P R E L I M I N A R Y
Table 16 shows typical maximum ambient temperatures in degrees Centigrade for a PQFP package used on a 4-
layer to 6-layer board. The typical ambient temperatures are based on a 100-degree Centigrade maximum case
temperature. Figure 17 graphically illustrates the typical temperatures in Table 16.
Table 16. Typical Ambient Temperatures (°C) for PQFP with a 4-Layer to 6-Layer Board
Linear Feet per Minute Airflow
Microcontroller
Speed
Typical Power
(Watts)
0 fpm
78.8
82.5
86.7
89.4
200 fpm
81.1
400 fpm
83.5
600 fpm
85.8
40 MHz
33 MHz
25 MHz
20 MHz
1.2
1.0
0.7
0.6
84.4
86.4
88.3
88.2
89.7
91.2
90.6
91.7
92.9
95
90
85
80
■
■
◆
■
◆
◆
■
◆
✶
✶
●
●
✶
●
✶
●
Legend:
75
70
● 40 MHz
✵ 33 MHz
◆ 25 Mhz
■ 20 MHz
0 fpm
200 fpm
600 fpm
400 fpm
Airflow (Linear Feet Per Minute)
Figure 17. Typical Ambient Temperatures for PQFP with a 4-Layer to 6-Layer Board
Am186ED/EDLV Microcontrollers
55
AMD [ AMD ]
