MC68020 Motorola, MC68020 Datasheet - Page 277

• Manufacturer Part Number: MC68020
• Description: (MC68020 / MC68EC020) MICROPROCESSORS USERS MANUAL
• Manufacturer: Motorola

Table 10-2 shows the relationship between clock speed and power dissipation for any
package type. The worst case operating conditions are used for thermal management
design, while typical values are used for reliability analysis.
Table 10-3 shows the relationship between board temperature rise and power dissipation
in the test environment for the CQFP package. Derate q
in the application by adding (0.8/P
table. Board temperature was measured on the top surface of the board directly under the
device.
Values for thermal resistance presented in this document were derived using the
procedure described in Motorola Reliability Report 7843, ÒThermal Resistance
Measurement Method for MC68XX Microcomponent Devices,Ó and are provided for
design purposes only. Thermal measurements are complex and dependent on procedure
and setup. User-derived values for thermal resistance may differ.
MOTOROLA
Rated Frequency (MHz)
*
Natural convection
Table 10-1. q
Maximum
Typical
No Heatsink
With Heatsink
No Heatsink
With Heatsink
T
Table 10-3. Temperature Rise of Board vs. P
ba
Natural Convection
(°C)ÑNo Heatsink
33
25
20
16
Table 10-2. Power vs. Rated Frequency
q
JA
JA
ÑMC68020 CQFP Package
(at T
vs. AirflowÑMC68020 CQFP Package
M68020 USERÕS MANUAL
D
) * [T
J
Maximum = 110°C)
P
D
Maximum (Watts)
ba(application)
0.6W
46
35
43
32
0
18
Airflow in Linear Feet/Minute
*
1.4
1.2
1.0
0.9
1.0W
Ð T
P
27
200
28
20
25
17
D
JA
ba(table)
based on measurements made
P
D
Typical (Watts)
1.75W
53
] to the q
0.84
0.72
0.60
0.54
500
24
18
21
15
D
JA
values in the
10-3