AM186 Datasheet, PDF (61/112 Pages) Advanced Micro Devices – High-Performance, 80C186- and 80C188-Compatible, 16-Bit Embedded Microcontrollers with RAM

THERMAL CHARACTERISTICS
TQFP Package
The Am186ER and Am188ER microcontrollers are
specified for operation with case temperature ranges
from 0°C to +100°C for a commercial temperature
device. Case temperature is measured at the top
center of the package as shown in Figure 16. The
various temperatures and thermal resistances can be
determined using the equations in Figure 17 with
information given in Table 10.
θ_JA is the sum of θ_JC and θ_CA . θ_JC is the internal
thermal resistance of the assembly. θ_CA is the case to
ambient thermal resistance.
The variable P is power in watts. Typical power
supply current (I_CC) for the Am186ER and Am188ER
microcontrollers is 3.7 mA per MHz of clock frequency.
θ_JA
θ_CA
T_{C θJC}
θ_JA = θ_JC + θ_CA
Figure 16. Thermal Resistance (°C/Watt)
θ_JA = θ_JC + θ_CA
P = I_CC ⋅ freq (MHz) ⋅ V_CC
T_J = T_C + (P ⋅ θ_JC)
T_J = T_A + (P ⋅ θ_JA)
T_C = T_J – (P ⋅ θ_JC)
T_C = T_A + (P ⋅ θ_CA)
T_A = T_J – (P ⋅ θ_JA)
F ^{TA = TC – (P ⋅ θCA)}
Figure 17. Thermal Characteristics Equations
A _{Table 10. Thermal Characteristics (°C/Watt)}
Airflow
(Linear Feet
θ_JC
θ_CA
θ_JA
Package/Board
per Minute)
R 0fpm
7
38
45
PQFP/2-Layer
200 fpm
400 fpm
7
32
39
7
28
35
600 fpm
7
26
33
D ^0fpm
10
46
56
TQFP/2-Layer
200 fpm
400 fpm
10
36
46
10
30
40
600 fpm
10
28
38
0 fpm
5
18
23
PQFP/4-Layer
to 6-Layer
200 fpm
400 fpm
5
16
21
5
14
19
600 fpm
5
12
17
0 fpm
6
24
30
TQFP/4-Layer
to 6-Layer
200 fpm
400 fpm
6
22
28
6
20
26
600 fpm
6
18
24
T
Am186^TMER and Am188^TMER Microcontrollers Data Sheet
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