PF2470 Series
TO-247 Power Film Resistors
•
•
•
•
•
•
•
TO-247 Housing
Rated Power to 140 Watts
Resistances from 0.02 to 51K Ohms
High Stability Film Resistance Elements
Resistance Tolerance to ±1%
Low Inductance ( <50nH )
Isolated Back Plate
SPECIFICATIONS
Power Rating
Thermal
Resistance
Type
Heatsink1
Free Air2
Resistance Range
3
Min
0.02W
Max
51KW
Tolerances
Temperature
Coefficients
±50ppm/°C ( R≥10W
)
±100ppm/°C ( 0.1W ≤ R <
10W )
±250ppm/°C ( R < 0.1W
)
±50ppm/°C ( R≥10W
)
±100ppm/°C ( 0.1W ≤ R <
10W )
±250ppm/°C ( R < 0.1W
)
PF2473
140W
5W
0.9°C/W
±1% ( R≥0.10W
)
±5%
PF2472
100W
3W
1.3°C/W
0.02W
51KW
±1% ( R≥0.10W
)
±5%
1
2
Power rating based on 25°C Flange Temperature
Power rating based on 25°C Ambient Temperature
3
Consult Factory for Higher or Lower Values
Specification
Temperature Range
Dielectric Strength
Max. Operating Voltage
Insulation Resistance
Value
-55°C to +155°C
2500 VAC
700 V or √P*R, whichever is less
>1000 Meg-Ohm
Environmental Performance
Load Life
Humidity Resistance
Temperature Cycle
Solder Heat
Vibration
DR
±1% + 0.05W
±1% + 0.05W
±0.25% + 0.05W
±0.1% + 0.05W
±0.25% + 0.05W
Test Conditions
25°C, 90 min ON, 30 min OFF, 1000 hr
40°C, 90-95% RH, DC 0.1W, 1000 hr
-55°C for 30 min, +155°C for 30 min, 1000 hr
+350°C, 3s
IEC60068-2-6
Riedon Inc.
08/14
300 Cypress Avenue
Alhambra CA 91801
www.riedon.com
(626) 284-9901
(626) 284-1704
PF2470 Series
TO-247 Power Film Resistors
SPECIFICATIONS
(continued)
Power Rating Notes -
The PF2470 Series Thin Film Resistors must be attached to a suit-
able heatsink. The maximum internal resistor temperature is 155°C.
To specify an appropriate heatsink use the following formula :
Power Derating Curve
120
100
Power ( % )
80
60
40
20
0
R
H
H
=
Where:
-25
0
25
50
75
100
125
150
175
T
MAX
- (
P
*
R
H
R
) -
T
A
P
Backplate Temperature (°C)
R
qH
= Thermal Resistance of Heatsink ( °C/W )
R
qR
= Thermal Resistance of Resistor ( °C/W )
T
MAX
= Maximum Temperature of Resistor
T
A
= Ambient Temperature of Heatsink ( °C )
P = Power Through Resistor ( W )
0.630 [16.0]
0.189 [4.8]
0.201 [5.1]
0.787 [20.0]
ø0.142 [ø3.6]
0.142 [3.6]
0.571 [14.5]
ø0.032 [0.8]
0.429 [10.9]
Mounting Notes -
The PF2470 Series Thin Film Resistors must be attached to
a suitable heatsink. Mount resistor using thermal grease to a
clean, flat surface. Use a compression washer to provide 150 to
300 pounds ( 665 to 1330N ) of mounting force. Torque mount-
ing screw to 8 in-lbs ( 0.9 N-m ).
Back plate is isolated from both pins.
Ordering Information
Part Description: Part Type - Resistance - Tolerance
Example: PF2472 10 Ohm 1%
Riedon Inc.
08/14
300 Cypress Avenue
Alhambra CA 91801
www.riedon.com
(626) 284-9901
(626) 284-1704