Chip Resistor Implied Working Voltage: 31,665 of 127,779 Walsin Rows Outside WR and MR Imply More Volts Than the Sheet Ceiling for Their Case Size

Chip resistor implied working voltage is the square root of rated power times resistance, and it is not a rating. Across 127,779 Walsin rows outside WR and MR, 31,665 (24.8 percent) imply more volts than the case-size ceiling Walsin prints for WR and MR. All 488 high ohm rows do.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the chip resistor parametric exports published by Walsin Technology (Walsin) and two chip resistor approval sheets. This post is written from both. Only the WR and MR series have a printed voltage ceiling; the other twelve series groups have no voltage column and no sheet. We parsed all 234,401 distinct part numbers, computed the root of power times resistance on every resistive row, and tested it against the ceiling the sheets print for each case size. Every part number below is real and every count is of part numbers, not pieces.

How many Walsin chip resistors outside WR and MR imply more volts than the sheet ceiling for their case size?

31,665 of 127,779, which is 24.8 percent. We removed 23 chip attenuators, whose resistance is in decibels, and 124 zero-ohm jumpers, leaving 234,254 resistive rows. Of those, 62,692 carry a WR or MR prefix and 171,562 do not. Of the 171,562, the 127,779 at 0402, 0603, 0805, 1206 and 1210 can be tested against the sheets’ own ceilings.

Case size	Ceiling printed for WR or MR (V)	Rows outside WR and MR	Rows whose root of P times R exceeds the ceiling	Share	Match / mismatch against the WR and MR rule
0402 (1005)	50	20,175	6,230	30.9%	Mismatch on 6,230 rows; the formula alone would promise more than 50 V
0603 (1608)	75	34,608	9,735	28.1%	Mismatch on 9,735 rows
0805 (2012)	150	30,286	6,504	21.5%	Mismatch on 6,504 rows
1206 (3216)	200	29,525	6,438	21.8%	Mismatch on 6,438 rows
1210 (3225)	200	13,185	2,758	20.9%	Mismatch on 2,758 rows; the 1210 ceiling is printed in the MR sheet only
Total		127,779	31,665	24.8%

The ceilings come from Walsin_WR_General_Purpose_Chip_Resistor.pdf (ASC_WR_V24, September 2016) and Walsin_MR_Automotive_Thick_Film_Chip_Resistor.pdf. Both sheets define the continuous working voltage as the root of rated power times resistance, or the tabulated maximum, whichever is lower. The other 43,783 rows outside WR and MR sit at sizes where neither sheet prints a ceiling at all.

Which series groups account for the 31,665 rows?

Nine of the twelve groups, and the share sits between 23 and 27 percent in seven of them. We grouped the 127,779 rows by series group and counted the rows above the ceiling for their own case size. The two groups that never exceed it are the current sense families, whose largest implied voltage is 0.83 V. The group that always exceeds it is the high ohm family.

Series group	Rows tested	Rows above the ceiling	Share	Largest implied voltage	Match / mismatch against a power-limited part
High Precision Thick Film	45,565	10,492	23.0%	2,236 V	Mismatch on 10,492 rows
High Power	29,018	6,977	24.0%	3,536 V	Mismatch on 6,977 rows
High Voltage	12,008	5,478	45.6%	5,000 V	Mismatch on 5,478 rows, the highest share outside high ohm
General Purpose, non-WR/MR prefix	8,990	2,238	24.9%	2,236 V	Mismatch on 2,238 rows
Anti-Surge	12,358	3,120	25.2%	3,317 V	Mismatch on 3,120 rows
Chip Resistor Array	6,296	1,503	23.9%	1,000 V	Mismatch on 1,503 rows
Array, anti-sulfuration	2,768	734	26.5%	316 V	Mismatch on 734 rows
Trimmable	2,433	635	26.1%	1,581 V	Mismatch on 635 rows
High Ohm (above 10 megohm)	488	488	100.0%	5,000 V	Mismatch on every row
Low Ohm Current Sense, thick film	7,297	0	0.0%	0.83 V	Match: power-limited on every row
Low Ohm Current Sense, metal	461	0	0.0%	0.79 V	Match: power-limited on every row
Resistor Network	97	0	0.0%	79 V	Match: power-limited on every row

We have not seen this counted anywhere. The proportion barely moves between families: 23.0 to 26.5 percent in seven of them. It is a property of the ladder, not of the series. Any ladder that runs from 1 ohm to 10 megohm at a fixed wattage crosses its voltage ceiling somewhere in the top decades.

What does a 100 percent result on the high ohm series actually tell you?

That the series cannot be power-limited at any resistance it offers. All 488 rows in Thick_Film_High_Ohm_Chip_Resistor_10M__1of1.xlsx start at 1.1 megohm or above. The lowest implied voltage in the whole series is 331.7 V, on WF06G115 JTL, which is already 1.66 times the highest ceiling printed in either sheet. The highest is 5,000 V.

Case size	Rows	Rated power	Resistance span	Implied voltage, lowest to highest	Match / mismatch against the sheets’ highest ceiling (200 V)
0402 (1005)	11	1/16 W	11 to 30 megohm	829 to 1,369 V	Mismatch on all 11
0603 (1608)	159	1/10 W	1.1 to 100 megohm	332 to 3,162 V	Mismatch on all 159
0805 (2012)	159	1/8 W	1.1 to 100 megohm	371 to 3,536 V	Mismatch on all 159
1206 (3216)	159	1/4 W	1.1 to 100 megohm	524 to 5,000 V	Mismatch on all 159

An 0402 part rated 1/16 W at 30 megohm implies 1,369 V. The number is arithmetic, and the arithmetic has stopped describing the part. For the range itself, see chip resistors above 10 megohm.

What does implied voltage say about the High Voltage series at 2010 and 2512?

Nothing we can test. The High Voltage group has 20,244 rows across five case sizes, and 8,236 of them are at 2010 and 2512, where neither sheet prints any ceiling. We opened the Thick_Film_High_Voltage_Chip_Resistor_*.xlsx files and counted the rows whose implied voltage exceeds 200 V, the highest ceiling either sheet prints: 8,835 of 20,244, or 43.6 percent, and the share climbs with the case.

Case size	Rows	Rated power	Rows above 200 V	Share	Largest resistance	Implied voltage at that resistance	Match / mismatch against a ceiling we can cite
0603 (1608)	3,924	1/10 W	1,313	33.5%	22 megohm	1,483 V	Mismatch: 75 V printed for the size
0805 (2012)	3,966	1/8 W	1,454	36.7%	51 megohm	2,525 V	Mismatch: 150 V printed for the size
1206 (3216)	4,118	1/4 W	1,794	43.6%	100 megohm	5,000 V	Mismatch: 200 V printed for the size
2010 (5025)	4,118	1/2 W	2,039	49.5%	100 megohm	7,071 V	No ceiling printed: cannot be tested
2512 (6432)	4,118	1 W	2,235	54.3%	100 megohm	10,000 V	No ceiling printed: cannot be tested

WK12V1623DTL is among the lowest-resistance 1206 High Voltage rows to cross 200 V: 162 kilohm at 1/4 W implies 201.2 V. At 160 kilohm the same body implies exactly 200.0 V. The High Voltage series exists to carry more volts than its general purpose neighbour, and the export gives the buyer no field to say how many. Our earlier post on high voltage chip resistors sets out why there is no voltage column to search.

Can an implied voltage tell a High Voltage part from a General Purpose one?

No, and the count is exact. We matched every row in the Thick_Film_High_Voltage_Chip_Resistor_*.xlsx files against the Thick_Film_General_Purpose_*.xlsx files on case size, resistance, tolerance, TCR and rated power. 11,773 of 20,244 High Voltage rows, 58.2 percent, share all five fields with a General Purpose row, so the root of power times resistance is identical to the last digit. The formula cannot see the difference between the two series.

Field	WR12X1004FTL	WK12V1004FTL	Match / mismatch	Your incumbent part (fill in)
Series group	General Purpose	High Voltage	Mismatch
Size	1206 (3216)	1206 (3216)	Match
Resistance	1 megohm	1 megohm	Match
Tolerance	±1%	±1%	Match
Rated power	1/4 W	1/4 W	Match
Implied voltage	500 V	500 V	Match
Voltage rating	200 V, from the WR sheet	not in any document we hold	Mismatch

A buyer who filters on size, value, tolerance and wattage receives both parts. One has a ceiling in print and one has none we can show you. 11,773 High Voltage rows are indistinguishable from a General Purpose row on every field the export carries, and the voltage that separates them is the one field it omits.

What should a design do with a number that is not a rating?

Treat it as the upper bound the part can never reach, and ask for the sheet. The crossover resistance is the ceiling squared divided by rated power: 160 kilohm at 1206 and 1/4 W, 56.25 kilohm at 0603 and 1/10 W. Above it, power stops mattering. On a 1 megohm part at 1206, the printed 1/4 W can never be dissipated.

1. Compute the crossover for your own case size and wattage. If your working resistance sits above it, the ceiling governs.
2. Ask for the governing sheet by part number. We hold 28 Walsin datasheets, 451 pages, and two are chip resistor sheets. For High Voltage, High Ohm, High Power, Anti-Surge, Trimmable and array parts we hold none, and we will tell you so the same day.
3. Cross the line in one pass. Paste up to 500 part numbers into the free cross-reference tool; each result names what matches and what does not.
4. Check what is held in Hong Kong on ready stock: 1,125 part numbers as at 23 September 2026, a dated snapshot. The range sits on the chip resistor page.

Confirm against both datasheets and qualify in your own circuit. Whether a series other than WR and MR carries a ceiling is a question for the manufacturer’s sheet, and the export cannot answer it.

The short version

Chip resistor implied working voltage is arithmetic, not a rating. We computed the root of power times resistance on 127,779 Walsin rows outside WR and MR and found 31,665 above the WR and MR ceiling for their case size: 24.8 percent. High Ohm: 488 of 488. High Voltage: 5,478 of 12,008, and 8,236 rows at 2010 and 2512 with no ceiling to test against. Current sense families: zero, largest 0.83 V. 11,773 High Voltage rows match a General Purpose row on every exported field. We will not tell you what a High Voltage part is rated for. We will show you what the export holds and what it leaves out. Qualification stays with you.

Send us the voltage line off your specification and the part numbers you filtered to, and we will tell you which rows have a printed ceiling and which do not. And a question back: when your selector returned a 1 megohm part at 1/4 W, did you read the wattage or the volts?

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Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"What is implied working voltage on a chip resistor?","content":"It is the square root of rated power times resistance. A 1206 part at 1 megohm and 1/4 W implies 500 V. Walsin's WR and MR sheets cap the real working voltage at the lower of that figure and a case-size ceiling, 200 V at 1206, so the implied value is an upper bound and never a rating.","visible":true},{"id":"faq-question-02","title":"Does the Walsin chip resistor export list a voltage rating?","content":"No. We read all ten columns across 234,401 distinct part numbers: part number, series group, series, size, resistance, tolerance, TCR, rated power, packaging and termination. None is a voltage. The ceilings exist only in the WR and MR approval sheets, which cover 62,692 of the 234,254 resistive rows.","visible":true},{"id":"faq-question-03","title":"How many Walsin rows imply a voltage above the case-size ceiling?","content":"Outside WR and MR, 31,665 of 127,779 rows tested, or 24.8 percent, at 0402 to 1210. Within that, 6,230 of 20,175 at 0402, 9,735 of 34,608 at 0603, 6,504 of 30,286 at 0805, 6,438 of 29,525 at 1206 and 2,758 of 13,185 at 1210.","visible":true},{"id":"faq-question-04","title":"Which Walsin chip resistors can never be power-limited?","content":"The high ohm series. All 488 rows begin at 1.1 megohm, and the lowest implied voltage is 331.7 V on WF06G115 JTL. The 0402 rows run from 829 to 1,369 V. A part in that range is governed by its voltage rating, not its wattage, at every value offered.”,”visible”:true},{“id”:”faq-question-05″,”title”:”Which Walsin series never exceed the case-size ceiling?”,”content”:”The current sense and network families. Thick film low ohm current sense reaches 0.83 V across 7,297 rows, metal low ohm 0.79 V across 461, and the resistor network 79 V across 97. For those, the printed wattage is the limit and the voltage ceiling does not bind.”,”visible”:true},{“id”:”faq-question-06″,”title”:”Can I tell a High Voltage part from a General Purpose one by its rated power?”,”content”:”No. 11,773 of 20,244 High Voltage rows, 58.2 percent, share case size, resistance, tolerance, TCR and rated power with a General Purpose row. The exported fields are identical and the series name is the only difference. We hold no High Voltage datasheet, so we cannot state its ceiling.”,”visible”:true},{“id”:”faq-question-07″,”title”:”Does the 200 V ceiling at 1206 apply to every Walsin 1206 resistor?”,”content”:”No. It is printed in the WR and MR sheets for those two series. We hold no sheet for High Voltage, High Power, High Ohm, Anti-Surge or the other series, and we do not extend the figure to them. Ask for the sheet covering your exact part number and qualify against it.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

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