GXLV Datasheet, PDF (209/247 Pages) National Semiconductor (TI) – Geode™ GXLV Processor Series Low Power Integrated x86 Solutions

Package Specifications (Continued)
Example 1
Assume P (max) = 5W and T_A (max) = 40°C.
Therefore:
θ_CA = -^T---^C------_P^–-----T----^A--
θ_CA = ⁽---8---5----–5-----4---0----⁾
Example 2
Assume P (max) = 10W and T_A (max) = 40°C.
Therefore:
θ_CA = -^T----^C-----_P^–-----T----^A--
θ_CA = ⁽---8---5----–9-----4---0----⁾
θ_CA = 9
θ_CA = 5
In this case, the heatsink under consideration is more than
adequate since at 5W worst case, it can maintain a 40°C
case temperature rise above ambient (θ_CA = 9) when a
maximum of 45°C (θ_CA = 8) is required.
In this case, the heatsink under consideration is NOT ade-
quate to maintain the 45°C case temperature rise above
ambient for a 9W processor.
For more information on thermal design considerations or
heatsink properties, refer to the Product Selection Guide of
any leading vendor of thermal engineering solutions.
Revision 1.1
209
www.national.com