HCMS-3977 Avago Technologies US Inc., HCMS-3977 Datasheet - Page 18

• Manufacturer Part Number: HCMS-3977
• Description: LED DISPLAY 5X7 8CHAR 5MM GRN
• Manufacturer: Avago Technologies US Inc.
• Series: HCMS-39xxr

Specifications of HCMS-3977

• Display Type: Alphanumeric
• Millicandela Rating: *
• Internal Connection: *
• Size / Dimension: *
• Color: Green
• Configuration: *
• Voltage - Forward (vf) Typ: *
• Package / Case: 26-DIP
• Number Of Digits/alpha: 8
• Digit/alpha Size: 0.20" (5mm)
• Number Of Digits: 8
• Character Size: 2.54 mm x 4.57 mm
• Illumination Color: Green
• Wavelength: 574 nm
• Operating Voltage: 3.3 V
• Operating Current: 10 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Luminous Intensity: 1000 ucd
• Power Consumption: 1.532 W
• Viewing Area (w X H): 40.06 mm x 4.57 mm
• Common Pin: None
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

18
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.
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
JA
45
is 100 C/
50
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
PIXEL
85
90
, Osc cyc or V
LOGIC
has very little
LED
.
D
can