An event-driven simulation methodology for integrated switching power supplies in SystemVerilog

Emerging power-supply-on-chip applications such as on-chip DCDC conversion, energy harvesting, and LED drivers use switching regulator ICs integrated with digital controllers. Although the resulting mixed-signal systems call for efficient system-level behavioral simulation, this remains difficult due to the fast switching and slow transients of the regulator and the high complexity of the controller. This paper presents a truly event-driven approach for modeling and simulating such integrated power systems entirely in SystemVerilog. By modeling various switching regulator topologies as switched linear networks whose responses can be expressed as a sum of complex exponentials, ct^m-1e^-atu(t), the accurate voltage/current waveforms can be captured by updating the coefficients, c, at each input or switching event. The model is applied to two examples, a power factor corrector and switched-capacitor DC-DC converter, and the results demonstrate that the proposed simulator can achieve 20~100× improvements in speed while maintaining SPICE-level accuracy in evaluating power efficiency, steady-state ripples, and power factor.