User`s manual

DIGITAL-LOGIC AG MSMP5 / P3 SEN/SEV Manual V1.6A
127
13 T HERMAL S PECIFICATIONS
Each product will undergo a BurnIn-Test of 10 cycles of 30 min. between the operating temperatures of –
25°C to +60°C or higher if extended ranges are requested.
The critical point is to meet the max. T(case) temperature of the CPU .
This temperature is specified by 90°C for the SQFP-case. The tables below show the allowable ambient
temperature at various airflows and with different heatsink configurations.
CPU: 166MHz Clock: 166MHz T (case) = 90°C Power Consumption: 7W
Temp.
ambient
Measured
Heatsink Temp. by
Ta=20°C
no Airflow
0 m/sec
Airflow
3 m/sec
Airflow
6 m/sec
Active
cooled
-E27
Heatsink horiz. 64°C 45°C 52°C 55°C
Heatsink vert. 58°C 50°C 53°C 55°C
13.1 Thermal analysis for case integration
Since the integrated heatsink is unidirectional, the airflow must be exactly in the direction of the heatrails. If
possible, mount the board vertically, so that the heatrails show up/down. The self produced airflow is around
3m/sec in this case.
Special attention must be given to the mounting of the PC-product in a fully closed case/box. The thermal
energy will be stored in the inner room of this environment.
If the case may have a fan:
1. The hot air must be exchanged with a filtered fan by cool air from outside.
2. The hot air must be cooled with a heat exchanger.
If the case may not have any fan or opening to exchange the hot air:
1. The heatsink of the CPU must be mounted directly to a heatsink integrated in the case.
The thermal energy does not go through the air. It will be conducted directly through the
alloy of the heatsink outside.
2. Diminish the thermal energy production by reducing the CPU performance.
Ex. using 66MHz clock only.