A NEW SPICE SUBCIRCUIT MODEL OF POWER P-I-N-DIODE

A new modeling approach for power p-i-n diode is proposed. The base region is represented with a two-port network, obtained by solving the ambipolar diffusion equation with the Laplace transform method, and by approximating the resulting transcendental functions in the s-domain with rational approximations. Two different networks have been obtained. The first one, based on Taylor-series approximation, is shown to be a generalization of a two-port model already proposed in the literature for the nonquasi-static modeling of bipolar transistors. The second network representation is based on Pade' approximation and is shown to be more accurate than the Taylor-series approach. The obtained RLC networks are easily implemented in a PSPICE subcircuit which takes also into account the emitter recombination effects and the dynamic of the space-charge voltage build-up. Good agreement has been obtained by comparing the results of the proposed model with numerical device simulations.