HCMS-39X2 HP [Agilent(Hewlett-Packard)], HCMS-39X2 Datasheet - Page 18

• Manufacturer Part Number: HCMS-39X2
• Description: 3.3 V High Performance CMOS 5x7 AlphaNumeric Displays
• Manufacturer: HP [Agilent(Hewlett-Packard)]

Appendix A. Thermal
Considerations
The display IC has a maximum
junction temperature of 150 C.
The IC junction temperature can
be calculated with Equation 1 in
Table 3.
A typical value for R
W. This value is typical for a
display mounted in a socket and
covered with a plastic filter. The
socket is soldered to a .062 inch
thick PCB with .020-inch wide,
Figure 9. Maximum power dissipation per IC versus ambient temperature.
18
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
25
30
T
35
A
– AMBIENT TEMPERATURE – °C
40
45
JA
50
is 100 C/
55
R
60
J-A
65
= 100°C/W
70
75
one ounce copper traces. P
be calculated as Equation 2 in
Table 3.
Figure 9 shows how to derate the
power of one IC versus ambient
temperature. Operation at high
ambient temperatures may
require the power per IC to be
reduced. The power consumption
can be reduced by changing the
N, I
Changing V
impact on the power
consumption.
80
85
PIXEL
90
, Osc cyc or V
LOGIC
has very little
LED
.
D
can