Power conversion including sensing a load current and adapting output voltage based on the load current

#The application refers to a power conversion arrangement, a power management circuit and a method for power conversion.

#In today's power management systems combinations of a switching converter, like a DC/DC converter, with a cascaded linear regulator are common. The DC/DC converter is primarily used to provide a sufficient power conversion to a higher or lower voltage with respect to a supplied voltage. The linear regulator, for example a low drop-out regulator, LDO, is cascaded in series to this switching converter to provide a voltage with accurate output having lower ripple. The output voltage provided by the combination is provided accurately with almost zero ripple.

#In known implementations of such cascaded power management systems the switching converter's output voltage is fixed. The linear regulator is designed such that a minimum drop-out voltage across this linear regulator is realized for a predefined peak load current. This results in power inefficiency for all load conditions other than the peak load.

#The text below explains aspects of the invention in detail using exemplary embodiments with reference to the drawings. Components and circuit elements that are functionally identical or have the identical effect bear identical reference numbers. In so far as circuit parts or components correspond to one another in function, a description of them will not be repeated in each of the following figures. Therein:

#FIG. 1 shows an exemplary embodiment of a power conversion arrangement according to the proposed teaching;

#FIG. 2 shows a second exemplary embodiment of a power conversion arrangement according to the proposed teaching;

#FIG. 1 shows an exemplary embodiment of the power conversion arrangement according to the proposed teaching. The power conversion arrangement comprises a switching converter DC, a linear regulator LDO1, a component MSI for sensing a load current Iload and a unit MVA for influencing a first output voltage Vout1. The switching converter DC has an input which is supplied with an input voltage Vin. The input voltage Vin is supplied by an energy source BAT which can be connected to the input of the switching converter DC. The switching converter DC furthermore has a first output Out1 to provide the first output voltage Vout1. The linear regulator LDO1 is connected with its input to the first output Out1 of the switching converter DC. The linear regulator LDO1 has a second output Out2 to provide a second output voltage Vout2. An electrical load CS can be connected to the second output Out2. The electrical load CS and the energy source BAT are each connected to a reference potential terminal 10 with their respective second terminals. At the second output Out2 a load current Iload is provided to the electrical load CS.

#The component MSI for sensing the load current Iload is connected to the second output Out2. The unit MVA for influencing the first output voltage Vout1 is connected to the component MSI for sensing the load current Iload and in a loopback connection to the first output Out1.

#The switching converter DC changes the input voltage Vin into the first output voltage Vout1 according to the operating mechanism of a switching converter, for example a DC/DC converter, known to those skilled in the art. The linear regulator LDO1 therefrom generates the second output voltage Vout2 as a function of the first output voltage Vout1. The component MSI for sensing the load current Iload senses the load current Iload at the second output Out2 of the linear regulator LDO1. The unit MVA for influencing the first output voltage Vout1 adjusts the first output voltage Vout1 as a function of the sensed load current Iload.