Mini Melf
Resistors
WRM Series
Welwyn Components
TCR and Tolerance Range
Type
Reference
WRM0102
WRM0102
WRM0102
WRM0102
WRM0102
WRM0204
WRM0204
WRM0204
WRM0204
WRM0204
WRM0207
WRM0207
WRM0207
WRM0207
WRM0207
TCR
±50ppm
±25ppm
±15ppm
±10ppm
±05ppm
±50ppm
±25ppm
±15ppm
±10ppm
±05ppm
±50ppm
±25ppm
±15ppm
±10ppm
±05ppm
5%
R22 – R91
–
–
–
–
R22 – R91
–
–
–
–
R22 – R91
–
–
–
–
2%
IRO – 9R1
–
–
–
–
–
–
–
–
–
–
–
–
–
–
Tolerance
1.0%
10R – 2.21M
10R – 221K
–
–
–
1R – 10M
10R – 475K
–
–
–
1R – 8.2M
–
–
–
–
0.5%
47RS – 221K
47R5 – 221K
100R – 100K
–
–
10R – 475K
10R – 475K
10R – 221K
–
–
10R – 1M
10R – 1M
–
–
–
* TC 10ppm & 5ppm is specified over the temperature range -10°C to +85°C.
0.25%
100R – 221K
100R – 221K
100R – 100K
–
–
22R – 332K
22R – 332K
22R – 221K
22R – 221K
100R – 100K
–
–
–
–
–
0.1%
–
100R – 100K
100R – 100K
–
–
43R – 332K
43R – 332K
43R – 221K
43R – 221K
100R – 100K
–
–
–
–
–
Performance Data
Test
Description
Short time overload*
Bending test*
Resistance to soldering heat
Temperature rapid change
Endurance*
Load life
1000h
8000 h
Climatic sequence*
Damp heat steady state*
Current noise
Solderability
Voltage coefficient
Voltage proof
0.25
75 Ω – <100 kΩ
≤ 0.05% + 0.01 Ω
≤ 0.05% + 0.01 Ω
≤ 0.05% + 0.01 Ω
≤ 0.05% + 0.01 Ω
Results ∆ R/R ±
Stability class
0.5
10 Ω – <75 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
≤ 0.25% + 0.05 Ω
≤ 0.5% + 0.05 Ω
≤ 0.25% + 0.05 Ω
≤ 0.25% + 0.05 Ω
< 0.05 µV/V
200V
≤ 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 . 106/V
300V
* Resistors to be mounted on a PC-board according to IEC 115-1, clause 4.27.1
1.0
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
≤ 0.5% + 0.05 Ω
≤ 1.0% + 0.05 Ω
≤ 1.0% + 0.05 Ω
≤ 1.0% + 0.05 Ω
< 3 µV/V
500V
© 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