Inductor Inductance Values by Case Size: Only 13 of 49 E12 Steps Exist in All Six Walsin Sizes, Counted for Germany

Inductor inductance values by case size are not one ladder. We parsed all 4,769 inductance rows in Walsin’s export: of 49 E12 steps from 1 nH to 10 µH, only 13 exist in all six main case sizes, all between 10 nH and 100 nH. Fix the value before the footprint, and a size may hold no part.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the inductor parametric export of Walsin Technology (Walsin), 5,410 real rows, and no inductor datasheet. This post is written from Walsin_Inductor_ALL.xlsx, with the QA test row Test123999 excluded. Our earlier post counted the whole inductance ladder, 171 rungs. This one cuts it by case size, which is the cut a layout actually forces. Every part number below is real.

How many distinct inductance values does each Walsin case size publish?

Between 35 and 84 in the six main sizes, and the spread does not follow size. We converted every value to nanohenries first, because the export writes some in nH and some in µH, then counted per Size string. 641 of the 5,410 rows are ferrite beads with an ohm symbol in Unit and no inductance, which leaves 4,769. The six main sizes hold 4,315 of those rows, and 454 sit in 29 smaller size strings. A step counts as filled if any row lies within 2 percent of the E12 nominal.

Size	Rows	Distinct values	Published range	E12 steps in range, to 10 µH	Filled	Values off E12	Match / mismatch against a complete E12 ladder in its own range
1005(0402)	1,001	70	0.3 nH to 150 nH	27	27	42	Match — no gap
0603(0201)	888	73	0.3 nH to 100 nH	25	25	48	Match — no gap
1608(0603)	785	84	1 nH to 10 µH	49	43	41	Mismatch — 6 steps absent
2012(0805)	706	80	2.2 nH to 27 µH	45	43	32	Mismatch — 2 steps absent
2520(1008)	659	56	3 nH to 22 µH	43	38	15	Mismatch — 5 steps absent
3225(1210)	276	35	4.7 nH to 3.3 µH	35	32	3	Mismatch — 3 steps absent

The two smallest sizes are dense: 0603(0201) has 73 distinct values in a range that spans two decades. The largest of the six, 3225(1210), has 35 and only 3 values off E12, so it is nearly a pure E12 line.

Which E12 inductance steps exist in all six main case sizes?

Thirteen, and they are exactly 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 and 100 nH. We counted 49 E12 steps from 1 nH to 10 µH against the six sizes: 13 steps are offered in all six, 4 in five, 19 in four, 8 in three and 5 in only two. No step is offered in just one size or in none. The ladder has no hole, but it is not one shared ladder either.

Step	1005	0603	1608	2012	2520	3225	Sizes offering it	Match / mismatch against “I can pick my size afterwards”
4.7 nH	21	17	15	0	0	6	4 of 6	Mismatch — nothing at 2012 or 2520
10 nH	21	14	15	12	9	8	6 of 6	Match — every size
100 nH	12	1	15	13	18	8	6 of 6	Match, but 0603 holds one part
1 µH	0	0	3	16	20	8	4 of 6	Mismatch — nothing at 1005 or 0603
4.7 µH	0	0	2	9	17	0	3 of 6	Mismatch — nothing at 3225
10 µH	0	0	1	5	9	0	3 of 6	Mismatch — one 1608 part

Cells are part numbers. We have not seen this counted anywhere. Real parts at 10 nH, one per size: WLCW1005Z0G10NTB, WLCM0603Z0H10NTB, WLCW1608Z0G10NPB, WLCW2012Z0G10NPB, WLCW2520Z0J10NPB and WLCW3225Z0K10NPB. Case-size codes themselves are covered in passive component case sizes, imperial and metric.

Which E12 steps will a designer find missing, and where?

Sixteen cells, across four sizes. We checked each size against the E12 steps inside its own published range, so a missing step is a hole in a ladder the family otherwise covers. 1608(0603) lacks six steps, 2520(1008) five, 3225(1210) three and 2012(0805) two. 1005(0402) and 0603(0201) lack none. Off-E12 values sometimes sit next to a hole, so check the whole list.

Size	E12 steps absent	Nearest published values either side	Real part at a neighbour	Your incumbent part	Match / mismatch
2012(0805)	3.9 nH, 4.7 nH	3.3 nH and 5.6 nH	WLCW2012Z0J3N3PB, WLCW2012Z0J5N6PB	___	Mismatch — a 4.7 nH match has no 0805 part
2520(1008)	3.3, 3.9, 4.7, 5.6, 6.8 nH	3.0, 4.1, 7.8 and 8.2 nH	WLCW2520Z0J8N2PB	___	Mismatch — the list jumps from 4.1 nH to 7.8 nH
3225(1210)	6.8 nH, 8.2 nH, 2.7 µH	5.6 and 10 nH; 2.2 and 3.3 µH	WLCW3225Z0K10NPB, WLCW3225Z0K3R3PB	___	Mismatch — 3.3 µH exists, 2.7 µH does not
1608(0603)	1.2, 2.7, 3.9, 5.6, 6.8, 8.2 µH	1.0, 1.5, 1.8, 2.2, 3.3, 4.7 and 10 µH	WLFI1608Z0M1R0TB, WLFI1608Z0M2R2TB, WLFI1608Z0M4R7TB, WLFI1608Z0M100TB	___	Mismatch — 14 parts above 1 µH, 7 values

The 1608 line shows the pattern best. Above 1 µH it holds 14 parts on 7 distinct values, from WLFI1608Z0M1R0TB to WLFI1608Z0M100TB. The inductor you would round up to 6.8 µH is not there.

Which inductance values exist in only one case size?

Forty, among the six main sizes, plus 29 more that appear in none of them. We counted every distinct value in each size and then how many of the six sizes carried it. The six main sizes together hold 142 distinct values; 40 of those are in exactly one size, and the other 29 of the 171 sit only in the smaller size strings. A value found once is not a ladder step, it is a single source.

The one-size values include 0.9, 1.4, 1.7, 2.3, 2.6 and 3.1 nH, 14, 19 and 37 nH, and 130, 160, 210 and 260 nH. At the top of the range 18,000 and 27,000 nH are also single-size values. If your calculation lands on one of them, the choice of size has already been made by the catalogue. This is the same one-value risk that our post on RF matching inductors describes from the application side.

Does one case size appear under two different size strings?

Yes, five times. We read the Size column as raw strings: the export has 40 distinct strings across 5,410 rows. Five case codes are written two ways, with and without the imperial code in brackets, and 141 rows carry the bare form. A filter on 2520(1008) misses the bare 2520 rows, which are the WLPH, WLPH(HC), WIP and WIP_S power series.

Code	Bare string, rows	Bracketed string, rows	Real part, bare string	Real part, bracketed string	Match / mismatch
2520	52	664	WLPH252010MR47PP	WLCW2520Z0GR47PB	Mismatch — same 470 nH, same code, different strings
2016	32	20	WLPH201610MR68PP	none at 680 nH	Mismatch — bracketed string holds 7 of the 10 values
3225	8	291	WIP322512A-3R3ML	WLCW3225Z0K3R3PB	Mismatch — bare string adds 4 values the bracketed lacks
2012	47	883	none with inductance	WLCW2012Z0G10NPB	Mismatch — 45 of the 47 bare rows are beads
3216	2	72	none with inductance	none with inductance	Match on values, mismatch on strings

For 2016, a filter on the bracketed string returns 7 of the 10 values in that code. It loses 680 nH, 1.5 µH and 4 µH. Those three exist only under the bare string, for example WLPH201610M1R5PP. We have not counted whether the bare and bracketed forms describe different bodies. Walsin would need to confirm that.

What should a German designer check before fixing an inductance value?

Check the size first, then the value, and keep the incumbent column honest. The six main sizes offer 398 value-slots between them but only 142 distinct values, so the same nominal is repeatedly the only choice at a given size. Do not assume an E12 value exists in the footprint you have drawn.

1. Choose the footprint, then read the ladder for that footprint. At 0805 there is no 4.7 nH; at 0201 there is no value above 100 nH.
2. Normalise units and sizes before you filter. The export mixes nH and µH, and writes five case codes two ways.
3. Leave the incumbent part in its own column. Compare tolerance, thickness, DC resistance and self-resonant frequency field by field; value alone settles nothing.

We hold no inductor datasheet, so the export is the only source we can show you. Our free cross-reference tool states differences from your original instead of hiding them behind a tick. What is held in Hong Kong is on ready stock, 1,125 part numbers as at 23 September 2026, a dated snapshot and not a live feed. The inductor range is on the inductor page.

The short version

Walsin’s inductor line is not one ladder. We counted 4,769 inductance rows: 171 distinct values overall, between 35 and 84 per main case size, and only 13 of 49 E12 steps from 1 nH to 10 µH offered in all six main sizes. 16 steps are absent inside their own size’s range, 40 values exist in one main size only, and five case codes are written two ways across 141 rows. Everything here is export data with no datasheet behind it. We will not tell you a part matches on value alone. We will show you the size it exists in. Confirm against both datasheets and qualify in your own circuit.

Send us the inductance and footprint from your schematic and we will tell you which sizes hold it. And a question back: did your last inductor choice come from the value, or from the footprint that was already on the board?

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Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"How many inductance values does Walsin publish for chip inductors?","content":"171 distinct values across 4,769 rows, once nanohenry and microhenry entries are normalised, in the export we hold. Per main case size the count runs from 35 at 3225(1210) to 84 at 1608(0603). 641 further rows are ferrite beads with no inductance. We hold no datasheet, so confirm against Walsin's own site.","visible":true},{"id":"faq-question-02","title":"Which inductance steps are available in every main case size?","content":"Thirteen: 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 and 100 nH. We checked 49 E12 steps from 1 nH to 10 µH against 1005, 0603, 1608, 2012, 2520 and 3225. Only these thirteen have at least one part number in all six sizes.","visible":true},{"id":"faq-question-03","title":"Is there a 4.7 nH inductor in 0805 or 1008?","content":"Not in the export we parsed. The 2012(0805) line runs 2.2, 2.5, 2.7, 2.8, 2.9, 3.0 and 3.3 nH, then 5.6 nH. The 2520(1008) line jumps from 4.1 nH to 7.8 nH. A 4.7 nH part exists in 1005, 0603, 1608 and 3225, for example WLCW3225Z0K4N7PB.”,”visible”:true},{“id”:”faq-question-04″,”title”:”Does Walsin offer high inductance values in small case sizes?”,”content”:”No. 1005(0402) stops at 150 nH and 0603(0201) at 100 nH in the export. The 1608(0603) line reaches 10 µH on one part. Above 1 µH, 1608 holds 14 parts on 7 values, 2012 reaches 27 µH, and 2520 reaches 22 µH. Confirm each figure against Walsin’s own site.”,”visible”:true},{“id”:”faq-question-05″,”title”:”Why does a filter on 2520(1008) miss some Walsin inductors?”,”content”:”Five case codes are written two ways. 52 rows carry the bare string 2520 and 664 carry 2520(1008). The bare rows are the WLPH, WLPH(HC), WIP and WIP_S power series. Across all five codes, 141 rows use the bare form, so filter on the code, not the full string.”,”visible”:true},{“id”:”faq-question-06″,”title”:”Can I rely on the inductance column alone to cross an inductor?”,”content”:”No. Inductance is one field of several. Tolerance, thickness, DC resistance, self-resonant frequency and rated current must also agree, and most of those columns carry their own unit problems. We hold no inductor datasheet, so confirm against both datasheets and qualify the part in your own circuit.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

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