The results of a comprehensive investigation of spiral inductors are presented. A physically based model includes the self and mutual inductances, the capacitances between adjacent turns, the substrate capacitance, and the ohmic loss effects proposed. Heterogeneous simulation scheme, including circuit and device models during time and frequency domains, is successfully implemented in VHDL-AMS language and is simulated numerically in Simplorer platform.The model has been validated during frequency domain with measurement data of spirals having different geometries and various sizes. Moreover, the fabricated spiral inductors are evaluated in DC-DC power converter to benchmark the model accuracy. Simulation and experimental results show excellent agreement.Validity domain is discussed.
| INTRODUCTIONIn the work of Ouyang and Andersen, 1 they specified various problems related to the integration of power electronic systems. The authors demonstrated that the large mass/volume of a given power system is occupied by magnetic components. These components may be optimized using planar printed circuit board (PCB) devices. Compared with the conventional magnetic components, planar technology is printed directly on circuit board (PCB) with low profile and offers the flexibility of winding geometry and large shape. [1][2][3] From a design point of view, planar inductor electrical behavior cannot be precisely predicted by the conventional inductor models. [4][5][6] In particular, the skin, the proximity, and the parasitic capacitances effects are complex devices to model, particularly during large frequency domain. In the work of Han et al, 5 the electromagnetic simulation is considered to be modeling planar components. However, this method is not only cumbersome and time-consuming but also difficult to develop into general electronically circuit simulations. Other original models are reported by Wang et al. 6 However, this model is not dependent on the geometrical parameters and the layout process. Moreover, its model parameters are not used fairly to optimize the planar inductor layout. In a previous work, 3 a simple square planar inductor model is developed and simulated inside a power converter during time domain. 7 However, the validation process appeared quite limited at frequency domain and for different planar inductor structures such as hexagonal and octagonal structures (Figure 1). So far, literature has addressed models of planar inductor but was not able to simulate different inductor designs. It is thus necessary to assess the planar inductor electrical performances and its validation not only during time domain but also during frequency domain for different inductor structures.