RHA

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Vishay Dale

Revision: 22-Feb-2022

3

Document Number: 30406

For technical questions, contact: ww2aresistors@vishay.com

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AMBIENT TEMPERATURE DERATING

Derating is required for ambient temperatures above 25 °C, see the following graph.

Curves A, B, C apply to operation of unmounted resistors. Curve D applies to all types when mounted to specified heat sink.

A = RHA005 and RHA010 size resistor, unmounted

B = RHA025 size resistor, unmounted

C = RHA050 size resistor, unmounted

D = All types mounted to recommended aluminum heat sink

REDUCED HEAT SINK DERATING

Derating is also required when recommended heat sink area is reduced.

A = RHA005 and RHA010 size resistor

B = RHA025 size resistor

C = RHA050 size resistor

AMBIENT TEMPERATURE IN °C

25

120

A

C

D

B

0

20

40

60

80

100

-55 -50

0

50

150

250

0

100

80

60

40

20

0

100

90

80

70

60

50

40

30

20

10

% OF RECOMMENDED HEAT SINK AREA

C

B

A