LTO 30
www.vishay.com
Vishay Sfernice
30 W Power Resistor Thick Film Technology
FEATURES
• 30 W at 25 °C case temperature heatsink
mounted
• Direct mounting ceramic on heatsink
• Broad resistance range: 0.010 Ω to 550 kΩ
• Non inductive
• TO-220 package: compact and easy to mount
• Material categorization: for definitions of compliance
please see www.vishay.com/doc?99912
LINKS TO ADDITIONAL RESOURCES
3D 3D
3D Models
LTO series are the extension of RTO types. We used the direct ceramic mounting design (no metal tab) of our RCH power
resistors applied to semiconductor packages.
DIMENSIONS in millimeters
3.2
10.4
3.2
16.2
Ø 3.2
1.3
3.5
12.7
0.8
5.08
0.6
1.8
Note
• Tolerances unless stated: ± 0.3 mm
STANDARD ELECTRICAL SPECIFICATIONS
MODEL
SIZE
LTO 30
TO-220
RESISTANCE
RANGE
Ω
RATED POWER LIMITING ELEMENT
TOLERANCE
P25 °C
VOLTAGE UL
±%
W
V
TEMPERATURE
COEFFICIENT
± ppm/°C
CRITICAL
RESISTANCE
Ω
0.01 to < 0.5
30
500
5, 10
250, 700, 900
n/a
0.5 to 550K
30
500
1, 2, 5, 10
150
8.33K
MECHANICAL SPECIFICATIONS
ENVIRONMENTAL SPECIFICATIONS
Mechanical Protection
Temperature Range
Resistive Element
Substrate
Connections
Weight
Mounting Torque
Revision: 08-Dec-2021
Molded
Thick film
Climatic Category
Alumina
Tinned copper
2 g max.
Flammability
-55 °C to +150 °C
55 / 155 / 56
IEC 60695-11-5
Application time: ta = 10 s
Burning duration: tb < 30 s
1 Nm
Document Number: 50049
1
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
LTO 30
www.vishay.com
Vishay Sfernice
TECHNICAL SPECIFICATIONS
Dissipation and Associated
Onto a heatsink
30 W at +25 °C (case temp.)
RTH (j - c): 4.2 °C/W
Free air:
2.25 W at +25 °C
See Performance table
± 150 ppm/°C
1500 VRMS - 1 min
10 mA max.
≥ 104 MΩ
≤ 0.1 μH
Power Rating and Thermal Resistance of the Component
Temperature Coefficient
Standard
Dielectric Strength
MIL STD 202
Insulation Resistance
Inductance
PERFORMANCE
TESTS
CONDITIONS
EN 60115-1
1.5 Pr / 5 s
US < 1.5 UL
EN 60115-1
IEC 60068-2-14 Test Na
5 cycles
-55 °C to +155 °C
EN 60115-1
1000 h Pr at +25 °C
MIL-STD-202
method 103 B cond. D
MIL-STD-202
method 204 cond. D
MIL-STD-202
method 211 cond. A1
100G, MIL-STD-202
method 213 cond. I
Momentary Overload
Rapid Temperature Change
Load Life
Humidity (Steady State)
Vibration
Terminal Strength
Shock
REQUIREMENTS
± (0.5 % + 0.005 Ω)
± (0.5 % + 0.005 Ω)
± (1 % + 0.005 Ω)
± (0.5 % + 0.005 Ω)
± (0.2 % + 0.005 Ω)
± (0.2 % + 0.005 Ω)
± (0.5 % + 0.005 Ω)
SPECIAL FEATURES
Resistance Values
Tolerances
Typical Temperature Coefficient
(-55 °C to +155 °C)
≥ 0.01
≥ 0.015
5 %, 10 %
≥ 0.1
≥ 0.5
1 %, 2 %, 5 %, 10 %
± 900 ppm/°C
± 700 ppm/°C
± 250 ppm/°C
± 150 ppm/°C
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 150 °C. The dissipated power is simply calculated by the following ratio:
(1)
ΔT
P = ------------------------------------------------------------------------------------------R TH (j - c) + R TH (c - h) + R TH (h - a)
P: expressed in W
ΔT: 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.
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 LTO 30 power rating 10 W at ambient temperature +25 °C
Thermal resistance RTH (j - c): 4.2 °C/W
Considering equation (1) we have:
ΔT = 150 °C - 25 °C = 125 °C
ΔT
RTH (j - c) + RTH (c - h) + RTH (h - a) = ------- = 125
-------- = 12.5 °C/W
P
10
RTH (c - h) RTH (h - a) = 12.5 °C/W - 4.2 °C/W = 8.3 °C/W
with a thermal grease RTH (c - h) = 1 °C/W, we need a heatsink with RTH (h - a) = 7.3 °C/W.
Revision: 08-Dec-2021
Document Number: 50049
2
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
LTO 30
www.vishay.com
Vishay Sfernice
OVERLOADS
POWER RATING
In any case the applied voltage must 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.
The temperature of the case 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
125
100
RATED POWER IN %
ENERGY IN JOULES
100
10
1
0.1
75
50
25
0.01
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
0
0
20
OVERLOAD DURATION IN s
40
60
80
100
120
140 150
CASE TEMPERATURE IN °C
POWER CURVE
1 000 000
PACKAGING
Tube of 50 units
POWER IN W
100 000
MARKING
10 000
Model, style, resistance value (in Ω), tolerance (in %),
manufacturing date, Vishay Sfernice trademark.
1000
100
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
OVERLOAD DURATION IN s
Revision: 08-Dec-2021
Document Number: 50049
3
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
LTO 30
www.vishay.com
Vishay Sfernice
ORDERING INFORMATION
LTO
30
F
2.7 kΩ
±1%
xxx
TU50
e3
MODEL
STYLE
CONNECTIONS
RESISTANCE VALUE
TOLERANCE
CUSTOM DESIGN
optional
on request:
special TCR,
shape etc.
PACKAGING
LEAD (Pb)-FREE
±1%
±2%
±5%
± 10 %
GLOBAL PART NUMBER INFORMATION
L
T
O
0
3
0
F
2
7
0
0
0
J
T
E
3
GLOBAL
MODEL
SIZE
LEADS
OHMIC VALUE
TOLERANCE
PACKAGING
LEAD (Pb)-FREE
LTO
030
F = radial leads
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
R4700 = 0.47 Ω
27000 = 2700 Ω = 2.7 kΩ
F=1%
G=2%
J=5%
K = 10 %
T = tube
E3 = pure tin
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
Revision: 08-Dec-2021
Document Number: 50049
4
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
Legal Disclaimer Notice
www.vishay.com
Vishay
Disclaimer
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Revision: 01-Jan-2023
1
Document Number: 91000