NPS
2-T126
Power SMD Resistors
SPECIFICATIONS
(continued)
Derating
120
100
Power (% from
nominal power)
Power Rating Notes -
80
60
40
20
0
0
25 40 55 70 85 100 115 130 145 155 175
Temperature of the backplate (°C)
The NPS Series Resistors must be attached to a suitable heat-
sink. The maximum internal resistor temperature is 175°C.
To specify an appropriate heatsink use the following formula :
R
qH
= T
MAX
- ( P x R
qR
) - T
A
P
Where:
R
qH
= Thermal Resistance of Heatsink ( K/W )
R
qR
= Thermal Resistance of Resistor ( K/W )
T
MAX
= Maximum Temperature of Resistor
T
A
= Ambient Temperature of Heatsink ( °C )
P = Power Through Resistor ( W )
Dimensions
Dimension
A
B
C
D
E
F
G
H
I
J
K
L
M
N
mm
8.26
8.13
6.35
4.31
1.35
5.08
0.76
2.79
0.8
9.55
10.92
12.32
0.6
1.47
tol.
(±mm)
0.2
0.2
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.2
0.2
0.2
0.1
0.1
inches
0.33
0.32
0.25
0.17
0.05
0.20
0.03
0.11
0.03
0.38
0.43
0.49
0.02
0.06
tol.
(±inches)
0.008
0.008
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.008
0.008
0.008
0.004
0.004
Dimension
A
B
C
D
E
F
mm
8.51
7.87
14.1
5.08
1.65
3.81
inches
0.335
0.310
0.555
0.200
0.065
0.150
Riedon Inc.
300 Cypress Avenue
Alhambra CA 91801
(626) 284-9901
(626) 284-1704
Page 84
rev. 03/2006A
RIEDON [ RIEDON POWERTRON ]
