Metal Film Resistors
Welwyn Components
MFR Series
•
•
•
Professional grade approved to
BSCECC 40101-803 and 019
Tolerances down to 0.5%
Temperature coefficient down to 50ppm/°C
Electrical Data
Power rating at 70°C
Resistance range
Limiting element voltage
TCR
Resistance tolerance
watts
ohms
volts
ppm/°C
%
MFR3
0.4
10R - 1M
200
50
1
MFR4
0.5
1R0 - 10M
350
50
0.5, 1,2
MFR5
0.75
1R0 - 1M
350
≤10:150
>10:100*
0.5, 1,2
* Note:- Tighter TCR’S are available on professional grade, consult factory for details.
Approved CECC 40101 - 019 Style
Power rating at 70°C
watts
Resistance range.
ohms
Limiting element voltage
volts
TCR
ppm/°C
Resistance tolerance
%
FZ
FX
0.25
0.25
1 to 1M
1 to 1M
250
250
100
250
5.1 to 9.1 : 200 5.1 to 9.1 : 500
1,2
1,2
BC
0.125
10 to 1M
200
50
0.5, 1, 2
BK
0.125
10 to 1M
200
100
0.5, 1, 2
EZ
0.5
10 to 1M0
350
100
1,2
CC
0.25
10 to 1M
250
50
0.5, 1, 2
EX
0.5
10 to 1M
350
250
1,2
CK
0.25
10 to 1M
250
100
0.5, 1, 2
Approved CECC 40101 - 803 Style
Power rating at 70°C
watts
Resistance range.
ohms
Limiting element voltage
volts
TCR
ppm/°C
Resistance tolerance
%
Standard values
Thermal impedance
Ambient temperature range
Product grades available
E24, E96 preferred
°C/watt
°C
150
commercial
140
-55 to 155
commercial, professional
112
Physical Data
Dimensions (mm) & Weight (g)
Type
MFR3
MFR4
MFR5
Professional
Commercial
Professional
Commercial
Professional
Commercial
L max
3.5
3.7
6.2
6.8
9.0
10.0
D max
1.8
2.0
2.5
3.0
3.6
3.7
F min
22.4
22.4
21.0
21.0
19.6
19.6
d nom
0.5
0.45
0.6
0.55
0.8
0.6
PCB
mount
centres
Min
bend
radius
Wt.
nom
7.6
7.6
10.2
10.2
12.7
12.7
0.5
0.5
0.6
0.6
1.2
0.6
0.1
0.1
0.3
0.3
0.5
0.5
d
D
L
f
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.
A subsidiary of
TT electronics plc
Issue D · 05.07
© 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
135
Metal Film Resistors
MFR Series
Welwyn Components
Performance Data - Type MFR 3
CECC 40101-019
Requirements
Load at commercial rating : 1000 hours at 70°C
Load at CECC rating :
1000 hours at 70°C
Shelf life :
12 months at room temperature
Derating
Short term overload
Climatic
Climatic category
Long term damp heat
Temperature rapid change
Resistance to solder heat
Vibration and bump
Noise. (in a decade of frequency)
Insulation resistance
Voltage proof
Pulse handling
R%
R%
R%
R%
R%
R%
R%
R%
R%
µV/V
ohms
volts
2
Not Specified
zero at 155°C
0.5
2
55/125/56
2
0.5
0.5
0.5
Not specified
>1G
350 min
Actual Performance
Maximum
Typical
0.8
See Graph 1
0.5
See Graph 1
0.1
0.07
0.25
0.5
0.5
0.25
0.25
0.1
0.1
>1G
400 min
Data available upon request
0.03
0.2
0.3
0.05
0.02
0.01
0.07
>1G
400 min
Graph 1 – Load for 1000 hours at 70°C: maximum changes
Performance Data - Type MFR 4
CECC 40101-019
Requirements
Load at commercial rating :
1000 hours at 70°C
Load at CECC rating :
1000 hours at 70°C
Shelf life :
12 months at room temperature
Derating
Short term overload
Climatic
Climatic category
Long term damp heat
Temperature rapid change
Resistance to solder heat
Vibration and bump
Noise. (in a decade of frequency)
Insulation resistance
Voltage proof
Pulse handling
R%
R%
R%
R%
R%
R%
R%
R%
R%
µV/V
ohms
volts
2
Not specified
zero at 155°C
0.5
2
55/125/56
2
0.5
0.5
0.5
Not Specified
>1G
500 min
1
Not Specified
CECC 40101-803
Requirements
Actual Performance
Maximum
Typical
0.8
0.5
0.1
See Graph 2
See Graph 2
0.07
0.01
0.2
0.3
0.04
0.07
0.01
0.1
>1G
500 min
zero at 155°C
0.25
0.25
1
0.5
55/125/56
1
0.5
0.25
0.25
0.25
0.25
0.25
0.1
Not Specified
0.1
>1G
>1G
400 min
500 min
Data available upon request
Graph 2 – Load for 1000 hours at 70°C: maximum changes
© 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
136
Issue D · 05.07
Metal Film Resistors
MFR Series
Welwyn Components
Performance Data - Type MFR 5
CECC 40101-019
Requirements
Load at commercial rating :
1000 hours at 70°C
Load at CECC rating :
1000 hours at 70°C
Shelf life :
12 months at room temperature
Derating
Short term overload
Climatic
Climatic category
Long term damp heat
Temperature rapid change
Resistance to solder heat
Vibration and bump
Noise. (in a decade of frequency)
Insulation resistance
Voltage proof
Pulse handling
R%
R%
R%
R%
µV/V
ohms
volts
R%
R%
R%
R%
R%
2
Not specified
zero at 155°C
0.5
2
55/125/56
2
0.5
0.5
0.5
Not Specified
>1G
700 min
1
Not Specified
zero at 155°C
0.25
1
55/125/56
1
0.25
0.25
0.25
Not Specified
>1G
500 min
0.5
0.25
0.25
0.1
0.1
>1G
700 min
0.3
0.04
0.07
0.01
0.07
>1G
700 min
0.25
0.5
0.01
0.2
CECC 40101-803
Requirements
Actual Performance
Maximum
Typical
0.9
0.5
0.1
See Graph 3
See Graph 3
0.07
Data available upon request
Graph 3 – Load for 1000 hours at 70°C: maximum changes
Packaging
All MFR resistors are supplied tape packed ready for loading
on to automatic sequencing and insertion machines.
Component wires will not protrude beyond the outside edge
of the tapes.
Alternative packaging available by request.
Construction
The resistance element is a precisely controlled thin film of
metal alloy sputtered on to a high purity ceramic core,
protected by a moisture-resistant, high dielectric strength
coating applied so that terminations remain completely clear.
Terminations
Material
Hot tin dipped copper wire
The terminations meet the requirements of
IEC 68.2.21
Strength
5
f
1
6
52
f
2
6
f
1
– f
2
≤
1.4 mm
Solderability
The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2
Marking
0.5% and 1% tolerance resistors are colour coded with 5
bands, 2% tolerance has 4. IEC 62 colours are used.
Lead Formed resistors can also be supplied. Standard options
of Lancet, Radial and Goalpost forming are available.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuits.
© 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 · 05.07
137
Metal Film Resistors
MFR Series
Ordering Procedure
Example: Professional grade MFR4 at 4.7 kilohms and 1% tolerance in ammo pack box of 5000 pieces -
MFR4 - 4K7
F
I
Type
Value (use IEC62 code)
Tolerance (use IEC62 code)
D
F
G
0.5%
1%
2%
Packing / Grade
C
MFR3, MFR4
Ammo
MFR5
MFR4
MFR5
5000/box
2500/box
5000/box
2500/box
CECC release is not available for commercial grade
CECC release is optionally available for professional grade *
I
* For CECC released product state on order the CECC number and style.
Example:
MFR4-4K7FI CECC40101-019 FZ
© 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 . 05.07
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