CMF5038R300FHEB Vishay, CMF5038R300FHEB Datasheet - Page 3
![RES 38.3 OHM 1% 50PPM 1/4W](/photos/13/24/132422/cmf50_sml.jpg)
CMF5038R300FHEB
Manufacturer Part Number
CMF5038R300FHEB
Description
RES 38.3 OHM 1% 50PPM 1/4W
Manufacturer
Vishay
Series
CMFr
Datasheet
1.CMF5524R900FHEB.pdf
(5 pages)
Specifications of CMF5038R300FHEB
Resistance (ohms)
38.3
Power (watts)
0.25W, 1/4W
Composition
Metal Film
Features
Flame Retardant Coating
Temperature Coefficient
±50ppm/°C
Tolerance
±1%
Size / Dimension
0.065" Dia x 0.187" L (1.65mm x 4.75mm)
Lead Style
Through Hole
Package / Case
Axial
Resistance In Ohms
38.3
Case
Axial
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Height
-
Other names
CMF38.3QFTR
CMF Industrial
Vishay Dale
www.vishay.com
20
DERATING
LOAD LIFE SHIFT DUE TO POWER AND DERATING (AT 70 °C AND AT + 125 °C)
The power rating for the CMF parts is tied to the derating temperature, the heat rise of the parts, and the ΔR for the load life performance.
When the tables/graphs below are used together they show that when the parts are run at their higher power ratings, the parts will run
hotter, which has the potential of causing the resistance of the parts to shift more over the life of the part.
CMF resistors have an operating temperature range of - 55 °C to
+ 175 °C. They must be derated at high ambient temperatures
according to the derating curve.
Example:
When a CMF55 part is run at 1/8 W in a 70 °C ambient environment, the resistor will generate enough heat that the surface temperature of
the part will reach about 19 °C over the ambient temperature, and over the life of the part this could cause the resistance value to shift up to
± 0.15 %.
If the same resistor was instead run at 1/4 W in a 70 °C environment, the element will heat up to about 30 °C over ambient, and over the life
of the part the resistance value could shift roughly ± 0.5 %.
And if the resistor was run at it maximum power rating of 1/2 W in a 70 °C environment, it will heat up to about 58 °C over ambient, and you
could see the resistance value shift roughly ± 1 % over the life of the part.
MATERIAL SPECIFICATIONS
Element:
Core:
LOAD LIFE SHIFT VS. POWER RATING
LOAD LIFE
MODEL
CMF50
CMF55, CMF07
CMF60, CMF20
CMF65
CMF70
120
100
- 55 - 50 - 25
80
60
40
20
0
0
25
Vacuum-deposited nickel-chrome alloy
Fire-cleaned high purity ceramic
1/20 W and 1/10 W
1/10 W and 1/8 W
50
1/8 W and 1/4 W
1/4 W and 1/2 W
1/4 W and 1/2 W
± 0.15 %
70 75 100
AMBIENT TEMPERATURE IN °C
Metal Film Resistors, Industrial, Precision
For technical questions, contact:
POWER RATING AT + 70 °C
125
150 165 175
± 0.5 %
1/8 W
1/4 W
1/2 W
3/4 W
3/4 W
MAXIMUM ΔR (TYPICAL TEST LOTS)
200
THERMAL RESISTANCE
Coating:
Solderability:
3/4 W and 1 W
120
100
ff2aresistors@vishay.com
80
60
40
20
0
± 1.0 %
0
1/4 W
1/2 W
1 W
1 W
0.125
0.25
Flame retardant epoxy, formulated for superior
Continuous satisfactory coverage when tested
± 0.15 %
1/20 W
1/10 W
0.375
1/8 W
1/4 W
1/4 W
POWER RATING AT + 125 °C
in accordance with MIL-R-10509
0.5
moisture protection
0.625
± 0.5 %
1/10 W
1/8 W
1/4 W
1/2 W
1/2 W
Document Number: 31018
0.75
APPLIED POWER IN W
CMF50
Revision: 20-Jul-10
0.875
± 1.0 %
1/8 W
1/4 W
1/2 W
3/4 W
3/4 W
CMF55,
CMF07
CMF65,
CMF70
1
CMF60,
CMF20
1.125