P R E L I M I N A R Y
Table 15 shows typical maximum ambient temperatures in degrees Centigrade for a TQFP package used on a 2-
layer board. The typical ambient temperatures are based on a 100-degree Centigrade maximum case temperature.
Figure 16 graphically illustrates the typical temperatures in Table 15.
Table 15. Typical Ambient Temperatures (°C) for TQFP with a 2-Layer Board
Linear Feet per Minute Airflow
Microcontroller
Speed
Typical Power
(Watts)
0 fpm
45.7
55.2
66.1
72.9
200 fpm
57.5
400 fpm
64.6
600 fpm
67.0
40 MHz
33 MHz
25 MHz
20 MHz
1.2
1.0
0.7
0.6
65.0
70.8
72.7
73.5
77.9
79.4
78.8
82.3
83.5
85
75
65
55
■
■
◆
■
◆
◆
■
◆
✶
●
✶
●
✶
●
✶
●
45
35
Legend:
● 40 MHz
✵ 33 MHz
◆ 25 Mhz
■ 20 MHz
0 fpm
200 fpm
600 fpm
400 fpm
Airflow (Linear Feet Per Minute)
Figure 16. Typical Ambient Temperatures for TQFP with a 2-Layer Board
54
Am186ED/EDLV Microcontrollers
AMD [ AMD ]
