Table 16 shows typical maximum ambient temperatures in degrees Centigrade for a TQFP package used with a
4-layer to 6-layer board. The typical ambient temperatures are based on a 100-degree Centigrade maximum case
temperature. Figure 21 illustrates the typical temperatures in Table 16.
Table 16. Typical Ambient Temperatures for TQFP with Four-Layer to Six-Layer Board
Linear Feet per Minute Airflow
Microcontroller
Speed
Typical Power
(Watts)
0 fpm
84.1
200 fpm
85.5
400 fpm
86.8
600 fpm
88.1
50 MHz
40 MHz
33 MHz
25 MHz
0.662
0.522
0.432
0.342
87.44
89.64
91.84
88.5
89.5
90.6
90.5
91.4
92.2
92.5
93.2
93.9
97
96
95
94
93
◆
◆
◆
✶
●
92
91
◆
✶
●
✶
●
90
89
✶
●
■
88
87
86
■
Legend:
■
■ 50 MHz
● 40 MHz
85
84
✵ 33 MHz
◆ 25 Mhz
■
0 fpm
200 fpm
600 fpm
400 fpm
Airflow (Linear Feet Per Minute)
Figure 21. Typical Ambient Temperatures for TQFP with Four-Layer to Six-Layer Board
66
Am186TMER and Am188TMER Microcontrollers Data Sheet
AMD [ AMD ]
