Current measurments in switching regulators

A method of supplying power comprising:

• generating a voltage between a first terminal and a second terminal of a switching transistor in response to a current between the first terminal and second terminal, wherein the first terminal receives a first voltage, the second terminal is coupled to a switching node, and a control terminal receives a control voltage to turn the switching transistor on and off;
• closing a first switch coupled between the second terminal of the switching transistor and a first terminal of a current measurement circuit when the switching transistor is turned on, wherein a second terminal of the current measurement circuit is coupled to the first terminal of the switching transistor;
• and
• closing a second switch coupled between the first terminal of the current measurement circuit and the second terminal of the current measurement circuit when the switching transistor is turned off;
• wherein when the switching transistor is on the first switch is closed and the second switch is open, and when the switching transistor is off the first switch is open and the second switch is closed.

A circuit comprising:

• a switching regulator comprising a switching means for selectively coupling a first voltage to a switching node, the switching means having a first terminal configured to receive the first voltage and a second terminal coupled to the switching node;
• means for measuring current in the switching means comprising a first terminal and a second terminal;
• first means for selectively coupling a switching voltage on the switching node to the first terminal of the means for measuring current;
• and
• second means for selectively coupling the first terminal and the second terminal of the means for measuring current together,
• wherein when the switching means couples the first voltage to the switching node the first means couples the switching voltage to the first terminal of the means for measuring current and the second means does not couple the first terminal and the second terminal of the means for measuring current together, and
• wherein when the switching means does not couple the first voltage to the switching node the first means does not couple the switching voltage to the first terminal of the means for measuring current and the second means couples the first terminal and the second terminal of the means for measuring current together.