PF2470 Series
TO-247 Power Film Resistors
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TO-247 Housing
Rated Power to 140 Watts
Resistances from 0.01 to 51K Ohms
High Stability Film Resistance Elements
Resistance Tolerance to ±0.05%
Low Inductance ( <50nH )
Isolated Back Plate
SPECIFICATIONS
Power Rating
Thermal
Resistance
Type
Resistance Range
3
Min
0.01W
Max
51KW
Heatsink1
Free Air2
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
0.01W
51KW
±1% ( R≥0.10W
)
±5%
Power rating based on 25°C Flange Temperature
Power rating based on 25°C Ambient Temperature
3
Consult Factory for Higher or Lower Values
1
2
Specification
Maximum Current
Temperature Range
Dielectric Strength
Max. Operating Voltage
Insulation Resistance
Value
25A
-55°C to +155°C
2000 VAC
500 V
>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.
11/10
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 Derating Curve
120
100
Power Rating Notes -
The PF2470 Series Foil Resistors must be attached to a suitable
heatsink. The maximum internal resistor temperature is 155°C
(120°C for the PF2201).
To specify an appropriate heatsink use the following formula :
Power ( % )
80
60
40
20
0
R
qH
= T
MAX
- ( P x R
qR
) - T
A
P
-25
0
25
50
75
100
125
150
175
Where:
Ambient 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 )
Mounting Notes -
The PF2470 Series Film Resistors must be attached to a suit-
able 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 mounting
screw to 8 in-lbs ( 0.9 N-m ).
Back plate is isolated from both pins.
Ordering Information
Part Number - Resistance - Tolerance - TCR
Example: PF2472 10 Ohm 1% 50ppm
Riedon Inc.
11/10
300 Cypress Avenue
Alhambra CA 91801
www.riedon.com
(626) 284-9901
(626) 284-1704