Datasheet

Data Sheet AD8016
Rev. C | Page 19 of 20
EXPERIMENTAL RESULTS
The experimental data suggests that for both packages, and
a PCB as small as 4.7 square inches, reasonable junction
temperatures can be maintained even in the absence of air
flow. The graph in Figure 47 shows junction temperature vs.
airflow for various dimensions of 1 oz. copper PCBs at an
ambient temperature of 24°C in the ARB package. For the
worst-case package, the AD8016 ARB and the worst-case
PCB at 4.7 square inches, the extrapolated junction temperature
for an ambient environment of 85°C would be approximately
132°C with 0 LFM of airflow. If the target maximum junction
temperature of the AD8016 ARB is 125°C, a 4-layer PCB with
1 oz. copper covering the outer layers and measuring 9 square
inches is required with 0 LFM of air flow.
Note that the AD8016 ARE is targeted at xDSL applications
other than full-rate CO ADSL. The AD8016 ARE is targeted
at g.lite and other xDSL applications where reduced power
dissipation can be achieved through a reduction in output
power. Extreme temperatures associated with full-rate ADSL
using the AD8016 ARE should be avoided whenever possible.
Figure 47. Junction Temperature vs. Air Flow
Figure 48. Junction-to-Ambient Thermal Resistance vs. PCB Area
Figure 49. Junction-to-Ambient Thermal Resistance vs. PCB Area
AIR FLOW (LFM)
75
0
JUNCTION TEMPERATURE (°C)
70
65
60
55
50
45
40
20015010050
ARB 4.7 SQ-IN
ARB 7.125 SQ-IN
ARB 9 SQ-IN
ARB 6 SQ-IN
+24°C AMBIENT
01019-047
PCB AREA (SQ-IN)
35
4
θ
JA
(°C/W)
30
25
20
15
10
107
ARB 0 LFM
ARB 50 LFM
ARB 100 LFM
ARB 200 LFM
ARB 150 LFM
01019-048
θ
JA
(°C/W)
40
0
35
30
10456789231
25
20
15
10
50
45
PCB AREA (SQ-IN)
ARE 0 LFM
ARE 200 LFM
ARE 400 LFM
01019-049