AM186 Datasheet, PDF (65/112 Pages) Advanced Micro Devices – High-Performance, 80C186- and 80C188-Compatible, 16-Bit Embedded Microcontrollers with RAM

Table 15 shows typical maximum ambient temperatures in degrees Centigrade for a PQFP 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 20 illustrates the typical temperatures in Table 15.
Table 15. Typical Ambient Temperatures for PQFP with Four-Layer to Six-Layer Board
Microcontroller
Speed
50 MHz
40 MHz
33 MHz
25 MHz
Typical Power
(Watts)
0.662
0.522
0.432
0.342
0 fpm
88.0
90.6
92.3
93.8
Linear Feet per Minute Airflow
200 fpm
400 fpm
89.4
90.7
91.6
92.7
93.1
93.9
94.5
95.2
600 fpm
92.0
93.7
94.9
95.9
97
96
95
94
x
93
I
92
91
q
90
D ^Legend:
s 50 MHz
q 40 MHz
H 33 MHz
x 25 Mhz
89
88
s
87
0 fpm
x
x
I
T ^x
I
q
I
F^q
s
q
s
R ^As
200 fpm
400 fpm
Airflow (Linear Feet Per Minute)
600 fpm
Figure 20. Typical Ambient Temperatures for PQFP with Four-Layer to Six-Layer Board
Am186^TMER and Am188^TMER Microcontrollers Data Sheet
65