There are two types of heat sinks, ATHS-1/2/105/66/30A and ATHS-1/2/105/66/30H4. The former is without any holes, and the latter has four holes. The heat sink’s thermal resistance is the most important parameter to choose heat sink. Once the maximum safe junction temperature for the equipment (Tjmax) is known, the power is going to dissipate (Pd) and the maximum ambient temperature will work at (Tamb).
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