For a power-conversion board in an Irish data-centre project, the Walsin Technology (Walsin) WLPH inductor range is thinner on data than it looks. Of 41 WLPH rows in the export, 5 print a self-resonant frequency, 0 print a saturation current, and neither of the 2 WLPH lines on our 23 September 2026 shelf is one of the 5.
Venatech Limited, an authorised Walsin distributor in Hong Kong, wrote this for an engineer or buyer in Ireland who is specifying converters, storage or backup power around a data-centre site. It is built from the 5,411-row Walsin inductor export Walsin_Inductor_ALL.xlsx and our stock list of 1,125 part numbers as at 23 September 2026. Every part number is real, and every rule statement names its source, its date and the day we fetched it.
What did Ireland’s regulator decide for data-centre power?
It decided that new data centres must bring their own generation or storage. The Commission for Regulation of Utilities (CRU) published its Large Energy Users connection decision on 12 December 2025: new data centres must add generation or storage sized to the grid import capacity they request, and meet at least 80% of annual demand from new renewables in the Republic of Ireland. We read two sources in full and tabulate the points a component buyer can use.
| Point | What the source says | Source and date | What it means for a component buyer | Match / mismatch |
|---|---|---|---|---|
| Own generation or storage | Capacity on site or nearby, sized to the requested maximum import, trading in the wholesale market | CRU news item, 12 December 2025 | More power conversion near the site | Match with a power-stage question; the source names no component |
| Size bands | Under 1 MVA largely exempt; 1 MVA to under 10 MVA an auto-producer unit for 100% of import on a de-rated basis; 10 MVA and above dispatchable generation or storage for 100% of import | A&L Goodbody, 15 April 2026 | Different projects, different power stages | Match for scope; thresholds are the law firm’s summary |
| Renewable supply | At least 80% of annual demand from renewables generated in Ireland, within six years of energisation | CRU, 12 December 2025; A&L Goodbody, 15 April 2026 | A grid-side matter, not a part-level rule | Mismatch with a component claim: none is made |
| Location | EirGrid and ESB Networks assess each application and connection may be refused in a constrained area | A&L Goodbody, 15 April 2026 | Project timing risk, not a part rule | Mismatch: no component paperwork is named |
The firm also reported that the system operators were to publish a connection process by 31 March 2026 and had not done so by its article date. We have not checked whether they have since. We give no view on any site’s chances of connection.
What does that change for a power-conversion bill of materials?
More of the plant is power electronics, and each converter needs an inductor chosen on figures that must be printed. That is our view, not the regulator’s: a site that must carry its own storage or generation adds converters, and each converter’s inductor is chosen on rated current, saturation current and self-resonant frequency. Whether an Irish project uses a Walsin part is for its engineers to decide.
We are not saying Irish data centres use Walsin inductors, and we name no customer or site. We are saying the three figures decide whether a part passes qualification. A rated current without a saturation current leaves the engineer to measure it. Our posts on rated current against saturation current and on inductor self-resonant frequency explain why.
We hold no Walsin datasheet for any of the 5,411 inductor rows. Walsin’s own site, passivecomponent.com, is where its specifications live, and every specification statement below comes from the export, not from a datasheet.
How much of the Walsin WLPH range prints the figures a power stage needs?
Very little of it. The export lists 41 WLPH rows in two series, 22 plain WLPH and 19 WLPH(HC). None of the 41 prints a saturation current. Only 5, all HC rows in the 2520 body at 1.2 mm, print a self-resonant frequency and a Q. The other 36 show 0 in both columns, which is an empty field, not a measurement.
We counted the columns row by row. The 22 plain rows print rated current and DC resistance and nothing else a designer would use to size a ripple budget. Both lines on our shelf are plain rows. The table sets each stocked line beside its HC twin at the same body size and inductance.
| Walsin part | Series | Size and thickness | Inductance | DCR | Rated current | SRF(min) and Q min | On our shelf, 23 Sep 2026 | Match / mismatch against stocked WLPH252012M2R2PP |
|---|---|---|---|---|---|---|---|---|
WLPH252012M2R2PP |
WLPH | 2520, 1.2 mm | 2.2 µH | 85 mΩ | 2.27 A | 0 and 0 | Yes | Reference |
WLPH252012M2R2PS |
WLPH(HC) | 2520, 1.2 mm | 2.2 µH | 74 mΩ | 2.5 A | 50 and 30 | No | Mismatch: lower DCR, higher current, and it prints SRF and Q |
WLPH252010M2R2PP |
WLPH | 2520, 1.0 mm | 2.2 µH | 99 mΩ | 2.3 A | 0 and 0 | No | Mismatch: 0.2 mm thinner, 14 mΩ more DCR |
WLPH252012M4R7PP |
WLPH | 2520, 1.2 mm | 4.7 µH | 196 mΩ | 1.61 A | 0 and 0 | Yes | Second stocked line |
WLPH252012M4R7PS |
WLPH(HC) | 2520, 1.2 mm | 4.7 µH | 150 mΩ | 1.8 A | 35 and 30 | No | Mismatch with the stocked 4.7 µH line: lower DCR, prints SRF |
The suffix pair PP and PS is the only visible difference in the part number, and it separates a part that prints SRF and Q from one that does not. Walsin’s export does not explain what the letters mean, so we do not either. We have not seen this 5-of-41 count published elsewhere. A filter on inductance, size and thickness returns both rows of each pair, and only the series column separates them. Confirm against Walsin’s datasheet and qualify in your own circuit.
What does the Hong Kong shelf hold for a power stage?
Two inductors out of 1,125 lines. Our stock list as at 23 September 2026 holds 2 inductor lines, WLPH252012M2R2PP and WLPH252012M4R7PP, so inductors are 0.2% of the lines on the shelf. Both are in the plain series, and both lack a printed saturation current.
| Need on a power-conversion board | What we counted, 23 Sep 2026 | Example | Match / mismatch |
|---|---|---|---|
| Inductor with printed saturation current | 0 of 2 inductor lines; 0 of 41 WLPH rows | none | Mismatch: ask Walsin for the figure in writing |
| Inductor with printed SRF | 0 of 2 inductor lines; 5 of 41 WLPH rows | WLPH252012M2R2PS (not stocked) |
Mismatch for the shelf, match for the catalogue |
| Higher-current choice | 2 stocked lines at 2.27 A and 1.61 A | WLPH252012M2R2PP |
Match for low-ampere rails only |
| Bulk capacitance beside it | 51 stocked X5R MLCC lines | 0805X106K500CT |
Match for local decoupling; check voltage |
The stock list is a dated snapshot and moves. Our ready stock page shows what is held in Hong Kong now, and anything else is a factory order. The inductor range lists the families, and our post on multilayer against wirewound chip inductors frames the choice.
What will we not claim about Ireland?
Anything about the site, the grid or the customs side. We hold no Irish entity, office or stock, and we state no duty rate, tariff code, transit time, freight cost or carrier. Our locations are Hong Kong, Shenzhen, Singapore and Jiangmen, with Chengdu in preparation.
Your compliance team and broker own the import side. We supply parts with lot and date-code traceability, a certificate of conformity per shipment on request and original sealed Walsin packaging. We do not hold a Walsin REACH, SVHC, PFAS, ISO 9001, IATF 16949, PPAP or IMDS document, and none appears in the 451 pages of the 28 datasheets we hold.
What we can do is the cross-reference. Paste your incumbent inductor into the free cross-reference tool, which decodes 18 manufacturers’ part numbers across 800,000+ crossable parts, or load a BOM. Read the differences field by field. Our address is Unit 207, 2/F, Sun Ling Plaza, 30 On Kui Street, Fanling, N.T., Hong Kong, telephone (852) 2628 4777.
The short version
The Irish regulator’s December 2025 decision pushes new data centres to carry their own generation or storage, and that is our reason to look at power-stage inductors. The Walsin WLPH range prints a self-resonant frequency on 5 of 41 rows and a saturation current on none. Neither of the 2 stocked inductor lines, as at 23 September 2026, is among the 5.
Send us the inductor from one converter on your bill of materials and we will return the Walsin parts, with every blank figure marked as blank. Which inductor figure would you refuse to design around without?
Sources
Fetched 20 October 2026. The rule statements above come from these pages; every part statement comes from our own Walsin inductor export and stock list.
- Commission for Regulation of Utilities, “The CRU Publishes its Decision on New Electricity Connection Policy for Data Centres”, 12 December 2025: https://www.cru.ie/about-us/news/the-cru-publishes-its-decision-on-new-electricity-connection-policy-for-data-centres/
- A&L Goodbody, “Data centres and the grid: how recent Irish policy will shape the sector”, 15 April 2026: https://www.algoodbody.com/insights-publications/data-centres-and-the-grid-how-recent-irish-policy-will-shape-the-sectordata-centres-and-the-grid-how-recent-irish-policy-will-shape-the-sector
Frequently asked questions
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What did Ireland’s regulator decide for data-centre power?
On 12 December 2025 the CRU published its connection decision. New data centres must add generation or storage sized to the grid import they request, and meet at least 80% of annual demand from new Irish renewables. A&L Goodbody summarised the size bands on 15 April 2026.
Does the decision say anything about inductors or other components?
No. Neither source we read names a component. Our link to power-stage inductors is our own view: a site carrying its own storage or generation adds converters, and each converter’s inductor is chosen on printed figures. Confirm project needs with your engineers and compliance team.
How many Walsin WLPH inductor rows print a saturation current?
None. The export holds 41 WLPH rows in two series and all 41 leave saturation current blank. Only 5 rows, all WLPH(HC) in the 2520 body at 1.2 mm, print a self-resonant frequency and a Q. The other 36 show 0 in both columns.
Which Walsin inductors do you hold in Hong Kong stock?
Two, as at 23 September 2026: WLPH252012M2R2PP and WLPH252012M4R7PP. Both are plain WLPH rows, so neither prints a self-resonant frequency or saturation current in the export. Stock moves, so ask for the current position before you plan around it.
Can the HC twin replace a plain WLPH part?
We state differences, not equivalence. WLPH252012M2R2PS matches WLPH252012M2R2PP on size, thickness and inductance, has a lower DCR and higher rated current, and prints SRF and Q. Confirm against Walsin’s datasheet and qualify in your own circuit.
Do you hold Irish stock or give import advice?
No. We hold no Irish entity or stock and state no duty, tariff code or transit time. Confirm import questions with your compliance team and broker. We supply parts with lot and date-code traceability and a certificate of conformity on request.