Variable off-Time Peak Current Mode Control (VoT-PCMC) as method for average current regulation in Buck Converter Drivers

Abstract

In automotive industry, every electronic device is driven by power switches. Indeed, the energy source is the car battery and it cannot, for instance, limit the output maximum voltage level. Consequently it could be higher than that supported by the load. The DC/DC Buck converter acts by limiting the output variables, according with the load specifications thereby ensuring its correct operation. The overall circuit will be composed of a power stage, the basic DC/DC converter, and a control loop, to provide a target output current value. This paper presents a control algorithm derived from an improved Peak Current Mode Control. The proposed algorithm defined Variable off-Time Peak Current Mode Control (VoT-PCMC) allows to contemporarily control in a DC-DC converter the ripple and the average current values, leading to a reliable load driver. The algorithm operation is simulated and then tested on hardware using dSpace, a Rapid Control Prototyping set-up.