Winding AC resistance of low temperature co-fired ceramic inductor

With the increased popularity of portable electronics, improved integrated solutions are desirable in order to improve the low power DC/DC converter technology. With the state-of-the-art designs, bulky magnetic components are major barriers for integrating the DC/DC converter into a single chip. In order to reduce the inductor size to help integration, and achieve more a compact POL, pushing the frequency to Mega Hz is one solution and is the future trend in the industry. A low profile inductor with a low temperature co-fired ceramic (LTCC) ferrite material is one of the promising candidates for high frequency applications. In order to optimize the low profile LTCC inductor design for high frequency integration, the winding ac resistance needs to be studied. This paper studies the winding ac resistance for several low profile LTCC inductor structures. The impact of winding shape and core material on winding ac resistance are studied carefully based on FEA simulation. Some simple but accurate enough analytical equations are also proposed to predict winding ac resistance for low profile LTCC inductor.