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7
Industrial
Grade
MGDI-10 Standard Input Series
Gaia Converter FC97-006.03/06 Revision M
©
5
9- Thermal Characteristics
Characteristics
Conditions
Limit or typical
Performances
Operating ambient temperature
range at full load
Ambient temperature *
Minimum
Maximum
- 40°C
+ 71°C
Operating case temperature
range at full load
Case temperature
Minimum
Maximum
- 40°C
+95°C
Storage temperature range
Non functionning
Minimum
Maximum
- 40°C
+ 105°C
Thermal resistance
Rth case to ambient in free air
natural convection
Typical
12°C /W
Note * : The upper temperature range depends on configuration, the user must assure a max. case temperature of + 95°C.
10
100
30
80
70
60
90
20
40
50
25%
75%
50%
100%
Power (W)
Temperature (˚C)
Full load ambient temperature without derating : 71˚C
Maximum case temperature : 95˚C
Natural convection operation area
Additionnal cooling operation area
Maximum storage temperature : 105˚C
The MGDI-10 series operating case temperature must not exceed 95°C. The maximum ambient temperature admissible for
the DC/DC converter corresponding to the maximum operating case temperature of 95°C depends on the ambient airflow,
the mounting/orientation, the cooling features and the power dissipated.
To calculate a maximum admissible ambient temperature the following method can be used. Knowing the maximum case
temparature Tcase = 95°C of the module, the power used Pout and the efficienc
y
η :
• determine the power dissipated by the module Pdiss that should be evacuated :
Pdiss = Pout(1/
ηηηηη - 1)
• determine the maximum ambient temperature :
Ta = 95°C - Rth x Pdiss
where Rth is the thermal resistance from the case to ambient.
The previous thermal calculation shows two areas of operation :
• a normal operation area in a free natural ambient convection (grey area in this following graph),
• an area with cooling features (air flow or heatsink) ensuring a maximum case temperature below the maximum
operating case temperature of 95°C (white area in the following graph).