Method and device for measuring current for a dc-dc converter

A current sensing method for a DC-DC type converter comprising at least one connection module mounted between first and second potentials, wherein the connection module comprises at least one output node taken to an output potential and through which an output current passes, wherein the connection module is able to connect the output node to a first and a second potential, fixing the output potential respectively to a first and a second value,

• comprising at least the steps consisting of:
• connecting an intermediate node of an intermediate module to the first potential,
• connecting the intermediate node to the output node if the output node is connected to the first potential, or disconnecting the intermediate node from the output node if the output node is connected to the second potential,
• generating, at the intermediate node, an intermediate potential equal to a third or a fourth value, respectively correlated to the first or second value, wherein the difference between the third and the fourth value is smaller than the difference between the first and second values,
• sending the intermediate potential to a first input of an amplifying module,
• connecting a retroaction node from the amplifying module to the first potential if the output node is connected to the first potential, disconnecting the retroaction node from the first potential if the output node is connected to the second potential,
• taking the retroaction node to a third potential equal to the potential present on the first input, and
• generating, at the retroaction node, a mirror current proportional to the output signal.

A power supply, comprising:

• a supply input node;
• a supply reference node;
• a supply output node;
• a filter having an input node and having an output node coupled to the supply output node;
• a switching stage coupled between the supply input and reference nodes and operable to alternately couple the input node of the filter to the supply input node and supply reference node in response to a feedback signal;
• a first feedback stage coupled to the filter input node;
• and
• a second feedback stage coupled to the first feedback stage and operable to generate the feedback signal.

A system, comprising:

• a power supply, comprising
• a supply input node,
• a supply reference node,
• a supply output node,
• a filter having an input node and having an output node coupled to the supply output node,
• a switching stage coupled between the supply input and reference nodes and operable to alternately couple the input node of the filter to the supply input node and supply reference node in response to a feedback signal,
• a first feedback stage coupled to the filter input node, and
• a second feedback stage coupled to the first feedback stage and operable to generate the feedback signal;
• and
• a load coupled to the supply output node.

A method, comprising:

• generating a first signal that is related to a current flowing through a phase of a power supply;
• generating a second signal that is related to the first signal;
• and
• controlling the current flowing through the phase in response to the second signal.