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)
.374±.04
(9.5±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, M25
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)
.031
(0.8)
.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-96
(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
MFS1/4L
2.2 - 2.2M
L: ±200
-55°C
to
+155°C
99
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. 1/13/09
resistors
Derating Curve
% Rated Power
100
80
60
40
20
-60 -40 0 406080100160
70
20
Ambient Temperature
(°C)
0
-55
120
155
-20 140
Surface Temperature Rise
Temperature Rise (°C)
70
50
40
30
20
0255075
% Rated Power
0100
10
60
MF1/2
MF1
MFS1/2,MF1/4,
MF1/2 (+2%&+5%)
MFS1/4
MF1/4
1733 Reader's Spreads pg1-203:document 1/27/09 4:08 PM Page 97
100 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. 1/09/09
resistors
MF, MFS, RK
general purpose metal film leaded resistor
Performance Characteristics
environmental applications
PMS 300 neg. Black neg.
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
MF1/4E
MF1/2D
MF1/2C
MF1/2E
MF1D
MF1C
MF1E
0.25W
0.50W
1W
24.3Ω- 750K 24.3 - 1.0M 10- 2.21M
30.1 - 1.0M
10 - 5.05M
47.5 - 2.0M
10Ω- 5.11M
47.5 - 4.64M 47.5 - 5.11M
1.0 - 6.81M
47.5 - 2.0M
10 - 4.99M
10 - 5.11M
30.1 - 1.0M
10 - 2.21M
30.1 - 750K 30.1 - 1.0M
47.5- 1.0M 47.5 - 1.5M
47.5Ω- 1.0M 47.5 - 2.49M
47.5 - 2.0M 7.5 - 2.49M
——
——
E: ±25
D: ±100
C: ±50
E: ±25
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-96
(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
30.1 - 750K 30.1 - 1.0M
———
47.5- 1.0M 47.5 - 1.5M
MF1/2L —
1.0 - 10
L: ±200
0.51 - 10Ω0.33 - 5.6M
——
350V 700V700V
MFS1/2D
MFS1/2C
10 - 1M 10 - 2.21M
——
C: ±50
D: ±100
500V
0.50W 350V 700V
10 - 2.2M
—
0.20 - 2.2M
MFS1/2L
2.2 - 2.2M
L: ±200
1.0 - 3.01M
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 1000V
500V
700V
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: ±2.5%
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. —
1733 Reader's Spreads pg1-203:document 1/27/09 4:08 PM Page 98
