Inductor-based switching mode DC-DC converter and control method thereof

摘要

A DC-DC converter and a method of controlling an inductor-based switching-mode DC-DC converter in a discontinuous conduction mode are disclosed. In one aspect the method includes providing a DC-DC converter having a first and second switching elements, and, in each conversion cycle, first, turning on a first switching element, while maintaining a second switching element in off state, thereby increasing the current through an inductor. The method also includes detecting when a voltage signal at one connection node of the inductor reaches a first threshold value for the first time after the start of the conversion cycle, and turning on the second switching element, while maintaining the first switching element in off state, thereby decreasing the inductor current.

主权项

1. A method of controlling an inductor-based switching-mode DC-DC converter comprising an inductor, a first switching element and a second switching element, the switching elements being operationally coupled to the inductor so that the inductor is charged and completely discharged in each conversion cycle thereby operating the DC-DC converter in a discontinuous conduction mode, and the method comprising:
in each conversion cycle,
turning on the first switching element, while maintaining the second switching element in off state, thereby increasing the current through the inductor;turning off the first switching element, while maintaining the second switching element in off state;detecting when a voltage signal at one connection node of the inductor reaches a first threshold value for the first time after the start of the conversion cycle, and triggered by the first threshold value detection, turning on the second switching element, while maintaining the first switching element in off state, thereby decreasing the current through the inductor;detecting when the voltage signal reaches a second threshold value, and triggered by the second threshold value detection, turning off the second switching element, while maintaining the first switching element in off state;after detecting when the voltage signal reaches a second threshold value and triggered by the second threshold value detection, detecting when the voltage signal reaches a third threshold value, and triggered by the third threshold value detection, turning off the second switching element, while maintaining the first switching element in off state; andmaintaining the first and the second switching element in off state until the end of the conversion cycle.