Table 1. commercial heatsink selection guide – Fairchild DUAL TRACKING VOLTAGE REGULATORS RC4194 User Manual

Page 10

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PRODUCT SPECIFICATION

RC4194

10

Table 1. Commercial Heatsink Selection Guide

No attempt has been made to provide a complete list of all heatsink manufacturers. This list is only representative.

Staver Co., Inc.: 41-51 N Saxon Ave., Bay Shore, NY 11706
IERC: 135 W Magnolia Blvd., Burbank, CA 91502
Thermalloy: P.O. Box 34829, 2021 W Valley View Ln., Dallas, TX
Wakefield Engin Ind: Wakefield, MA 01880
* All values are typical as given by manufacturer or as determined from characteristic curves supplied by manufacturer.

q

S-A

1

(

°

C/W)

Manufacturer/Series or Part Number

TO-66 Package

0.31 – 1.0

Thermalloy — 6441, 6443, 6450, 6470, 6560, 6590, 6660, 6690

1.0 – 3.0

Wakefield — 641

Thermalloy — 6123, 6135, 6169, 6306, 6401, 6403, 6421, 6423, 6427, 6442, 6463, 6500

3.0 – 5.0

Wakefield — 621, 623

Thermalloy — 6606, 6129, 6141, 6303

IERC — HP

Staver — V3-3-2

5.0 – 7.0

Wakefield — 690

Thermalloy — 6002, 6003, 6004, 6005, 6052, 6053, 6054, 6176, 6301

IERC — LB

Staver— V3-5-2

7.0 – 10.0

Wakefield — 672

Thermalloy — 6001, 6016, 6051, 6105, 6601

IERC — LA, uP

Staver — V1-3, V1-5, V3-3, V3-5, V3-7

10.0 – 25.0

Thermalloy — 6-13, 6014, 6015, 6103, 6104, 6105, 6117

Dual In-line Package

20

Thermalloy — 6007

30

Thermalloy — 6010

32

Thermalloy — 6011

34

Thermalloy — 6012

45

IERC — LI

60

Wakefield — 650, 651

In the above example, let’s say that the user’s load current is
200 mA and he wants to calculate the combined

q

C-S

and

q

S-A

he needs:

Given: I

O

= 200 mA,

= 11.75

°C/W

Given

q

J-C

= 7.15

°C/W for the 4194 in the K package,

q

C-S

+

q

S-A

= 11.75

°C/W – 7.15°C/W

= 4.6

°C/W

When using heatsink compound with a metal-to-metal
interface, a typical

q

C-S

= 0.5

°C/W for the K package.

The remaining

q

S-A

of approximately 4

°C/W is a large

enough thermal resistance to be easily provided by a number
of heatsinks currently available. Table 1 is a brief selection
guide to heatsink manufacturers.

q

J

A

T

J

T

A

V

IN

V

OUT

(

) I

O

V

IN

I

Q

´

+

´

---------------------------------------------------------------------------

=

50

°C 125°C

10V

200mA

´

40

+

3.25

10

3

´

´

----------------------------------------------------------------------------------

=

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