LTO 30
www.vishay.com
Vishay Sfernice
Revision: 16-Nov-17
1
Document Number: 50049
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
30 W Power Resistor Thick Film Technology
DESIGN SUPPORT TOOLS
FEATURES
• 30 W at 25 °C case temperature heatsink
mounted
• Direct mounting ceramic on heatsink
• Broad resistance range: 0.010 to 550 k
• Non inductive
• TO-220 package: compact and easy to mount
• Material categorization: for definitions of compliance
please see www.vishay.com/doc?99912
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.
Note
• Tolerances unless stated: ± 0.3 mm
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Available
Models
DIMENSIONS in millimeters
STANDARD ELECTRICAL SPECIFICATIONS
MODEL SIZE
RESISTANCE
RANGE
RATED POWER
P
25 °C
W
LIMITING ELEMENT
VOLTAGE U
L
V
TOLERANCE
± %
TEMPERATURE
COEFFICIENT
± ppm/°C
CRITICAL
RESISTANCE
LTO 30 TO-220 0.010 to 550K 30 500 1, 2, 5, 10 150, 250, 700, 900 8.33K
3.2
16.2
10.4
1.8
5.08
0.6
3.5
1.3
0.8
12.7
3.2
Ø 3.2
MECHANICAL SPECIFICATIONS
Mechanical Protection Molded
Resistive Element Thick film
Substrate Alumina
Connections Tinned copper
Weight 2 g max.
Mounting Torqure 1 Nm
ENVIRONMENTAL SPECIFICATIONS
Temperature Range -55 °C to +150 °C
Climatic Category 55 / 155 / 56
Flammability
IEC 60695-11-5
2 applications 30 s
separated by 60 s
TECHNICAL SPECIFICATIONS
Dissipation and Associated Onto a heatsink
Power Rating and
Thermal Resistance
of the Component
30 W at +25 °C (case temp.)
R
TH (j - c)
: 4.2 °C/W
Free air:
2.25 W at +25 °C
Temperature Coefficient See Performance table
Standard ± 150 ppm/°C
Dielectric Strength
MIL STD 202
1500 V
RMS
- 1 min
10 mA max.
Insulation Resistance 10
4
M
Inductance 0.1 μH
LTO 30
www.vishay.com
Vishay Sfernice
Revision: 16-Nov-17
2
Document Number: 50049
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 150 °C. The dissipated power is simply calculated by the following ratio:
P: Expressed in W
T: Difference between maximum working temperature and room
temperature
R
TH (j - c)
: Thermal resistance value measured between resistive layer
and outer side of the resistor. It is the thermal resistance of the
component.
R
TH (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.
R
TH (h - a)
: Thermal resistance of the heatsink.
Example:
R
TH (c - a)
for LTO 30 power rating 10 W at ambient temperature +25 °C
Thermal resistance R
TH (j - c)
: 4.2 °C/W
Considering equation
(1)
we have:
T = 150 °C - 25 °C = 125 °C
R
TH (j - c)
+ R
TH (c - h)
+ R
TH (h - a)
= = = 12.5 °C/W
R
TH (c - h)
R
TH (h - a)
= 12.5 °C/W - 4.2 °C/W = 8.3 °C/W
with a thermal grease R
TH (c - h)
= 1 °C/W, we need a heatsink with R
TH (h - a)
= 7.3 °C/W.
PERFORMANCE
TESTS CONDITIONS REQUIREMENTS
Momentary Overload
EN 60115-1
1.5 Pr / 5 s
U
S
< 1.5 U
L
± (0.5 % + 0.005 )
Rapid Temperature Change
EN 60115-1
IEC 60068-2-14 Test Na
5 cycles
-55 °C to +155 °C
± (0.5 % + 0.005 )
Load Life
EN 60115-1
1000 h Pr at +25 °C
± (1 % + 0.005 ���)
Humidity (Steady State)
MIL-STD-202
method 103 B cond. D
± (0.5 % + 0.005 )
Vibration
MIL-STD-202
method 204 cond. D
± (0.2 % + 0.005 )
Terminal Strength
MIL-STD-202
method 211 cond. A1
± (0.2 % + 0.005 )
Shock
100G, MIL-STD-202
method 213 cond. I
± (0.5 % + 0.005 )
SPECIAL FEATURES
Resistance Values 0.010 0.015 0.1 0.5
Tolerances ± 1 % at ± 10 %
Typical Temperature Coefficient
(-55 ° to +155 °C)
± 900 ppm/°C ± 700 ppm/°C ± 250 ppm/°C ± 150 ppm/°C
P
T
R
TH (j - c)
R
TH (c - h)
R
TH (h - a)
++
----------------------- --------------------------- -------------------------- ---------------
1
=
T
P
-------
125
10
--------