Patent ID: 6879136

Claim:
An inductor current emulation circuit for a switched-mode power supply (SMPS), comprising: a SMPS which includes an inductor having first and second terminals and provides an output current at an output terminal, said SMPS arranged such that the current (I L ) in said inductor goes to zero at least once per switching cycle under static operating conditions, an RC integrator connected in parallel across said inductor, comprising: a resistor having first and second terminals, said resistor's first terminal connected to said inductor's first terminal, and a capacitor having first and second terminals, said capacitor's first terminal connected to said resistor's second terminal at a first node and its second terminal connected to said inductor's second terminal, a zero reset switch (ZRS) connected in parallel across said capacitor, and a control circuit coupled to said ZRS and arranged such that said ZRS is open when I L is essentially non-zero and such that said ZRS is closed during a least a portion of each switching cycle when I L is essentially zero such that said capacitor is substantially discharged, such that the voltage (V C ) across said capacitor emulates I L.