Multivariable controller design of a SIMO converter in order to implement in inertial measurement unit

A small switching DC-DC power supply which provides different output level is a good alternative in navigation systems. Single inductor multi output (SIMO) converters can be good for existing parallel output configurations in these applications. In this paper, a multivariable control based on signal flow graph modelling is used to reduce the cross regulation problem of a step down single inductor multi output converter. The multi-stages operation of SIMO converters cause, to achieve the model which predicts their all behaviors, be more difficult than typical converters. By SFG method, all small-signal transfer functions can be derived. In the other hand, designing a controller to control each output independently needs an accurate model to predict all behavior of the converter. In this paper a buck/buck SIMO converter is modeled by SFG. An effort has been made to compare modelling results between SFG and state-space averaging method in a buck/buck structure. Then, a multivariable controller scheme based on SFG model is designed to eliminating the cross regulation of the outputs. Simulation results are included to show the validity of the obtained model and designed controller.