Pulse Withstanding Fusible
Flameproof Metal Film Resistors
EMC Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
© TT electronics plc
08.12
· Two parallel resistance elements in a single chip
· Excellent pulse withstand performance
· Laser trimmed up to 0.5% tolerance
· Enhanced working voltage
· Enhanced power rating
· Pb-free terminations
Dimensions (mm) & Weight (g)
Type L max D max f min d nom
PCB
mount
centres
Min bend
radius Wt. nom
EMC2 10 4 27 0.8 18.4 1.2 0.55
Physical Data
Lf
D
d
EMC2
Power rating at 70°C Watts 2
Resistance range Ohms 4R7 – 68R
TCR (25 to 75°C) ppm/°C 100
Isolation Voltage Volts 500
Resistance Tolerance % 10, 20
Standard Values E12
Thermal Impedance °C/Watt 82
Ambient temperature range °C -55 to +155
Electrical Data
Construction
The metal film is deposited onto a high purity ceramic rod. End caps are force fitted and termination wires are welded
to the end caps. Finally, a cement protection is applied to the resistor body prior to marking with indelible ink. The cement
protection is applied in a manner that leaves the terminations completely clear. This permits a well-defined body length (clean
lead to clean lead dimension L).
Terminations
Material: Solder-coated copper wire
Strength: The terminations meet the requirements of IEC 68.2.21
Solderability: The terminations meet the requirements of IEC 115-1 Clause 4.17.3.2
Solvent Resistance
The body protection and marking are resistant to all normal industrial cleaning solvents suitable for printed circuits.
Single Rectangular Pulse
1
10
100
1000
10000
0.01 0.1110 100 1000 10000
Pulse Duration (ms)
Pk Power(W)
Single Rectangular Pulse
1
10
100
1000
10000
0.01 0.1110 100 1000 10000
Pulse Duration (ms)
Pk Power(W)
Single Rectangular Pulse
1
10
100
1000
10000
0.01 0.1 1 10 100 1000 10000
Pulse Duration (ms)
Pk Power(W)
IEC61000-4-5 1.2/50 s Pulse
0
100
200
300
400
500
600
700
010203040506070
Value(Ohms)
Pk Voltage(V)
IEC61000-4-5 1.2/50 s Pulse
0
100
200
300
400
500
600
700
010203040506070
Value(Ohms)
Pk Voltage(V)
IEC61000-4-5 1.2/50 s Pulse
0
100
200
300
400
500
600
700
010203040506070
Value(Ohms)
Pk Voltage(V)
Pulse Withstanding Fusible
Flameproof Metal Film Resistors
EMC Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
© TT electronics plc
08.12
Flammability
The resistor coating is UL94-V0 rated and will not burn or emit incandescent particles under any condition of applied
temperature or power overload.
Marking
EMC resistors are colour coded with five bands. Four of the bands indicate value and tolerance in accordance with
IEC62. Parts with 20% tolerance have no fourth band. A fifth yellow band denotes constant voltage fusibility.
Maximum
Load at Rated Power: 1000hrs @ 70°C ΔR% 5
Shelf life: 12 months at room temperature ΔR% 2
Derating from rated power at 70°C Zero at 155°C
Climatic ΔR% 3
Climatic Category 50/155/56
Temperature rapid change ΔR% 0.5
Resistance to solder heat ΔR% 0.5
Performance Data
Pulse Performance
Fusing Performance
EMC resistors fuse open circuit at overload powers
exceeding 60W within the time indicated on the Fusing
Characteristic. Their fusing performance at lower
overload powers is not specified.
EMC resistors fuse safely in the event of a 115Vrms /
240Vrms overload (line / mains short circuit condition)
without burning or emitting incandescent particles.
After fusing, the resistance is at least 100 times greater
than the original nominal value.
Fusing Characteristic
(Constant Voltage)
Initial Power (W)
Max. Fusing Time (s)
40 50 60 70 80 90 100
0
5
10
15
20
(4R7-8R2)
(10R-68R)
Pulse Withstanding Fusible
Flameproof Metal Film Resistors
EMC Series
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
© TT electronics plc
08.12
Application Notes
1. If the resistors are to dissipate full rated power, it is recommended that the terminations should not be soldered closer than
4mm from the body.
2. Due to operating temperature limits imposed by some PCB materials, derating may be necessary. An estimate of the
temperature rise to be expected can be calculated using the thermal impedance figures given under Electrical Data.
3. To protect against fire under all conditions of overload, a positive clearance of at least 13mm should be provided between the
body of the resistor and any combustible materials.
4. EMC resistors can also be supplied loose packed with radial, goalpost or lancet pre-formed leads, tape packed with radial pre-
formed leads, or in blister tape with Z-formed leads for SMD mounting. Consult factory for details.
Packaging
Our standard packaging for EMC is taped and boxed. The critical dimensions are shown in Figure 1. The component wires will
not protrude beyond the outside edge of the tapes. Alternative packaging is available by request.
mm EMC2
B 62
C 5
f 2
b
f1 f 2
Figure 1
Body location f1-f2 < 1.4mm
66
c
Ordering Procedure
Specify type reference, value and tolerance as shown in this example of EMC2 at 33Ω, 20%:
Standard Quantities Per Package
Type
EMC2 - 33R M I
Value (use IEC62 code)
Tolerance (use IEC62 code)
Packing
I Ammo EMC2 2000/box Standard
Type EMC2
Ammo Pack 2000
K 10%
M 20%
