Mini Melf
Resistors
WRM Series
Welwyn Components
TCR and Tolerance Range
Type
TCR
Tolerance
Reference
5%
2%
1.0%
0.5%
0.25%
0.1%
WRM0102
WRM0102
WRM0102
WRM0102
WRM0102
WRM0204
WRM0204
WRM0204
WRM0204
WRM0204
WRM0207
WRM0207
WRM0207
WRM0207
WRM0207
50ppm
25ppm
15ppm
10ppm
05ppm
50ppm
25ppm
15ppm
10ppm
05ppm
50ppm
25ppm
15ppm
10ppm
05ppm
R22 – R91
IRO – 9R1
10R – 2.21M
47RS – 221K
100R – 221K
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
10R – 221K
47R5 – 221K
100R – 221K
100R – 100K
–
–
100R – 100K
100R – 100K
100R – 100K
–
–
–
–
–
–
–
–
–
–
R22 – R91
1R – 10M
10R – 475K
22R – 332K
43R – 332K
–
10R – 475K
10R – 475K
22R – 332K
43R – 332K
–
–
10R – 221K
22R – 221K
43R – 221K
–
–
–
22R – 221K
43R – 221K
–
–
–
100R – 100K
100R – 100K
R22 – R91
1R – 8.2M
10R – 1M
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
10R – 1M
–
–
–
* TC 10ppm & 5ppm is specified over the temperature range -10°C to +85°C.
Performance Data
Test
Results ∆ R/R
Stability class
Description
0.25
0.5
1.0
10 Ω – <75 Ω
0.22 Ω – <10 Ω
>332 kΩ – 10 MΩ
≤ 0.25% + 0.05 Ω
≤ 0.25% + 0.05 Ω
≤ 0.25% + 0.05 Ω
≤ 0.25% + 0.05 Ω
75 Ω – <100 kΩ
≤ 0.05% + 0.01 Ω
≤ 0.05% + 0.01 Ω
≤ 0.05% + 0.01 Ω
≤ 0.05% + 0.01 Ω
>100 kΩ – 332 kΩ
≤ 0.1% + 0.01 Ω
≤ 0.1% + 0.01 Ω
≤ 0.1% + 0.01 Ω
≤ 0.1% + 0.01 Ω
Short time overload*
Bending test*
Resistance to soldering heat
Temperature rapid change
Endurance*
Load life
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
≤ 1.0% + 0.05 Ω
≤ 1.0% + 0.05 Ω
≤ 1.0% + 0.05 Ω
< 3 µV/V
Climatic sequence*
Damp heat steady state*
Current noise
≤ 0.5% + 0.05 Ω
≤ 0.5% + 0.05 Ω
< 0.25 µV/V
Solderability
Dipped area shall be covered with a smooth
and bright solder coating of at least 96%
< 0.5 . 106/V
Voltage coefficient
Voltage proof
200V
300V
500V
* Resistors to be mounted on a PC-board according to IEC 115-1, clause 4.27.1
© 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
Issue D · 09.06
TTELEC [ TT Electronics ]
