An anti surge chip resistor is a construction, not a published number. We opened all 14 of Walsin’s anti-surge export files — 17,180 part numbers — and counted 10 columns per row. Zero of the five fields a pulse decision needs are among them: pulse voltage, duration, waveform, single-pulse energy, repetitive rating.
Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the full set of Walsin Technology (Walsin) chip resistor parametric export files. This post is measured from the 14 files matching Thick_Film_Anti_Surge_Chip_Resistor_*.xlsx in Walsin_ChipR_Product_Data, cross-checked against the two chip resistor datasheets we hold. Every part number below is real and came out of one of those files.
What does Walsin’s anti surge chip resistor export actually contain?
Ten columns, and the same ten on every anti-surge row as on the general-purpose shelf next to it. We opened Thick_Film_Anti_Surge_Chip_Resistor_1.xlsx and its 13 siblings and listed the header row on each: Part Number, Series Group, Series, Size, Resistance, Tolerance, TCR, Rated Power, Packaging, Termination. That is the whole file. Nothing marks a row as surge-rated except the text inside the Series cell.
| Field | Present in the anti-surge export? | Transfers to a surge decision? |
|---|---|---|
| Part Number, Size, Resistance, Tolerance, TCR, Rated Power, Packaging, Termination | Yes, on all 17,180 rows | Partly — construction, not pulse data |
| Series / Series Group text | Yes | The word “Surge” is the only surge-specific content in the file |
| Pulse voltage | No column exists | No |
| Pulse duration / waveform (for example 8/20 µs) | No column exists | No |
| Single-pulse energy | No column exists | No |
| Repetitive pulse rating | No column exists | No |
We have not seen this counted anywhere: of the five fields a real pulse-withstanding decision needs, the export publishes zero, on all 17,180 rows across all three series.
Which fields does a pulse-withstanding decision actually need?
Five, and none of them is rated power. Continuous power rating describes a resistor heating evenly over seconds. A surge event delivers its energy in microseconds, through whatever current-density hot spot the element geometry creates, and the two failure modes are governed by different numbers. An engineer qualifying a surge path needs the pulse voltage the part must survive, the pulse duration and waveform (IEC 61000-4-5 testing commonly uses an 8/20 µs current waveform; telecom work often uses 10/1000 µs), the single-pulse energy rating in joules, and how many repeat events the part tolerates before it drifts or opens. Rated power, tolerance and TCR answer a different question and answer it well — just not this one.
Is the export file suffix a wattage code or a tolerance code?
It is a tolerance code, not a wattage code, and we checked it two ways. The 14 files are named by a suffix — 0_05, 0_1, 0_10, 0_20, 0_25, 0_30, 0_5, 1, 2, 5, 10, 20, 50, Jumper — and it would be easy to read that as a power-rating ladder, because the general-purpose shelf next door genuinely does split by wattage (Thick_Film_General_Purpose_1_1W.xlsx, ..._1_1_4W.xlsx, and so on). The anti-surge shelf does not. We opened every one of the 14 files: 5 return rows — 0_5 (1,370 rows), 1 (6,165), 5 (4,085), 10 (2,780) and 20 (2,780), totalling the full 17,180 — and every row in each is tagged ±0.5%, ±1%, ±5%, ±10% or ±20% respectively. The other 9 files (0_05, 0_1, 0_10, 0_20, 0_25, 0_30, 2, 50, Jumper) return zero rows. Then we checked the part numbers themselves: Walsin’s own EIA tolerance letter is baked into every code — D for ±0.5%, F for ±1%, J for ±5%, K for ±10%, M for ±20% — and we verified all 17,180 part numbers against that letter and found zero mismatches with the filename-derived tolerance. The suffix is tolerance, confirmed twice, not wattage.
Do either of our two resistor datasheets cover anti-surge at all?
No, and we say so rather than imply coverage we do not have. Venatech holds exactly two chip resistor datasheets out of the 28 Walsin PDFs we hold in total: Walsin_MR_Automotive_Thick_Film_Chip_Resistor.pdf and Walsin_WR_General_Purpose_Chip_Resistor.pdf (the latter dated ASC_WR_V24, September 2016 — ten years old, and we disclose that on every post that cites it). Neither sheet names any of the three anti-surge series — Thick Film Anti-Surge Chip Resistor, Thick Film Triple Power Surge Chip Resistor (Automotive), or Thick Flim Power Surge Chip Resistor (Automotive), the last spelled that way in Walsin’s own export. Both sheets we hold carry one overload-related test condition, Short Time Overload: 2.5 times the rated continuous working voltage applied for 5 seconds, checking resistance drift afterward. That is a thermal overload test at DC or RMS, run once, for 5 seconds. It is not a pulse withstand curve and it is not stated for the surge series at all.
Why do 9 of the 14 anti-surge export files return nothing?
Because the shelf is narrower than the file list implies. We grouped all 17,180 rows by series and found the gap is structural, not random. The baseline series, Thick Film Anti-Surge Chip Resistor, stocks only ±5%, ±10% and ±20% across six case sizes. Thick Film Triple Power Surge Chip Resistor (Automotive) stocks only ±1% and ±5%, but reaches all seven case sizes at exactly 830 parts each. Thick Flim Power Surge Chip Resistor (Automotive) reaches ±0.5% and ±1%, but only at 0603 and 0805.
| Series | Rows | Tolerances with any data | Case sizes covered | Match / mismatch vs “every tolerance, every size in one series” |
|---|---|---|---|---|
| Thick Film Anti-Surge Chip Resistor | 8,340 | ±5%, ±10%, ±20% | 6 (0603–2512, no 0402) | Mismatch — misses 0402 and both automotive tolerances |
| Thick Film Triple Power Surge Chip Resistor (Automotive) | 5,810 | ±1%, ±5% | 7 (0402–2512, 830 each) | Match on every case size; mismatch — no ±10%, ±20% |
| Thick Flim Power Surge Chip Resistor (Automotive) | 3,030 | ±0.5%, ±1%, ±5% | 2 (0603, 0805 only) | Match on the tightest tolerance; mismatch — misses 5 of 7 case sizes |
No series in the family stocks tighter than ±0.5%, and no series stocks a 0 Ω jumper — the Thick_Film_Anti_Surge_Chip_Resistor_Jumper.xlsx file is one of the 9 that returns zero rows.
What should a buyer do without a published pulse figure?
Ask for the series datasheet before you design a part into a surge path, because the parametric export was never going to answer that question. MK06S1R00FTL (Thick Flim Power Surge, Automotive, 0603, 1.00 Ω, ±1%, 1/4 W) and MF08E1000FTL (Thick Film Triple Power Surge, Automotive, 0805, 100 Ω, ±1%, 1/2 W) are both real, both in our extract, and both carry the same ten columns as every general-purpose part next to them — no pulse rating on either. The trade press has reported MLCC and passive component lead times stretching through 2026 as AI server and EV volumes draw on the same manufacturing capacity, which is exactly the environment in which a buyer reaches for a second source without the datasheet in hand. Do not let that pressure substitute a blank cell for a real pulse figure.
- State the pulse, not just the wattage, in your enquiry. Tell us the waveform, peak voltage and required single-pulse energy and we will ask Walsin for the series sheet rather than paraphrase a number we cannot see.
- Cross the rest of the BOM in the same pass. The free cross-reference tool takes up to 500 pasted part numbers or an Excel or CSV file, decodes 18 manufacturers’ part numbers and matches against 800,000+ crossable Walsin part numbers, stating every difference field by field.
- Check what is physically in Hong Kong on ready stock, a dated snapshot as at 23 September 2026, before you commit a surge-critical part to a production slot.
We will not call a crossed part equivalent. We will show you exactly which of the ten columns matched and which five fields were never there to match in the first place.
For the construction argument and real surge part numbers compared field by field, see Anti-surge chip resistors. For how rated power actually steps by case size across the whole resistor catalogue, see Chip resistor power rating by case size. The full line is on the Walsin chip resistor range page.
The short version
Walsin’s anti-surge chip resistor export holds 17,180 part numbers across three series and exactly 10 columns. Zero of those columns are pulse voltage, pulse duration, waveform, single-pulse energy or repetitive pulse rating — the five fields a surge decision actually needs. The 14-file naming convention looks like a wattage ladder and is a tolerance ladder instead, verified against the EIA letter in all 17,180 part numbers with zero mismatches. We hold two chip resistor datasheets and neither names an anti-surge series by name.
Send us the pulse waveform, voltage and energy your circuit will see, plus the case size and resistance you can afford, and we will ask Walsin for the series sheet rather than hand you back a column we know is empty — then tell you honestly if the figure still is not published after we ask.
Frequently asked questions
Does Walsin’s parametric export publish a surge or pulse voltage for anti-surge chip resistors?
No. We opened all 14 export files covering the family — 17,180 part numbers across three series — and counted the columns on every row: Part Number, Series Group, Series, Size, Resistance, Tolerance, TCR, Rated Power, Packaging, Termination. None of them is a pulse voltage, pulse duration, waveform, single-pulse energy or repetitive pulse rating field.
Is the number after “Anti_Surge_Chip_Resistor” in Walsin’s filenames a wattage or a tolerance?
A tolerance. We checked every one of the 14 files and confirmed it against the EIA tolerance letter embedded in each of the 17,180 part numbers — D for 0.5 percent, F for 1 percent, J for 5 percent, K for 10 percent and M for 20 percent — with zero mismatches. The general-purpose shelf next to it does split by wattage in its own filenames; the anti-surge shelf does not.
Do either of Venatech’s two resistor datasheets cover anti-surge chip resistors?
No. We hold the MR automotive general-purpose sheet and the WR general-purpose sheet, and neither names any of the three anti-surge series. Both state only a Short Time Overload test — 2.5 times rated working voltage for 5 seconds — which is a thermal DC or RMS overload check, not a pulse withstand curve.
Why do 9 of the 14 anti-surge export files return zero rows?
Because no series in the family stocks every tolerance. The baseline Thick Film Anti-Surge Chip Resistor series covers plus or minus 5, 10 and 20 percent only; the two automotive power-surge series cover plus or minus 0.5 and 1 percent instead. Nothing in the family reaches tighter than plus or minus 0.5 percent or a 0 ohm jumper, so those files are empty.
How many anti-surge chip resistor part numbers does Walsin’s export actually hold?
17,180, split across three series: 8,340 in Thick Film Anti-Surge Chip Resistor, 5,810 in Thick Film Triple Power Surge Chip Resistor (Automotive) and 3,030 in Thick Flim Power Surge Chip Resistor (Automotive), the last spelled that way in Walsin’s own file.
What should I do if my design needs a published single-pulse energy rating?
Ask us for the series datasheet before you design the part in, because the number is not in the parametric export we hold. Tell us the waveform, peak voltage and resistance and case size you need, and we will put the request to Walsin rather than estimate a figure from the continuous power rating.