Patent ID: 8917077

Claim:
A multi-phase switching regulator, comprising: a plurality of switch sets for generating an output voltage at an output node, wherein each switch set includes at least one power switch and a phase node, and each switch set receives a corresponding driving signal to operate the corresponding at least one power switch thereof for generating the output voltage; a plurality of output inductors, which are coupled between the corresponding phase nodes and the output node respectively; a pulse width modulation (PWM) circuit for generating a plurality of PWM signals to control the plurality of switch sets; and a droop circuit for providing a droop signal, the droop signal being related to a sum of currents through the phase nodes, the droop circuit including: a plurality of phase resistors, which are respectively coupled between the corresponding phase nodes and a common node, and each of which is for sensing a current generated by the corresponding switching set through the corresponding phase node; a droop capacitor, which is coupled between the common node and the output node; a phase buffer circuit, which has a common node terminal coupled to the common node for receiving a common node voltage at the common node, wherein the phase buffer circuit generates a first voltage according to the common node voltage; an output buffer circuit, which has an output node terminal coupled to the output node for receiving the output voltage, wherein the output buffer circuit generates a second voltage according to the output voltage; and a converter circuit, which receives the first voltage and the second voltage and generates the droop signal; wherein there is no substantial current flowing through the common node terminal and the output node terminal.