Thermal Power of Mobile Application Processor

Abstract

Until recently, heat dissipation performance of the conventional mobile AP (Application Processor) and mobile phone hasen't been a critical issue because the level of heat generated from a low-frequency, single core AP was insignificant. However, as the mobile AP consumes more power by adopting high frequency multi-core CPU (Central Processing Unit) and GPU (Graphic Processing Unit), the heat dissipation performance of its application set, such as smart phone and tablet PC (Personal Computer) became a critical issue. The conventional stand alone type applications sets such as desktop PCs and servers could afford additional thermal management tools such as heat sink, heat pipe and cooling fan to improve thermal performances. On the contrary, the limited inside space of mobile set doesn't allow the use of conventional cooling methods so that the feasible thermal solutions for the mobile AP and mobile sets are limited. In addition, since mobile set is normally in contact with human skin during its operation, the criterion, Tcsmax (Maximum Case Skin Temperature) which determines the thermal power per-formance of the mobile set is different from the conventional criterion, Tjmax (Maximum Junction Temperature) of CPU. Therefore, the thermal performance of mobile AP and its mobile set should be carefully determined to satisfy the Tcsmax by considering AP operation power and heat dissipating performance of the its application set. This paper shows how to define the thermal power performance of mobile AP and its mobile application set and which technologies are important for future mobile AP and its application sets.