Patent ID: 7141955

Claim:
A circuit for regulating an output signal, comprising: a switching buck regulator circuit that is coupled to an input node, wherein the switching buck regulator circuit is arranged to regulate the output signal, and to provide current sensing based, in part, on a current sense voltage; and wherein the switching buck regulator circuit includes a high-side switch; and a clamping circuit that is arranged to clamp the current sense voltage at the current sense node to a voltage level that is relatively near an input voltage at the input node if the high-side switch is open, wherein the high-side switch includes a high-side switch transistor; and wherein the switching buck regulator circuit further includes: a sense transistor that is coupled to the high-side switch transistor in a current mirror arrangement, wherein the sense transistor is coupled to a current sense node, and wherein the high-side switch transistor is coupled to a switch node; a sense branch transistor that is coupled between the current sense node and the input voltage node, wherein the sense branch transistor includes a gate, and wherein the current sense voltage is provided at the current sense node; and a current control circuit that is coupled to the current sense node.