RTO 50
Vishay Sfernice
50 W Power Resistor, Thick Film Technology, TO-220
FEATURE
•
50 W at 25 °C heatsink mounted
•
Adjusted by sand trimming
•
Leaded or surface mount versions
•
High power to size ratio
•
Non inductive element
•
Compliant to RoHS directive 2002/95/EC
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. The ohmic value is adjusted by sand trimming. This process does not generate hot spots as in laser trimming,
which could lead to microcracks on each side of the curve. This process improves the reliability and the stability of the resistor
and at the same time gives a good overload capability.
DIMENSIONS
in millimeters
RTO 50F - LEADED
4.5
10.1
Ø 3.6
1.3
RTO 50C - FOR SURFACE MOUNTING
4.5
10.1
Ø 3.6
1.3
12.5
15
8.8
12.5
15
8.8
2
3
13.7
1.6
5.08
0.3
Ø 0.8
5.08
2.5
• 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
Resistive Element
Connections
Weight
Molded
Thick film
Tinned copper alloy
2.2 g max.
ELECTRICAL SPECIFICATIONS
Resistance Range
Tolerances Standard
Dissipation and Associated
Thermal Resistance
and Nominal Power
Temperature Coefficient
Standard (- 55 °C; + 150 °C)
Limiting Element Voltage U
L
Dielectric Strength
MIL STD 202 (301)
Insulation Resistance
Inductance
Critical Resistance
0.010
Ω
to 550 kΩ serie E24
± 1 % to ± 10 %
Onto a heatsink
50 W at + 25 °C
R
TH (j - c)
: 2.6 °C/W
free air:
2.25 W at + 25 °C
See Performance table
± 150 ppm/°C
300 V
2000 V
RMS
- 1 min
10 mA max.
≥
10
6
MΩ
≤
0.1 µH
1.8 kΩ
DIMENSIONS
Standard Package
TO-220
Insulated case
ENVIRONMENTAL SPECIFICATIONS
Temperature Range
Climatic Category
Sealing
Flammability
- 55 °C to + 155 °C
55/155/156
Sealed container
Solder immersion
IEC 60695-11-5
2 applications 30 s
seperated by 60 s
Note
• Not compatible with RoHS reflow profile
Document Number: 50035
Revision: 31-Mar-10
For technical questions, contact:
sfer@vishay.com
www.vishay.com
37
RTO 50
Vishay Sfernice
50 W Power Resistor, Thick Film Technology, TO-220
PERFORMANCE
TESTS
CONDITIONS
EN 60115-1
2 Pr 5 s for R < 2
Ω
1.6 Pr 5 s for R
≥
2
Ω
U
S
< 1.5
U
L
EN 60115-1
60 068-2-14
5 cycles - 55 °C to + 155 °C
EN 60115-1
P
r
at + 25 °C, 1000 h CEI 115_1
EN 60115-1
56 days RH 95 %
MIL STD 202
Method 204 C Test D
MIL STD 202
Method 211 Test A1
REQUIREMENTS
± (0.25 % + 0.05
Ω)
Momentary Overload
Rapid Temperature Change
Load Life
Humidity (Steady State)
Vibration
Terminal Strength
± (0.5 % + 0.05
Ω)
± (1 % + 0.05
Ω)
± (0.5 % + 0.05
Ω)
± (0.2 % + 0.05
Ω)
± (0.2 % + 0.05
Ω)
RESISTANCE VALUE IN RELATION TO TOLERANCE AND TCR
Resistance Values
Tolerances
Temperature
Coefficient
(- 55 °C to + 155 °C)
Standard
± 900 ppm/°C
≥
0.01
Ω
≥
0.015
Ω
± 1 % at ± 10 %
± 700 ppm/°C
± 250 ppm/°C
± 150 ppm/°C
≥
0.1
Ω
≥
0.5
Ω
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:
(
1
)
ΔT
-
P
=
---------------------------------------------------------
[
R
TH (j - c)
+
R
TH (c - a)
]
P:
ΔT:
R
TH (j - c)
:
R
TH (c - a)
:
Expressed in W
Difference between maximum working temperature and room temperature
Thermal resistance value measured between resistive layer and outer side of the resistor. It is the thermal
resistance of the component: (Special Features Table)
Thermal resistance value measured between outer side of the resistor and room temperature. It is the
thermal resistance of the heatsink itself (type, shape) and the quality of the fastening device
Example:
R
TH (c - a)
: For RTO 50 power rating 13 W at ambient temperature + 30 °C
Thermal resistance R
TH (j - c)
: 26 °C/W
Considering equation (1) we have:
ΔT ≤
155 °C - 30 °C
≤
125 °C
P
ΔT
125
-
R
TH (j - c)
+ R
TH (c - a)
=
-------
=
---------
= 9.6 °C/W
R
TH (c - a)
≤
9 .6 °C/W - 2.6 °C/W
≤
7 °C/W
13
www.vishay.com
38
For technical questions, contact:
sfer@vishay.com
Document Number: 50035
Revision: 31-Mar-10
RTO 50
50 W Power Resistor, Thick Film Technology, TO-220
Vishay Sfernice
OVERLOADS
The applied voltage must always be lower than the maximum
overload voltage of 450 V.
The values indicated on the graph below are applicable to
resistors in air or mounted onto a heatsink.
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.
ENERGY CURVE
100
100
RATED POWER IN %
ENERGY IN J
10
80
60
1
40
0.1
20
0.01
10
-7
0
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
0
25
50
100
150
200
OVERLOAD DURATION IN s
HEATSINK TEMPERATURE IN °C
MARKING
Model, style, resistance value (in
Ω),
tolerance (in %),
manufacturing date, Vishay Sfernice trademark.
PACKAGING
Tube of 50 units
ORDERING INFORMATION
RTO
MODEL
50
STYLE
F
CONNECTIONS
F: Radial leads
C: Surface mount
100K
RESISTANCE VALUE
± 1%
TOLERANCE
± 1%
± 2%
± 5%
± 10%
XXX
CUSTOM DESIGN
Optional
on request:
Special TCR,
shap, etc.
TU50
e1
PACKAGING LEAD (Pb)-FREE
GLOBAL PART NUMBER INFORMATION
R
T
O
0
5
0
F
R
6
8
0
0
J
T
E
1
GLOBAL
MODEL
RTO
SIZE
050
LEADS
F
= Radial leads
C
= Surface mount
OHMIC VALUE
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
Ω
48701
= 48 700
Ω
10002
= 100 000
Ω
R0100
= 0.01
Ω
R6800
= 0.68
Ω
27000
= 2700
Ω
= 2.7 kΩ
TOLERANCE
F
=1%
G
=2%
J
=5%
K
= 10 %
PACKAGING
T
= Tube
Size 30 and 50:
Tube 50 pieces
Document Number: 50035
Revision: 31-Mar-10
For technical questions, contact:
sfer@vishay.com
www.vishay.com
39
Legal Disclaimer Notice
Vishay
Disclaimer
All product specifications and data are subject to change without notice.
Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf
(collectively, “Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein
or in any other disclosure relating to any product.
Vishay disclaims any and all liability arising out of the use or application of any product described herein or of any
information provided herein to the maximum extent permitted by law. The product specifications do not expand or
otherwise modify Vishay’s terms and conditions of purchase, including but not limited to the warranty expressed
therein, which apply to these products.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this
document or by any conduct of Vishay.
The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications unless
otherwise expressly indicated. Customers using or selling Vishay products not expressly indicated for use in such
applications do so entirely at their own risk and agree to fully indemnify Vishay for any damages arising or resulting
from such use or sale. Please contact authorized Vishay personnel to obtain written terms and conditions regarding
products designed for such applications.
Product names and markings noted herein may be trademarks of their respective owners.
Document Number: 91000
Revision: 18-Jul-08
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1
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