Patent ID: 8159203

Claim:
A DC-DC converter, comprising: a first estimator unit configured to perform an accurate control signal estimation; a second estimator unit configured to perform a fast control signal estimation; a switching unit configured to switch to an output of the first estimator unit during substantially constant control signal conditions and to switch to an output of the second estimator unit during substantially changing control signal conditions to provide an estimation on the required control signal; an inductor and an output capacitor coupled to a load; wherein the first estimator unit is configured to estimate a required inductor current for a load by measuring a low frequency part of an inductor current; wherein the second estimator unit is configured to estimate a second required inductor current for a load by measuring voltage changes on the output capacitor; and wherein the second estimator unit receives the voltage of the output capacitor and the inductor current at the start and the end of a previous period and outputs an estimation on the required inductor current based on a subtraction of a capacitor current from the measured inductor current, wherein the capacitor current is determined by multiplying the voltage changes on the output capacitor with the value of the output capacitance and by dividing this by the time period.