AS1100PE-Z AMSCO [austriamicrosystems AG], AS1100PE-Z Datasheet - Page 10

• Manufacturer Part Number: AS1100PE-Z
• Description: Serially Interfaced, 8-Digit LED Driver
• Manufacturer: AMSCO [austriamicrosystems AG]

Data Sheet AS1100
Computing Power Dissipation
The upper limit for power dissipation (PD) for the AS1100 is determined from the following equation:
where:
Dissipation Example:
PD = 5.25V(0.5mA) + (5.25V - 1.8V)(31/32 x 40mA x 8) = 1.07W
Thus, for a PDIP package
where T
The T
Package Information
Revision 1.32, Oct. 2004
Figure 4: SOIC-24 package dimensions
PD = (VDD x 0.5mA) + (VDD - V
I
SEG
T
J,MAX
Dim Min
A1 0.004 0.012 0.10
A
A
B
C
D
E
H
= 40mA, N = 8, DUTY = 31/32, V
e
L
limit for SO Packages in the dissipation example above is +59.0°C.
A
= T
VDD = supply voltage
DUTY = duty cycle set by intensity register
N = number of segments driven (worst case is 8)
V
I
= +69.7°C.
SEG
0.093 0.104 2.35
0.014 0.019 0.35
0.009 0.013 0.23
0.598 0.614 15.20
0.291 0.299 7.40
0.394 0.419 10.00
0.016 0.050 0.40
LED
A
Inches
0.050
= segment current set by R
+ PD x
= LED forward voltage
Max
J A
Min
Millimeters
= 150°C = T
JA
1.27
= +75°C/W (from Table 13), the maximum allowed ambient temperature T
15.60
10.65
Max
2.65
0.30
0.49
0.32
7.60
1.27
LED
)(DUTY x I
A
L ED
+1.07W x 75°C/W.
SET
= 1.8V at 40mA, VDD = 5.25V
SEG
x N)
A
is given by:
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