MELF
Resistors
WRM Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
© TT electronics plc
11.12
· High reliability
· Predictable pulse handling capability
· Tolerances down to 0.1%
· TCR down to 5 ppm/°C
Dimensions (mm) and weight (g)
Type L D D1K Weight
max max max min
WRM 0102 2.2 1.35 1.3 0.3 0.01
WRM 0204 3.7 1.55 1.55 0.5 0.02
WRM 0207 6.1 2.4 2.4 0.5 0.08
MELF
Resistors
WRM Series
sHigh reliability
sPredictable pulse handling capability
sTolerances down to 0.1%
sTCR down to 5 ppm/°C
General Note
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to Welwyn’s own data and is considered accurate at time of going to print.
© Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
WRM 0102 WRM 0204 WRM 0207
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M10
–
61RM5 1
–
R22
4R7 - 110K
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Standard values E24 & E96
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Electrical Data
Physical Data
01. 11
A subsidiary of
TT electronics plc
Welwyn Components
L
K
L1
D
D1
Construction
A metal film is deposited onto a high dissipation ceramic
former to which tin plated teminating caps are fitted.
The resistor is adjusted to value by a helical cut in the film
and the body is protected by a lacquer coating.
Marking
Resistance values are colour coded with four bands,
three indicating value and one indicating the multiplier.
(Note this describes standard marking, but certain values
may still be supplied with the addition of a tolerance band
following the multiplier.)
Terminations
Material Plated steel cap.
Solderability The pure tin finish produces ageing free
contacts on which low melting solders can
be used. Dipped area shall be covered with
a smooth and bright solder coating after
3 seconds immersion at 215°C.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuit boards.
,01 ,51
MELF
Resistors
WRM Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
© TT electronics plc
11.12
MELF
Resistors
WRM Series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com 01.11
Welwyn Components
* Resistors to be mounted on a PC-board according to IEC 115-1, clause 4.27.1
Performance Data
Test Results ∆R/R ±
0204 & 0207: 10R - <75R
& >100K - 332K
0102: 4R7 - 110K, 0204 &
0207: R22 - <10R & >332K - 10M
0204 & 0207: 75R - 100K
Short time overload* ≤0.05% + 0.01 Ω ≤ 0.1% + 0.01 Ω ≤ 0.25% + 0.05 Ω
Bending test* ≤0.05% + 0.01 Ω ≤ 0.1% + 0.01 Ω ≤ 0.25% + 0.05 Ω
Resistance to soldering heat ≤0.05% + 0.01 Ω ≤ 0.1% + 0.01 Ω ≤ 0.25% + 0.05 Ω
Temperature rapid change ≤0.05% + 0.01 Ω ≤ 0.1% + 0.01 Ω ≤ 0.25% + 0.05 Ω
Endurance*
Load life 1000h ≤0.25% + 0.05 Ω ≤ 0.25% + 0.05 Ω ≤ 0.5% + 0.05 Ω
8000 h ≤0.5% + 0.05 Ω ≤ 0.5% + 0.05 Ω ≤ 1.0% + 0.05 Ω
Climatic sequence* ≤0.25% + 0.05 Ω ≤ 0.5% + 0.05 Ω ≤ 1.0% + 0.05 Ω
Damp heat steady state* ≤0.25% + 0.05 Ω ≤ 0.5% + 0.05 Ω ≤ 1.0% + 0.05 Ω
V/Vµ 3 <V/Vµ 52.0 <V/Vµ 50.0 <esion tnerruC
htooms a htiw derevoc eb llahs aera deppiDytilibaredloS
and bright solder coating of at least 96%
01 . 5.0 <tneiciffeoc egatloV 6/V
foorp egatloV No flashover or breakdown
±25ppm – – 10R – 500K
TCR and Tolerance Range
* TC 10ppm & 5ppm is specified over the temperature range -10°C to +85°C.
ecnareloTRCTepyT
Reference
5% 2% 1.0% 0.5% 0.25% 0.1%
±50ppm 4R7 - 110K
– – – – –
WRM0102
–––––
±50ppm – – 1R – 5M1 10R – 1M6 22R – 332K 43R – 332K
±100ppm R22 – R91
WRM0204 ±25ppm – – 4R7 - 500K 10R – 500K 22R – 402K 43R – 332K
±15ppm – – – 10R – 221K 22R – 221K 43R – 221K
±10ppm – ––– 22R – 221K 43R – 221K
±05ppm – ––– 100R – 100K 100R – 100K
±50ppm – – R16-10M 10R – 1M6 – –
±100ppm R22 – R91 –
WRM0207
±15ppm – ––
––––
10R - 1M 51R1 - 330K 100R - 100K
100R - 10K
51R1 - 10K
51R1 - 10K
MELF
Resistors
WRM Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
© TT electronics plc
11.12
MELF
Resistors
WRM Series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com 01.11
Welwyn Components
100
10
1
0,1
10 µs 100 µs 1 ms 10 ms 100 ms 1 s 10 s
Pulse Duration ti
Pulse Load Pmax
WRM 0102
WRM 0204
WRM 0207
W
100
10
1
0,1
10 µs 100 µs 1 ms 10 ms 100 ms 1 s 10 s
Pulse Duration ti
Continuous Pulse Load Pmax
WRM 0102
WRM 0204
WRM 0207
W
Single Pulse
Maximum Pulse Load
Continuous Pulses
Maximum Pulse Load
Type WRM 0204 C - 1K0 F I
Size
TCR
Value (use IEC62 code)
Note: F or zero-ohm versions order WRM0204C-R00FI or WRM0207C-R00FI
Tolerance (use IEC62 code)
Packing
C 50ppm/ºC T 10ppm/ºC
D 25ppm/ºC V 5ppm/ºC
Y 15ppm/ºC
Z 100ppm/ºC
B 0.1% D 0.5% G 2%
C 0.25% F 1% J 5%
0102 3000 / reel (7”)
ITape 0204 3000 / reel (7”)* Standard
0207 1500 / reel (7”)
Ordering Procedure
Example: WRM0204 at 1 kilohm, 1% tolerance and 50ppm/ºC TCR on a reel of 3000 pieces -
* High precision parts may be supplied on 1000 piece reels – please enquire
Packaging
The WRM 0102 and 0204 resistors are supplied reeled on 8mm blister tape.
WRM 0207 resistors are supplied on 12mm blister tape.
Packaging complies with the requirements of IEC 286-3.
MELF
Resistors
WRM Series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com 01.11
Welwyn Components
100
10
1
0,1
10 µs 100 µs 1 ms 10 ms 100 ms 1 s 10 s
Pulse Duration ti
Pulse Load Pmax
WRM 0102
WRM 0204
WRM 0207
W
100
10
1
0,1
10 µs 100 µs 1 ms 10 ms 100 ms 1 s 10 s
Pulse Duration ti
Continuous Pulse Load Pmax
WRM 0102
WRM 0204
WRM 0207
W
Single Pulse
Maximum Pulse Load
Continuous Pulses
Maximum Pulse Load
Type WRM 0204 C - 1K0 F I
Size
TCR
Value (use IEC62 code)
Note: F or zero-ohm versions order WRM0204C-R00FI or WRM0207C-R00FI
Tolerance (use IEC62 code)
Packing
C 50ppm/ºC T 10ppm/ºC
D 25ppm/ºC V 5ppm/ºC
Y 15ppm/ºC
Z 100ppm/ºC
B 0.1% D 0.5% G 2%
C 0.25% F 1% J 5%
0102 3000 / reel (7”)
ITape 0204 3000 / reel (7”)* Standard
0207 1500 / reel (7”)
Ordering Procedure
Example: WRM0204 at 1 kilohm, 1% tolerance and 50ppm/ºC TCR on a reel of 3000 pieces -
* High precision parts may be supplied on 1000 piece reels – please enquire
Packaging
The WRM 0102 and 0204 resistors are supplied reeled on 8mm blister tape.
WRM 0207 resistors are supplied on 12mm blister tape.
Packaging complies with the requirements of IEC 286-3.
MELF
Resistors
WRM Series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com 01.11
Welwyn Components
100
10
1
0,1
10 µs 100 µs 1 ms 10 ms 100 ms 1 s 10 s
Pulse Duration ti
Pulse Load Pmax
WRM 0102
WRM 0204
WRM 0207
W
100
10
1
0,1
10 µs 100 µs 1 ms 10 ms 100 ms 1 s 10 s
Pulse Duration ti
Continuous Pulse Load Pmax
WRM 0102
WRM 0204
WRM 0207
W
Single Pulse
Maximum Pulse Load
Continuous Pulses
Maximum Pulse Load
Type WRM 0204 C - 1K0 F I
Size
TCR
Value (use IEC62 code)
Note: F or zero-ohm versions order WRM0204C-R00FI or WRM0207C-R00FI
Tolerance (use IEC62 code)
Packing
C 50ppm/ºC T 10ppm/ºC
D 25ppm/ºC V 5ppm/ºC
Y 15ppm/ºC
Z 100ppm/ºC
B 0.1% D 0.5% G 2%
C 0.25% F 1% J 5%
0102 3000 / reel (7”)
ITape 0204 3000 / reel (7”)* Standard
0207 1500 / reel (7”)
Ordering Procedure
Example: WRM0204 at 1 kilohm, 1% tolerance and 50ppm/ºC TCR on a reel of 3000 pieces -
* High precision parts may be supplied on 1000 piece reels – please enquire
Packaging
The WRM 0102 and 0204 resistors are supplied reeled on 8mm blister tape.
WRM 0207 resistors are supplied on 12mm blister tape.
Packaging complies with the requirements of IEC 286-3.
MELF
Resistors
WRM Series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com 01.11
Welwyn Components
100
10
1
0,1
10 µs 100 µs 1 ms 10 ms 100 ms 1 s 10 s
Pulse Duration ti
Pulse Load Pmax
WRM 0102
WRM 0204
WRM 0207
W
100
10
1
0,1
10 µs 100 µs 1 ms 10 ms 100 ms 1 s 10 s
Pulse Duration ti
Continuous Pulse Load Pmax
WRM 0102
WRM 0204
WRM 0207
W
Single Pulse
Maximum Pulse Load
Continuous Pulses
Maximum Pulse Load
Type WRM 0204 C - 1K0 F I
Size
TCR
Value (use IEC62 code)
Note: F or zero-ohm versions order WRM0204C-R00FI or WRM0207C-R00FI
Tolerance (use IEC62 code)
Packing
C 50ppm/ºC T 10ppm/ºC
D 25ppm/ºC V 5ppm/ºC
Y 15ppm/ºC
Z 100ppm/ºC
B 0.1% D 0.5% G 2%
C 0.25% F 1% J 5%
0102 3000 / reel (7”)
ITape 0204 3000 / reel (7”)* Standard
0207 1500 / reel (7”)
Ordering Procedure
Example: WRM0204 at 1 kilohm, 1% tolerance and 50ppm/ºC TCR on a reel of 3000 pieces -
* High precision parts may be supplied on 1000 piece reels – please enquire
Packaging
The WRM 0102 and 0204 resistors are supplied reeled on 8mm blister tape.
WRM 0207 resistors are supplied on 12mm blister tape.
Packaging complies with the requirements of IEC 286-3.
