MF
MFS
RK
features
•Semi-precision metal film resistors
•The discharge path resistor is recognized by UL 1676 and
c-UL (CAS-C22.2 No.1-M94). (File No. E159326) (RK only)
•Meets requirements of MIL-R-22684
•Suitable for automatic machine insertion
•MFS two times the power rating of the standard body type
•Marking: Blue-gray body color with color-coded bands
•Products with lead-free terminations meet EU RoHS
and China RoHS requirements
MF, MFS, RK
general purpose metal film leaded resistor
dimensions and construction
Ceramic Core
d
D
Marking Resistive
Film
Insulation Coating
Trimming Line
End
Cap Lead
Wire
L l
C
L (ref.)
MF1/4 .248±.02
(6.3±0.5) .280
(7.1) .091±.012
(2.3±0.3) .024
(0.6) 1.18±.118
(30.0±3.0)
.024
(0.6)
.138±.016
(3.5±0.4)
.437
(11.1)
.354±0.4
(9.0±1.0)
MF1/2
Type C (max.) D d (nom.) l*
Dimensions inches (mm)
1/4: T26, T52, VT, VTP,
VTE, MT, M, U,
M10, M12.5
1/2: T26, T52, VTP,
VTE, M12.5, M15
1: T521
ordering information
+2%: 2 signifi-
cant figures +
1 multiplier
+0.5%,+1%:
3 significant
figures + 1
multiplier
“R” indicates
decimal on
value <100Ω
1/4: 0.25W
1/2: 0.50W
1: 1W
C: SnCu B: ±0.1%
C: ±0.25%
D: ±0.5%
F: ±1%
G:±2%
J: ±5%
MF 1/4 C
Termination
Material
Type Power
Rating Nominal
Resistance ToleranceTaping and Forming
New Part # T52 R20
A: Ammo
R: Reel
Packaging
R J
For further information on packaging,
please refer to Appendix C.
E: ±25
C: ±50
D: ±100
L: ±200
G:±250
B: ±350
T.C.R.
L
MFS1/4 .126±.008
(3.2±0.2) .133
(3.4) .018
(0.45)
.024
(0.6)
.091±.012
(2.3±0.3)
.280
(7.1)
.248±.02
(6.3±0.5)
MFS1/2
.066 +.007
-.004
(1.7 +0.2)
-0.1
.031
(0.8) 1.50±.118
(38.0±3.0)
1.50±.118
(38.0±3.0)
.217±.02
(5.5±0.5)
.721
(18.3)
.610±.02
(15.5±0.5)
MF1
EU
RK1/4 .248±.02
(6.3±0.5) .280
(7.1) .091±.012
(2.3±0.3) .024
(0.6)
.024
(0.6)
.138±.016
(3.5±0.4)
.437
(11.1)
.374±.04
(9.5±1.0)
RK1/2
.031
(0.8)
.217±.02
(5.5±0.5)
.720
(18.3)
.610±.04
(15.5±1.0)
RK1
0.94 min.
(24.0 min.)
Absolute
Maximum
Overload
Voltage
Absolute
Maximum
Working
Voltage
Part
Designation
Power
Rating
@ 70°C
applications and ratings
Minimum
Dielectric
Withstanding
Voltage
T.C.R.
(ppm/°C)
Resistance Range (Ω)
(B±0.1%)
E-96
(C±0.25%)
E-96
(D±0.5%)
E-24 E-192
(F±1.0%)
E-24 E-96
Operating
Temperature
Range
(G±2.0%)
E-24
(J±5.0%)
E-24
MFS1/4C
MFS1/4D 0.25W 49.9 -
562k 10 - 1M
D: ±100
C: ±50
300V ——— — 250V 300V -55°C
to
+155°C
Derating Curve
% Rated Power
100
80
60
40
20
-60 -40 0 406080100160
70
20
Ambient Tem pe rature
(°C)
0
-55
120
155
-20 140
Surface Temperature Rise
Temperature Rise (°C)
70
50
40
30
20
0 25 50 75
% Rated Power
0100
10
60
MFS1/2
MF1/2
MF1/4
MFS1/4
MF1
* Lead length changes depending on taping and forming.
107
KOA Speer Electronics, Inc. • 199 Bolivar Drive • Bradford, PA 16701 • USA • 814-362-5536 • Fax: 814-362-8883 • www.koaspeer.com
Specifications given herein may be changed at any time without prior notice. Please confirm technical specifications before you order and/or use. 2/01/11
resistors
108 KOA Speer Electronics, Inc. • 199 Bolivar Drive • Bradford, PA 16701 • USA • 814-362-5536 • Fax: 814-362-8883 • www.koaspeer.com
Specifications given herein may be changed at any time without prior notice. Please confirm technical specifications before you order and/or use. 2/01/11
resistors
MF, MFS, RK
general purpose metal film leaded resistor
Performance Characteristics
environmental applications
Absolute
Maximum
Overload
Voltage
Absolute
Maximum
Working
Voltage
Part
Designation
Power
Rating
@ 70°C
applications and ratings
Minimum
Dielectric
Withstanding
Voltage
MF1/4C
MF1/4D
MF1/2D
MF1/2C
MF1D
MF1C
MF1E
0.25W
0.50W
1W
——
10- 2.21M
10 - 5.05M
10Ω - 5.11M
47.5 - 4.64M 47.5 - 5.11M
1.0 - 6.81M
10 - 4.99M
10 - 5.11M
10 - 2.21M
——
——
47.5Ω - 1.0M 47.5 - 2.49M
47.5 - 1.0M 47.5 - 2.49M
——
——
D: ±100
C: ±50
C: ±50
D: ±100
E: ±25
C: ±50
D: ±100
700V
500V 250V
350V
500V
700V
T.C.R.
(ppm/°C)
Resistance Range (Ω)
(B±0.1%)
E-96
(C±0.25%)
E-96
(D±0.5%)
E-24 E-192
(F±1.0%)
E-24 E-96
Operating
Temperature
Range
-55°C
to
+155°C
—
—
—
—
(G±2.0%)
E-24
—
—
—
—
(J±5.0%)
E-24
MF1/4L
1.0 - 10
L: ±200
0.51 - 10
———
MF1/2L —
1.0 - 10
L: ±200
0.51 - 10Ω
——
350V 700V700V
MFS1/2D
MFS1/2C
10 - 1M 10 - 2.21M
——
C: ±50
D: ±100
500V0.50W 350V 700V
10 - 2.2M
—
RK1/2D
0.50W
—
—
5.11M - 33M
—
——
——
——
L: ±200
L: ±200
D: ±100 —
3.3M - 33M
—
3.3M - 33M
RK1/4D —
3.09M - 25M
D: ±100 — —
——
700V 1000V700V
0.25W 500V
—
—
500V 700V
6.2M - 33M 6.2M - 33M
RK1/4L
—
100k - 25M
——B: ±350
100k - 33M 100k - 33M
RK1/4B
RK1/2L
RK1BC 1W
—
100k - 51M
——
——
G: ±250
B: ±350
100k - 100M 100k - 100M
1000V 1500V1000V
0.50W 350V 700V700V
—
——
1M - 12M
—
100k - 35M
——B: ±350
100k - 51M 100k - 51M
RK1/2B
RK1/2G*
* Discharge path resistor
Parameter
Requirement ∆R ±(% + 0.05Ω)
Limit Typical Test Method
Resistance
T.C.R.
25°C
Room temperature, +100°C
Within specified
tolerance
Within specified
T.C.R.
—
—
Overload (Short Time) Rated voltage x 2.5 or max. overload voltage for 5 seconds, whichever is less;
MFS1/2: Rated voltage x 2 or max. overload voltage for 5 seconds, whichever is less
RK: ±1%, RK1/2G: ±2.5%
MF: ±0.5%
RK: ±0.6%, RK1/2G: ±1%
MF: ±0.3%
Resistance to Solder Heat 260°C ± 5°C, 10 seconds ± 1 second or
350°C ± 10°C, 3.5 seconds ± 0.5 second
RK: ±1%; RK1/2G: ±5%;
MFS: ±0.75%; MF1/4,
MFS1/2, MF1/2: ±0.5%,
RK: ±0.5%; RK1/2G: ±1%
MFS1/4: ±0.4%; MF1/4,
MFS1/2, MF1/2: ±0.25%
Dielectric Withstanding Voltage 1 minute
No breakdown —
Insulation Resistance 100V, 1 minute
Not less than 10,000MΩ—
Rapid Change of Temperature -55°C (30 minutes), +155°C (30 minutes), 5 cycles
RK,MF: ±1%; RK1/2G: ±5%
MF: ±0.3%; RK: ±0.5%,
RK1/2G: ±1%
Moisture Resistance 40°C ± 2°C, 90 - 95% RH, 1000 hours, 1.5 hr ON, 0.5 hr OFF cycle
RK: ±5%; RK1/2G: ±10%;
MFS1/4: ±1.5%; MF1/4,
MFS1/2, MF1/2: ±1%
RK: ±2%; RK1/2G: ±5%;
MFS1/4: ±1%; MF1/4,
MFS1/2, MF1/2: ±0.75%
Endurance at 70°C 70°C ± 2°C, 1000 hours, 1.5 hr ON, 0.5 hr OFF cycle
RK: ±5%; RK1/2G: ±10%;
MFS1/4: ±1.5%; MF1/4,
MFS1/2, MF1/2: ±1%
RK: ±2%; RK1/2G: ±5%;
MFS1/4: ±1%; MF1/4,
MFS1/2, MF1/2: ±0.75%
Resistance to Solvent The resistor shall be immersed for 5 seconds in IPA
No abnormality in
appearance. Marking
shall be easily legible —
Impulse Discharge from 1000pF capacitor 50 pulses. Internal 2.5 seconds.
Charge voltage: 1.25kV (RK1/4), 2.5kV (RK1/2) and 6kV (RK1)
No such abnormalities
as short-circuit, burnout,
breakdown, etc. —
