This thesis will discuss the advantages (Field Programmable Processor Array) of smart fan via FPPA single chip. The functions of smart fan include:stepless velocity regulation of fan、temperature control、timer function,…etc. In this thesis, the differences will be compared between the DSP-chip with FPPA chip. The low cost for mass production is a main motivation for FPPA chip. In this thesis the lowest velocity of fan can be achieved to 160RPM.