MELF
MELF
Resistors
Resistors
WRM Series
WRM Series
High reliability
High reliability handling capability
Predictable pulse
Predictabledown to 0.1% capability
Tolerances pulse handling
Tolerances to 5 ppm/°C
TCR down down to 0.1%
TCR down to 5 ppm/°C
Welwyn Components
·
·
·
·
Electrical Data
WRM 0102
Power rating at 70°C
Resistance range
Limiting element voltage
TCR
Resistance tolerance
Standard values
Thermal impedance
Ambient temperature range
Insulation resistance
k/W
°C
ohms
250
watts
ohms
volts
ppm/°C
%
0.125
4R7 - 110K
150
50
1
WRM 0204
0.25
R22 – 5M1
200
5,10,15, 25, 50, 100
E24 & E96
200
-55 to +125
>10
10
140
WRM 0207
0.4
R16 – 10 M
250
15, 25, 50, 100
0.1, 0.25, 0.5, 1.0, 2, 5
Physical Data
Dimensions (mm) and weight (g)
Type
WRM 0102
WRM 0204
WRM 0207
L
max
2.2
3.7
6.1
D
max
1.35
1.55
2.4
D
1
max
1.3
1.55
2.4
K
min
0.3
0.5
0.5
Weight
0.01
0.02
0.08
L
D
1
L
1
K
D
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.
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.
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.)
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuit boards.
General Note
General Note
Welwyn Components reserves to right changes changes in product specification without liability.
TT electronics reserves the right themake to make in product specification without notice or notice or liability.
All information is subject to Welwyn’s own data and is considered accurate at at time of going to print.
All information is subject to TT electronics’ own data and is considered accuratetime of going to print.
A subsidiary of
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
TT electronics plc
© Welwyn Components Limited
· Bedlington, Northumberland NE22 7AA, UK
© TT electronics plc
822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
Telephone: +44 (0) 1670
01. 11
11.12
MELF
MELF
Resistors
Resistors
WRM Series
WRM Series
Welwyn Components
TCR and Tolerance Range
Type
Reference
5%
WRM0102
±50ppm
±100ppm
±50ppm
WRM0204
±25ppm
±15ppm
±10ppm
±05ppm
±100ppm
WRM0207
±50ppm
±25ppm
±15ppm
–
R22 – R91
–
–
–
–
–
R22 – R91
–
–
–
2%
–
–
–
–
–
–
–
–
–
–
–
1.0%
4R7 - 110K
–
1R – 5M1
4R7 - 500K
–
–
–
–
R16-10M
10R - 1M
–
0.5%
–
–
10R – 1M6
10R – 500K
10R – 221K
–
–
–
10R – 1M6
10R – 500K
51R1 - 10K
0.25%
–
–
22R – 332K
22R – 402K
22R – 221K
22R – 221K
100R – 100K
–
–
51R1 - 330K
51R1 - 10K
0.1%
–
–
43R – 332K
43R – 332K
43R – 221K
43R – 221K
100R – 100K
–
–
100R - 100K
100R - 10K
TCR
Tolerance
* TC 10ppm & 5ppm is specified over the temperature range -10°C to +85°C.
Performance Data
Test
0204 & 0207: 75R - 100K
Short time overload*
Bending test*
Resistance to soldering heat
Temperature rapid change
Endurance*
Load life
Climatic sequence*
Damp heat steady state*
Current noise
Solderability
Voltage coefficient
Voltage proof
1000h
8000 h
≤
0.25% + 0.05
Ω
≤
0.5% + 0.05
Ω
≤
0.25% + 0.05
Ω
≤
0.25% + 0.05
Ω
< 0.05 µV/V
≤
0.25% + 0.05
Ω
≤
0.5% + 0.05
Ω
≤
0.5% + 0.05
Ω
≤
0.5% + 0.05
Ω
< 0.25 µV/V
Dipped area shall be covered with a smooth
and bright solder coating of at least 96%
< 0.5 . 10
6
/V
No flashover or breakdown
≤
0.5% + 0.05
Ω
≤
1.0% + 0.05
Ω
≤
1.0% + 0.05
Ω
≤
1.0% + 0.05
Ω
< 3 µV/V
≤
0.05% + 0.01
Ω
≤
0.05% + 0.01
Ω
≤
0.05% + 0.01
Ω
≤
0.05% + 0.01
Ω
Results
∆
R/R ±
0204 & 0207: 10R - <75R
& >100K - 332K
≤
0.1% + 0.01
Ω
≤
0.1% + 0.01
Ω
≤
0.1% + 0.01
Ω
≤
0.1% + 0.01
Ω
0102: 4R7 - 110K, 0204 &
0207: R22 - <10R & >332K - 10M
≤
0.25% + 0.05
Ω
≤
0.25% + 0.05
Ω
≤
0.25% + 0.05
Ω
≤
0.25% + 0.05
Ω
* Resistors to be mounted on a PC-board according to IEC 115-1, clause 4.27.1
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.
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
© 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
© TT electronics plc
01.11
11.12
MELF
MELF
Resistors
MELF
MELF
Resistors
MELF
WRM Series
Resistors
Resistors
WRM Series
Resistors
WRM Series
WRM Series
WRM Series
Single Pulse
Single Pulse
Maximum Pulse Load
Maximum Pulse Load
Single Pulse
Single Pulse
Load
Maximum Pulse
100
Maximum Pulse Load
Welwyn
Welwyn
Welwyn
Welwyn
Components
Components
Components
Components
Pulse Load Load
max maxmax
Pulse Load
P
max
P P
Pulse Load
Pulse
P
100
W
100
W
100
10
W
10
W
10
10
1
1
1
1
0,1
0,1 10
µs
0,1 10
µs
0,1 10
µs
10
µs
100
µs
100
µs
100
µs
100
µs
1 ms
1 ms
1 ms
1 ms
10 ms
100 ms
1s
1s
1s
1s
WRM 0102
0204
WRM 0102
0207
WRM 0204
WRM 0102
WRM 0207
WRM 0102
0204
WRM 0204
0207
WRM 0207
10 s
10 s
10 s
10 s
Maximum Pulse Load
100
100
W
100
W
100
10
W
10
W
10
10
1
1
1
1
0,1
0,1 10
µs
0,1 10
µs
0,1 10
µs
10
µs
Continuous Pulse Load Load
P
max maxmax
Continuous Pulse Load
P
Load
P P
Continuous Pulse
Continuous Pulse
max
Continuous Pulses
Continuous Pulses
Maximum Pulse Load
Maximum Pulse
Pulses
Continuous
Load
Continuous Pulses
Maximum Pulse Load
Pulse Duration
10 ms
Pulse Duration
Pulse Duration
Pulse Duration
10 ms
10 ms
t
i
t
i
t
i
t
i
100 ms
100 ms
100 ms
WRM 0102
WRM 0204
0102
0207
WRM 0204
WRM 0102
WRM 0207
WRM 0102
0204
WRM 0204
0207
WRM 0207
100
µs
100
µs
100
µs
100
µs
1 ms
1 ms
1 ms
1 ms
10 ms
100 ms
1s
1s
1s
1s
10 s
10 s
10 s
10 s
Packaging
Pulse Duration
t
i
Packaging
and 0204 resistors are supplied reeled on 8mm blister tape.
Pulse Duration
t
i
The WRM 0102
The WRM 0102 and are supplied on 12mm blister tape. 8mm blister tape.
Packaging
WRM 0207 resistors 0204 resistors are supplied reeled on
Packaging
and are supplied on 12mm blister tape. 8mm blister tape.
WRM 0207 resistors 0204 resistors are supplied reeled on
The WRM 0102
Packaging complies are the requirements blister tape.
The WRM 0102 andwithsupplied on 12mmof IEC 286-3. 8mm blister tape.
WRM 0207 resistors 0204 resistors are supplied reeled on
Packaging complies withsupplied on 12mmof IEC 286-3.
WRM 0207 resistors are the requirements blister tape.
Packaging complies with the requirements of IEC 286-3.
Packaging complies with the requirements of IEC 286-3.
Pulse Duration
10 ms
Pulse Duration
10 ms
10 ms
t
i
t
i
100 ms
100 ms
100 ms
Ordering Procedure
Ordering Procedure
Example: WRM0204 at 1 kilohm, 1% tolerance and 50ppm/ºC TCR on a reel of 3000 pieces -
Ordering Procedure
tolerance and 50ppm/ºC TCR on a reel of 3000 pieces -
Example: WRM0204 at 1 kilohm, 1%
Ordering Procedure
Type
WRM
0204
C - 1K0
F
I
Example: WRM0204 at 1 kilohm, 1% tolerance and 50ppm/ºC TCR on a reel of 3000 pieces -
Example: WRM0204 at 1 kilohm, 1% tolerance and 50ppm/ºC TCR on a reel of 3000 pieces -
Type
WRM
0204
C - 1K0
F
I
Size
Type
WRM
0204
C - 1K0
F
I
Size
Type
WRM
0204
C - 1K0
F
I
TCR
Size
TCR
Size
0102
Z 100ppm/ºC Y 15ppm/ºC
TCR
100ppm/ºC Y 15ppm/ºC
0102
Z
I
Tape
0204
TCR
50ppm/ºC
T 10ppm/ºC
C
Z 50ppm/ºC
T 10ppm/ºC
C 100ppm/ºC Y 15ppm/ºC
V 5ppm/ºC
D 100ppm/ºC Y 15ppm/ºC
Z 25ppm/ºC
T 10ppm/ºC
C 50ppm/ºC
V 5ppm/ºC
D 25ppm/ºC
T 10ppm/ºC
C 50ppm/ºC
D 25ppm/ºC
Value (use IEC62
V 5ppm/ºC
code)
D 25ppm/ºC
Value (use IEC62
V 5ppm/ºC
code)
3000 / reel (7”)
3000 / reel (7”)
3000 / reel (7”)*
0102
(7”)
I
Tape
0204 3000 / reel (7”)*
Standard
0207 1500 / reel (7”)
0102 3000 / reel (7”)
I
Tape
0204 3000 / reel (7”)*
Standard
0207 1500
(7”)
* High precision parts may be supplied on 1000 piece reels – please enquire
I
Tape
0204 3000 / reel (7”)*
Standard
* High precision parts may be supplied on 1000
/
piece reels – please enquire
0207 1500 reel (7”)
0207 1500 / reel (7”)
* High precision parts may be supplied on 1000 piece reels – please enquire
* High precision parts may be supplied on 1000 piece reels – please enquire
Packing
Packing
Packing
Standard
Packing
B 0.25% F 1%
C 0.1% D 0.5% G 5%
J 2%
Note:
F or zero-ohm versions order
WRM0204C-R00FI
or
WRM0207C-R00FI
B 0.1% D 0.5% G 2%
C 0.25% F 1%
J 5%
Note:
F or zero-ohm versions order
WRM0204C-R00FI
or
WRM0207C-R00FI
0.25% F 1%
©
C
Welwyn Components
J 5%
Bedlington, Northumberland NE22 7AA, UK
Limited
Note:
F or zero-ohm versions order
WRM0204C-R00FI
or
WRM0207C-R00FI
General Note
1670 822181
Limited
Bedlington, Northumberland NE22 7AA, UK
01.11
Telephone: +44 (0)
© Welwyn Components
· Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
TT electronics reserves the
822181 · Facsimile: +44
in product
829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
01.11
Telephone: +44 (0) 1670
right to make changes
(0) 1670
specification without notice or liability.
© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA, UK
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
01.11
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA, UK
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
01.11
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
© TT electronics plc
11.12
Tolerance (use IEC62 code)
Value (use IEC62 code)
Tolerance (use IEC62 code)
Value (use IEC62 code)
B 0.1% D 0.5% G
Tolerance (use IEC62 code)
2%
B 0.1% D 0.5% G 2%
Tolerance (use IEC62 code)
5%
C 0.25% F 1%
J
Note:
F or zero-ohm versions order
WRM0204C-R00FI
or
WRM0207C-R00FI
