HCMS-2905 Avago Technologies US Inc., HCMS-2905 Datasheet - Page 14
HCMS-2905
Manufacturer Part Number
HCMS-2905
Description
LED DISPL 5X7 4CHAR 3.8MM ALGAAS
Manufacturer
Avago Technologies US Inc.
Series
HCMS-29xxr
Datasheet
1.HCMS-2903.pdf
(16 pages)
Specifications of HCMS-2905
Millicandela Rating
*
Internal Connection
*
Size / Dimension
0.70" L x 0.40" W x 0.20" H (17.8mm x 10.2mm x 5.1mm)
Color
Red
Configuration
*
Voltage - Forward (vf) Typ
*
Package / Case
12-DIP
Display Type
Alphanumeric
Number Of Digits/alpha
4
Digit/alpha Size
0.15" (3.8mm)
Character Format
Dot Matrix
Character Size
3.81mm
Led Color
Red
Luminous Intensity
230µcd
No. Of Digits / Alpha
4
Display Area Width
17.78mm
Display Area Height
10.16mm
Emitting Color
Red
Number Of Digits
4
Digit Size (in)
.15in
Viewing Area Height (mm)
3.71mm
Viewing Area Length (mm)
2.11mm
Package Type
DIP
Operating Supply Voltage (min)
3V
Operating Supply Voltage (typ)
5V
Operating Supply Voltage (max)
5.5V
Operating Temperature Classification
Industrial
Operating Temp Range
-40C to 85C
Mounting
Through Hole
Pin Count
12
Total Thickness (mm)
5.08mm
Opto Display Type
Panel
Pattern Type
Dot Matrix
Illumination Color
Red
Wavelength
645 nm
Operating Voltage
- 0.3 V to 5.5 V
Maximum Operating Temperature
+ 85 C
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Common Pin
-
Lead Free Status / Rohs Status
Compliant
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 below.
A typical value for Rq
for a display mounted in a socket and covered with a
plastic filter. The socket is soldered to a .062 in. thick PCB
with .020 inch wide, one ounce copper traces.
P
Figure 4 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
either the N, I
very little impact on the power consumption.
Appendix B. Electrical Considerations
14
D
can be calculated as Equation 2 below.
Equation 1:
T
Where:
Equation 2:
P
Where:
Duty Factor = 1/8 * Osccyc/64
Equation 3:
I
Where:
Equation 4:
I
(see Variable Definitions above)
PEAK
LED
J
D
MAX = T
= (N * I
(AVG) = N * I
= M * 20 * I
Osc cyc = number of ON oscillator cycles per row
T
I
I
V
PIXEL
I
PEAK
J
I
LOGIC
LOGIC
MAX = maximum IC junction temperature
Rq
PIXEL
20 = maximum number of LEDs on per IC
PIXEL
M = number of ICs in the system
A
PIXEL
P
P
T
+ P
JA
N = number of pixels on (maximum 4 char * 5 * 7 = 140)
= maximum instantaneous peak current for the display
= peak current for one LED
A
D
D
= ambient temperature surrounding the display
= thermal resistance from the IC junction to ambient
= power dissipated by the IC
= total power dissipation
= peak pixel current.
= IC logic current
= logic supply voltage
, Osc cyc or V
* Duty Factor * V
D
* Rq
PIXEL
PIXEL
JA
is 100°C/W. This value is typical
* 1/8 * (oscillator cycles)/64
JA
LED
. Changing V
LED
) + I
LOGIC
* V
LOGIC
LOGIC
has
Figure 4.
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
50
55
R
60
θ
J-A
65
= 100°C/W
70
75
80
85
90