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
–
´
´
----------------------------------------------------------------------------------
=
