Patent ID: 7994762
Filing Date: 2011-08-09
Classification: H02M

Abstract:
1. A DC to DC converter comprising: an inductor, first and second electrically controllable switches and a controller, wherein the first electrically controllable switch is interposed between an input node and a first terminal of the inductor and the second electrically controllable switch extends between a second terminal of the inductor and a common node or a ground, and where a first rectifier extends between the common node or ground and the terminal of the inductor and a second rectifier connects the second terminal of the inductor to an output node, wherein the controller controls the operation of the first and second switches to perform voltage step down or step up, as appropriate, to achieve a desired output voltage and wherein a decision about when to switch the first electrically controlled switch is made as a first function of a voltage error between the output voltage and a target output voltage, and an estimate of the current in the inductor (VCUR) based on both an estimate of a current flowing into the inductor and an estimate of a current from the inductor; a first sensing transistor connected to the first electrically controllable switch; a second sensing transistor connected in series with the first sensing transistor to form a common node; a first operational amplifier having an output connected to drive the second sensing transistor, having an inverting input connected to the common node, and having a non-inverting input connected to the first electrically controllable switch; a third sensing transistor connected to the second electrically controllable switch and the inductor; a fourth sensing transistor connected in series with the third sensing transistor to form a second common node; a second operational amplifier having an output connected to drive the fourth sensing transistor, having an inverting input connected to the second common node, and having a non-inverting input connected to a reference node of the output voltage, and wherein a voltage (VCUR