P R E L I M I N A R Y
Table 12 shows typical maximum ambient temperatures in degrees Centigrade for a TQFP package used with a
2-layer board. The typical ambient temperatures are based on a 100-degree Centigrade maximum case tempera-
ture. Figure 18 illustrates the typical temperatures in Table 12.
Table 12. Typical Ambient Temperatures for TQFP with 2-Layer Board
Linear Feet per Minute Airflow
Microcontroller
Speed
Typical Power
(Watts)
0 fpm
43.006
50.7409
62.6825
70.146
200 fpm
55.396
61.4494
70.795
76.636
400 fpm
62.83
600 fpm
65.308
70.0162
77.285
81.828
40 MHz
33 MHz
25 MHz
20 MHz
1.239
1.07085
0.81125
0.649
67.8745
75.6625
80.53
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 18. Typical Ambient Temperatures for TQFP with 2-Layer Board
Am186/188EM and Am186/188EMLV Microcontrollers
57
AMD [ AMD ]
