FPR FNR
2-T227 4-T227
Foil Power Resistors
SPECIFICATIONS
(continued)
Temperature Coefficient
4000
250
2000
+15ppm/K
table A
200
0
-15ppm/K
Limit 2 (3σ)
Nominal ∆R/R
Limit 1 (3σ)
-2000
-4000
TCR - Shift (ppm/K)
∆R/R (ppm)
150
100
-6000
50
-8000
-40
-20
0
20
40
60
80
100
120
140
0
2
Temperature (°C)
Resistance Value (mOhm)
5
10
20
50
100
200
Derating and Stability
Power Rating Notes -
120
100
Power ( % from
nominal power)
0.5%
0.2%
0.1%
The FPR/FNR Series Foil Resistors must be attached to a suit-
able heatsink. The maximum internal resistor temperature is
130°C for a 0.5% stability part.
To specify an appropriate heatsink use the following formula :
80
60
40
20
0
25
R
θH
= T
MAX
- ( P x R
θR
) - T
A
P
Where: R
θ
H
= Thermal Resistance of Heatsink ( K/W )
50
85
100
115
130
Tem perature of the backplate (°C)
R
θ
R
= 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 and Attachment Variations
Dimension
A
B
C
D
E
F
G
H
I
J
K
L
M
N
mm
26
38
12.7
4
30
15
4.1
10
8
4
2
0.8
M4
10
11.9
0.2
0.2
tol.
(±mm)
0.5
0.5
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.1
inches
1.02
1.50
0.50
0.16
1.18
0.59
0.16
0.39
0.31
0.16
0.08
0.03
M4
0.39
0.47
0.008
0.008
tol.
(±inches)
0.020
0.020
0.008
0.008
0.008
0.008
0.008
0.008
0.008
0.008
0.008
0.004
FPR/FNR 2-T227
Riedon Inc.
FPR/FNR 4-T227
Alhambra CA 91801
O
300 Cypress Avenue
(626) 284-9901
(626) 284-1704
Page 44
rev. 03/2006A