RTO 50
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Revision: 17-Oct-2018 1Document Number: 50035
For technical questions, contact: sferfixedresistors@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
50 W Power Resistor, Thick Film Technology, TO-220
DESIGN SUPPORT TOOLS
FEATURES
• 50 W at 25 °C heatsink mounted
• Adjusted by sand trimming
• Leaded or surface mount versions
• High power to size ratio
• Non inductive element
• Material categorization: for definitions of compliance
please see www.vishay.com/doc?99912
Because of the knowledge and experience in Thick Film technology, Vishay Sfernice has been able to develop a high power
resistor in a TO-220 package called RTO 50. The special design of this component allows the dissipation of 50 W when mounted
on a heatsink.
Note
(1) E24 series
Note
• Not compatible with RoHS reflow profile
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Available
Models
DIMENSIONS in millimeters
STANDARD ELECTRICAL SPECIFICATIONS
MODEL SIZE
RESISTANCE
RANGE
RATED POWER
P25 °C
W
LIMITING ELEMENT
VOLTAGE UL
V
TOLERANCE
± %
TEMPERATURE
COEFFICIENT
± ppm/°C
CRITICAL
RESISTANCE
RTO 50 TO-220 0.010 to 550K (1) 50 500 1, 2, 5, 10 150 5K
4.5
1.3
8.8
Ø 0.8
10.1
13.7
12.5
5.08
15
Ø 3.6
2.5
RTO 50F - LEADED
4.5
1.3
8.8
10.1
12.5
5.08
15
Ø 3.6
0.3
1.6
3
2
RTO 50C - FOR SURFACE MOUNTING
• Only for RTO 50 version C = during surface mount soldering, the
soldering temperature profile must not cause the metal tab of this
device to exceed 220 °C.
MECHANICAL SPECIFICATIONS
Mechanical Protection Molded
Resistive Element Thick film
Connections Tinned copper alloy
Weight 2.2 g max.
ENVIRONMENTAL SPECIFICATIONS
Temperature Range -55 °C to 155 °C
Climatic Category 55 / 155 / 156
Sealing Sealed container, solder immersion
Flammability IEC 60695-11-5,
2 applications 30 s separated by 60 s
TECHNICAL SPECIFICATIONS
Dissipation and Associated Onto a heatsink
Thermal Resistance
and Nominal Power
50 W at +25 °C
RTH (j - c): 2.6 °C/W
Free air: 2.25 W at +25 °C
Dielectric Strength
MIL STD 202 (301)
2000 VRMS - 1 min
10 mA max.
Insulation Resistance 106 M
Inductance 0.1 μH
DIMENSIONS
Standard Package TO-220 insulated case
RTO 50
www.vishay.com Vishay Sfernice
Revision: 17-Oct-2018 2Document Number: 50035
For technical questions, contact: sferfixedresistors@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
CHOICE OF THE HEATSINK
The user must choose according to the working conditions of the component (power, room temperature).
Maximum working temperature must not exceed 155 °C. The dissipated power is simply calculated by the following ratio:
P: Expressed in W
T: Difference between maximum working temperature and room temperature
RTH (j - c): Thermal resistance value measured between resistive layer and outer side of the resistor. It is
the thermal resistance of the component: (Special Features Table)
RTH (c - h): Thermal resistance value measured between outer side of the resistor and upper side of the
heatsink. This is the thermal resistance of the interface (grease, thermal pad), and the quality of
the fastening device
RTH (h - a): Thermal resistance of the heatsink
Example:
RTH (c - a): For RTO 50 power rating 13 W at ambient temperature +30 °C
Thermal resistance RTH (j - c): 2.6 °C/W
Considering equation (1) we have:
T 155 °C - 30 °C = 125 °C
RTH (j - c) + RTH (c - h) + RTH (h - a) = = = 9.6 °C/W
RTH (c - a) + RTH (h - a) 9 .6 °C/W - 2.6 °C/W 7 °C/W
PERFORMANCE
TESTS CONDITIONS REQUIREMENTS
Momentary Overload
EN 60115-1
2 Pr 5 s for R < 2
1.6 Pr 5 s for R 2
US < 1.5 UL
± (0.25 % + 0.05 )
Rapid Temperature Change
EN 60115-1
60 068-2-14
5 cycles -55 °C to +155 °C
± (0.5 % + 0.05 )
Load Life EN 60115-1
Pr at +25 °C, 1000 h CEI 115_1 ± (1 % + 0.05 )
Humidity (Steady State) EN 60115-1
56 days RH 95 % ± (0.5 % + 0.05 )
Vibration MIL STD 202
method 204 C test D ± (0.2 % + 0.05 )
Terminal Strength MIL STD 202
method 211 test A1 ± (0.2 % + 0.05 )
RESISTANCE VALUE IN RELATION TO TOLERANCE AND TCR
Resistance Values 0.01 0.015 0.1 0.5
Tolerances ± 1 % at ± 10 %
Temperature Coefficient
(-55 °C to +155 °C) Standard ± 900 ppm/°C ± 700 ppm/°C ± 250 ppm/°C ± 150 ppm/°C
PT
RTH (j - c) RTH (c - h) RTH (h - a)
++
----------------------- --------------------------- ------------------------------- ----------
1
=
T
P
-------
125
13
--------
RTO 50
www.vishay.com Vishay Sfernice
Revision: 17-Oct-2018 3Document Number: 50035
For technical questions, contact: sferfixedresistors@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
OVERLOADS
The applied voltage must always be lower than the
maximum overload voltage of 750 V.
The values indicated on the graph below are applicable to
resistors in air or mounted onto a heatsink.
MARKING
Model, style, resistance value (in ), tolerance (in %),
manufacturing date, Vishay Sfernice trademark.
ENERGY CURVE
POWER CURVE
POWER RATING
The temperature of the heatsink should be maintained within
the limits specified.
To improve the thermal conductivity, surfaces in contact
should be coated with a silicone grease and the torque
applied on the screw for tightening should be around 1 Nm.
0.001
0.01
0.1
1
10
100
ENERGY IN JOULES
OVERLOAD DURATION IN s
10-7 10-6 10-5 10-4 10-3 10-2 10-1
PACKAGING
Tube of 50 units
80
60
40
20
0
RATED POWER IN %
HEATSINK TEMPERATURE IN °C
0
100
20050 100 15025
RTO 50
www.vishay.com Vishay Sfernice
Revision: 17-Oct-2018 4Document Number: 50035
For technical questions, contact: sferfixedresistors@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
ORDERING INFORMATION
RTO 50 F 100K ± 1% XXX TU50 e1
MODEL STYLE CONNECTIONS
F: radial leads
C: surface mount
RESISTANCE VALUE TOLERANCE
± 1%
± 2%
± 5%
± 10%
CUSTOM DESIGN
optional
on request:
special TCR,
shape, etc.
PACKAGING LEAD (Pb)-FREE
GLOBAL PART NUMBER INFORMATION
GLOBAL
MODEL SIZE LEADS OHMIC VALUE TOLERANCE PACKAGING
RTO 050 F = radial leads
C = surface mount
The first four digits are significant
figures and the last digit
specifies the number of zeros
to follow.
R designates decimal point.
48R70 = 48.7
48701 = 48 700
10002 = 100 000
R0100 = 0.01
R6800 = 0.68
27000 = 2700 = 2.7 k
F = 1 %
G = 2 %
J = 5 %
K = 10 %
T = tube
Size 30 and 50:
tube 50 pieces
RELATED DOCUMENTS
APPLICATION NOTES
Potentiometers and Trimmers www.vishay.com/doc?51001
Guidelines for Vishay Sfernice Resistive and Inductive Components www.vishay.com/doc?52029
050FR680T1T OR 0JE
Legal Disclaimer Notice
www.vishay.com Vishay
Revision: 01-Jan-2021 1Document Number: 91000
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