P R E L I M I N A R Y
Table 13 shows typical maximum ambient temperatures in degrees Centigrade for a PQFP package used on a 2-
layer board. The typical ambient temperatures are based on a 100-degree Centigrade maximum case temperature.
Figure 15 graphically illustrates the typical temperatures in Table 13.
Table 13. Typical Ambient Temperatures for PQFP with a 2-Layer Board
Linear Feet per Minute Airflow
Microcontroller
Speed
Typical Power
(Watts)
0 fpm
52.918
59.3077
69.1725
75.338
200 fpm
60.352
65.7328
74.04
400 fpm
65.308
70.0162
77.285
81.828
600 fpm
67.786
40 MHz
33 MHz
25 MHz
20 MHz
1.239
1.07085
0.81125
0.649
72.1579
78.9075
83.126
79.232
90
80
70
60
■
■
■
◆
◆
◆
■
◆
✶
●
✶
●
✶
●
✶
●
50
40
Legend:
● 40 MHz
✵ 33 MHz
◆ 25 Mhz
■ 20 MHz
0 fpm
200 fpm
600 fpm
400 fpm
Airflow (Linear Feet Per Minute)
Figure 15. Typical Ambient Temperatures for PQFP with a 2-Layer Board
Am186/188ES and Am186/188ESLV Microcontrollers
57
AMD [ AMD ]
