and measurement conditions.
- Obtain qualification evidence for the applicable part and changes. Leave vehicle safety, customer qualification and final module acceptance to the responsible engineers.
Use the inductor current check for preliminary calculations and the datasheet directory to locate candidate documents. They do not replace an approved component specification or board validation.
References and revision
The current Sunlord catalogue supplies the exact row and definitions; the release provides historical context. Coilcraft's two linked guides explain rating and qualification concepts, not Sunlord-specific test results. No efficiency, mechanical-test or customer-qualification result is claimed for this article.
Revised 2026-10-26: repaired the source trail, replaced series ranges with a complete-model example, separated typical current values from limits and clarified temperature including self-heating. Added an explicitly hypothetical calculation. AI-assisted editorial review only; independent native-speaker engineering approval and application-specific automotive acceptance remain outstanding. Original URL and publication date are retained in the editorial record.
