An automotive current sense resistor sits in every EV on-board charger, DC-DC converter and battery board, and Walsin Technology (Walsin) lists 5,799 of them in three automotive series; a 5 milliohm, 1 percent 2512 brief at 2 W or more returns 5 metal-plate parts. Venatech is Walsin’s authorised distributor in Hong Kong.
Venatech Limited, an authorised Walsin distributor in Hong Kong, wrote this for an engineer or buyer in or around Ulsan, South Korea, who is choosing the shunt for a charger, a DC-DC stage or a battery current monitor. We parsed Walsin’s chip resistor exports (137 .xlsx files, 234,815 rows) and our stock list as at 23 September 2026. Every part number is real. The hook is from November 2023 and we date it plainly.
What did just-auto report about Hyundai’s dedicated EV plant in Ulsan?
A plant sized for 200,000 EVs a year. just-auto reported on 13 November 2023 that Hyundai Motor broke ground on a dedicated EV plant in Ulsan with an investment of two trillion won, about 1.5 billion US dollars, an annual capacity of 200,000 battery electric vehicles, and mass production scheduled for the first quarter of 2026.
The report is three years old. We searched for a 2026 source on the plant’s start and could not fetch one we would cite, so we use the 2023 figures as the plan they were and do not claim a start date. The figures are the report’s, not ours, and we say nothing about what Hyundai or its suppliers buy. The point for a board engineer near Ulsan is the scale of the EV supply base around it: chargers, DC-DC converters and battery monitors, each measuring current through a low-ohm shunt.
How many Walsin automotive current sense resistors are there?
5,799. We counted the three Walsin current-sense series whose names carry Automotive: 3,809 in the Thick Film Power Low Ohm series, 1,572 in the Thick Film Low Ohm series and 418 in the Metal Plate series, for 5,799 distinct automotive part numbers.
| Walsin automotive series | Part numbers | Construction | Range in the export |
|---|---|---|---|
| Thick Film Power Low Ohm (Automotive) | 3,809 | Thick film | 50 to 976 milliohm, 0402 to 2512 |
| Thick Film Low Ohm (Automotive) | 1,572 | Thick film | 20 to 976 milliohm, 0603 to 2512 |
| Metal Plate Low Ohm, standard and Power (Automotive) | 418 | Metal plate | 0.5 to 100 milliohm, 1206 to 2512 |
The 418 metal-plate parts run from 0.5 milliohm to 100 milliohm in 1206, 2010 and 2512, rated 1/2 W to 3 W, with TCR from 50 to 100 ppm per degree in the export. Below about 10 milliohm, metal is the usual answer, because thick film cannot hold a low TCR at those values. Our guide to low-ohm current sense, thick film against metal explains why.
Which Walsin metal-plate shunts match a 5 milliohm, 1 percent, 2512 brief at 2 W or more?
Five do. We filtered the automotive metal-plate rows to 5 milliohm and found 28 part numbers; 8 are 2512 at 1 percent, and 5 of those are rated 2 W or 3 W, the band an on-board charger or DC-DC shunt usually needs.
| Walsin part | Series | Rated power | TCR (ppm/C) | Match / mismatch with a 5 milliohm, 1%, 2 W brief | Your incumbent |
|---|---|---|---|---|---|
WW25AR005FTLJ |
Metal Plate (Automotive) | 3 W | 70 | Match, power headroom | |
WW25BR005FTLJ |
Metal Plate (Automotive) | 3 W | 70 | Match, power headroom | |
WW25NR005FTLJ |
Metal Plate (Automotive) | 2 W | 50 | Match, lowest TCR | |
WW25RR005FTLJ |
Metal Plate Power (Automotive) | 2 W | 70 | Match | |
WW25KR005FTLJ |
Metal Plate Power (Automotive) | 2 W | 70 | Match | |
WW25MR005FTLJ |
Metal Plate (Automotive) | 1 W | 50 | Mismatch: 1 W | |
WW25QR005FTLJ |
Metal Plate Power (Automotive) | 1 W | 70 | Mismatch: 1 W | |
WW25JR005FTLJ |
Metal Plate Power (Automotive) | 1 W | 70 | Mismatch: 1 W |
At 5 milliohm and 20 A, a shunt dissipates 2 W, so the brief’s power line is not decoration. Check the derating curve and the pad layout on Walsin’s datasheet for the exact part, because a 2512 metal shunt’s real rating depends on copper area. Confirm against both datasheets and qualify in your own circuit.
What should an Ulsan EV engineer check beyond resistance and power?
Three things. Check the TCR against your accuracy budget, the Kelvin pad layout, and the AEC-Q200 paperwork; in our 5 milliohm 2512 brief the TCR ranges from 50 to 70 ppm per degree, which over a 100 degree rise moves the reading by 0.5 to 0.7 percent.
That drift can be larger than the 1 percent tolerance once the board heats, so a battery monitor that needs tight coulomb counting should start from the 50 ppm parts. Four-terminal (Kelvin) sensing removes the pad and trace resistance from the measurement; route the sense lines from the inner edge of each pad. Walsin’s datasheets say AEC-Q200 compliant, not certified, so request the qualification report for the exact part number. Our guide to Walsin automotive chip resistors and the AEC-Q200 split covers the paperwork, and the chip resistor range lists every family.
How does Venatech supply Walsin automotive shunts to Ulsan from Hong Kong?
Through our authorised Walsin channel. The 5,799 Walsin automotive current-sense parts, including the 5 shunts in the table, are quoted to order: request a quote and we source them through our authorised Walsin channel, in small lots for a pilot build or in production quantities.
We give no lead-time or stock promise. The ready-stock list is a Hong Kong snapshot as at 23 September 2026, never live-synced. We hold no ISO 9001 or IATF 16949 certificate of our own and give no customs or legal advice; confirm import and documentation questions with your compliance team.
How Venatech helps: how can an Ulsan EV team cross its shunt resistors?
In one upload. VenaMatch decodes 18 manufacturers’ part numbers and crosses 800,000+ parts to Walsin, marking each field as a match or a mismatch, so an Ulsan team can see which of its shunts and sense resistors cross to one of Walsin’s 5,799 automotive current-sense parts.
Use the cross-reference tool for a few parts, or upload the BOM for a whole charger or battery board. Venatech is Walsin’s authorised distributor in Hong Kong; Stackpole and Viking are lines we supply. Ask for a quote through the site and we reply from Hong Kong.
The short version
Hyundai planned a 200,000-a-year EV plant in Ulsan with production scheduled for early 2026, as just-auto reported in 2023. For the current sensing on EV chargers, DC-DC stages and battery boards, we counted 5,799 Walsin automotive current-sense resistors; a 5 milliohm, 1 percent 2512 brief at 2 W or more returns 5 metal-plate parts.
Send us your shunt lines with the current and accuracy you need, and we will return Walsin automotive crosses with every field difference marked. Does your shunt’s TCR drift exceed its tolerance once the board is hot?
Related reading
- Low-ohm current sense: thick film against metal
- Walsin automotive chip resistors and the AEC-Q200 split
- Passive components for an EV on-board charger
- VenaMatch cross-reference tool and ready-stock snapshot
Last reviewed 11 Nov 2026.
Sources
Fetched 11 November 2026.
- just-auto, Hyundai starts building new EV plant in South Korea, 13 November 2023 (older source, re-fetched 11 November 2026): https://www.just-auto.com/news/hyundai-starts-building-new-ev-plant-in-south-korea/
- Walsin chip resistor parametric exports (137 .xlsx files) and Venatech stock snapshot as at 23 September 2026, both re-measured by Venatech on 11 November 2026.
Frequently asked questions
How many automotive current sense resistors does Walsin offer for EV makers in Ulsan, South Korea?
We counted 5,799 distinct Walsin automotive current-sense part numbers: 3,809 Thick Film Power Low Ohm, 1,572 Thick Film Low Ohm and 418 Metal Plate. Venatech, Walsin’s authorised distributor in Hong Kong, quotes all of them.
Which Walsin shunt matches 5 milliohm, 1 percent, 2512, 2 W?
WW25NR005FTLJ, WW25RR005FTLJ and WW25KR005FTLJ at 2 watts, and WW25AR005FTLJ and WW25BR005FTLJ at 3 watts, all automotive metal plate. Check the derating curve and pad layout on the datasheet and qualify in your own circuit.
Why use a metal plate shunt instead of thick film at 5 milliohm?
At a few milliohm, thick film struggles to hold a low temperature coefficient, so the reading drifts as the board heats. Metal plate parts in Walsin’s automotive series list 50 to 100 ppm per degree across 0.5 to 100 milliohm.
Are Walsin automotive shunts AEC-Q200?
They sit in Walsin series named Automotive, and Walsin’s datasheets say AEC-Q200 compliant, not certified. Request the qualification report for the exact part number. Venatech makes no qualification claim of its own.
What did just-auto report about the Ulsan EV plant?
On 13 November 2023 it reported that Hyundai broke ground on a dedicated EV plant in Ulsan, investing two trillion won, about 1.5 billion US dollars, for 200,000 battery electric vehicles a year, with mass production scheduled for the first quarter of 2026.
Does Venatech hold Walsin automotive shunts in Hong Kong stock?
They are quoted to order: request a quote and we source them through our authorised Walsin channel. The ready-stock page is a snapshot dated 23 September 2026, and we give no stock or lead-time promise.