HDSP-2531 Avago Technologies US Inc., HDSP-2531 Datasheet - Page 14

• Manufacturer Part Number: HDSP-2531
• Description: LED DISPLAY 5X7 8CHAR 5MM YLW
• Manufacturer: Avago Technologies US Inc.
• Series: HDSP-253xr

Specifications of HDSP-2531

• Display Type: Alphanumeric
• Common Pin: *
• Package / Case: 28-DIP
• Color: Yellow
• Size / Dimension: 1.69" x .45" (42.9mm x 11.4mm)
• 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: Yellow
• Wavelength: 585 nm
• Operating Voltage: 5 V
• Operating Current: 370 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Luminous Intensity: 7.5 ucd
• Viewing Area (w X H): 40.06 mm x 4.57 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 516-1168-5

Table 3 shows the calculated maximum allowable ambient
temperature for several different sets of operating condi-
tions. The worst case alphanumeric characters (#,@,B)
have 20 pixels. Displaying eight 20-pixel characters will
not occur in normal operation. Thus, using eight 20-pixel
characters to calculate power dissipation will over estimate
the power and the IC junction temperature. The average
number of pixels per character, supply voltage, brightness
level, and number of characters are needed to calculate
the power dissipated by the IC. The ambient temperature,
power dissipated by the IC, and the thermal resistance
are then used to calculate IC junction temperature. The
typical alphanumeric character is 15 pixels. For conditions
not listed in Table 3, you can calculate the power dissipat-
ed by the IC and use Figure 10 to determine the maximum
ambient temperature.
Table 3. Maximum Allowable Ambient Temperature for Various Operating Conditions
AlGaAs Red
Character
# (20 dots)
# (20 dots)
# (20 dots)
# (20 dots)
# (20 dots)
# (20 dots)
# (20 dots)
# (20 dots)
V (12 dots)
Table 4. Maximum Allowable Ambient Temperature for Various Operating Conditions (cont’ d .)
All Colors Except AlGaAs Red
Character
# (20 dots)
# (20 dots)
# (20 dots)
# (20 dots)
# (20 dots)
# (20 dots)
V (12 dots)
The actual IC temperature is easy to measure. Pin 17 is thermally and electrically connected to the IC substrate. The thermal resistance from pin 17 to
the IC is 16°C/W. The procedure to measure the IC junction temperature is as follows:
1. Measure V
2. Measure the temperature of pin 17 after 45 minutes. Use an electrically isolated thermal couple probe.
3. T
14
J
(IC) = T
pin
DD
+ V
and I
DD
x I
DD
Number of
Characters
8
8
8
7
6
8
8
8
8
Number of
Characters
8
8
8
7
6
8
8
DD
for the display. Measure V
x 16°C/W.
Brightness
Level
100%
100%
100%
100%
100%
80%
80%
53%
100%
Brightness
Level
100%
100%
100%
100%
100%
80%
100%
DD
between pins 15 and 16. Measure the current entering pin 15.
V
V
5.5
5.25
5.0
5.5
5.5
5.5
5.25
5.5
5.5
V
V
5.5
5.25
5.0
5.5
5.5
5.5
5.5
DD
DD
Figure 10. Maximum allowable power dissipation vs. ambient temperature.
T
J
MAX = 150°C or 120°C.
I
mA
408
387
366
357
306
327
310
216
228
I
mA
373
354
335
326
280
298
207
DD
DD
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
1.5
50
ALL OTHER COLORS
55 60
T
A
AlGaAs
– AMBIENT TEMPERATURE – C
65
P
W
2.2
2.0
1.8
2.0
1.7
1.8
1.6
1.2
1.3
P
W
2.0
1.9
1.67
1.8
1.5
1.6
1.1
70
D
D
Rθ
75
J-A
= 39C/W
80
85
Rq
°C/W
39
39
39
39
39
39
39
39
39
Rq
°C/W
39
39
39
39
39
39
39
J-A
J-A
90
T
°C
64
72
80
72
84
80
85
85
85
T
°C
72
77
85
80
85
85
85
A
A
MAX
MAX