Patent ID: 7119522

Claim:
A circuit for switched buck regulation, comprising: an inductor circuit that is arranged to provide an inductor current; a capacitor circuit that is arranged to provide an output voltage from the inductor current; a bottom-side switch circuit that is coupled between a ground node and the inductor circuit, wherein the bottom-side switch is arranged to open and close responsive to a first switch control signal; a top-side switch circuit that is coupled between the inductor circuit and an input node, wherein the top-side switch circuit is configured to receive an input voltage at the input node; and wherein the top-side switch circuit is arranged to open and close responsive to a second switch control signal; a current sense amplifier circuit that is arranged to sense a current across the bottom-side switch circuit, and further arranged to provide a current sense voltage in response to the current; a sample-and-hold circuit that is arranged to sample the current sense voltage if the bottom-side switch is closed, and further arranged to hold the current sense voltage if the bottom-side switch is open, wherein the sample-and-hold circuit is arranged to provide a sample-and-hold signal; an analog current multiplier circuit that is arranged to provide control current; a ramp generator circuit that is arranged to provide a ramp voltage base in part on the control current and the sample-and-hold signal; and a switch control circuit that is configured to provide the first and second switch control signals based in part on the ramp voltage.