Datasheet
13
Figure 8. Cascaded ICs.
CE
IC2
BITS 160-319
CHARACTERS 4-7
RS
BL
SEL
OSC
CLK
D
OUT
D
IN
IC1
BITS 0-159
CHARACTERS 0-3
D
IN
RS
BL
SEL
OSC
CLK
D
OUT
CE
RESET
RESET
RS
BL
SEL
OSC
CLK
D
OUT
CE
RESET
D
IN
Figure 9. Maximum power dissipation per IC versus ambient temperature.
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 Rθ
JA
is 100°C/ W. This value is typical for
a display mounted in a socket and covered with a plastic
lter. The socket is soldered to a 0.062 inch thick PCB with
0.020-inch wide, Figure 9. Maximum power dissipation
per IC versus ambient temperature. one ounce copper
traces. P
D
can 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 tem-
peratures may require the power per IC to be reduced.
The power consumption can be reduced by changing the
N, I
PIXEL
, Osc cyc or V
LED
. Changing V
LOGIC
has very little
impact on the power consumption.
0
25
0.7
0.6
0.5
0.4
0.3
0.2
0.1
60555045403530
0.8
0.9
1.0
1.1
1.2
8580757065 90
1.3
P
D
MAX – MAXIMUM POWER
DISSIPATION PER IC – W
T
A
– AMBIENT TEMPERATURE – °C
Rθ
J-A
= 100°C/W