Hi Expert,
According to below link:
http://processors.wiki.ti.com/index.php/AM57x_Thermal_Considerations
GP EVM used heat-sink CTS BDN10-3CB/A01 , based on heat-sink vendor info, its thermal resistance ( heat-sink case to ambient, R(ha)) is 26.4 C/W,
so in GP EVM case, R(ja) = R(jc)+ R(ch)+R(ha), here, R(ja) is AM5728 junction to ambient, R(jc) is AM5728 junction to its case, R(ch) is AM5728 case to heatsink, R(ha) is heatsink to ambient., obviously, total R(ja) >26.4 C/W
But according to AM5728 datasheet Table 5-18. Thermal Resistance Characteristics (ABC Package), AM5728 SOC R(ja) (Junction-to-free air ) is 11.1 C/W,
Question: why on AM5728 GP EVM, the designer choose a heatsink whose thermal resistance is much higher than AM5728 SOC itself? If without that heatsink, looks like AM5728 SOC heat resistance should have better data (11.1C/W < 26.4+ C/W)
Heat Sink and Fan Part Numbers
Tests conducted with a heat sink used the CTS BDN10-3CB/A01
