Accurate high-side current emulation with auto-conversion for smart power stage applications

A current detection circuit for detecting a current in a Switch Mode Power Supply (SMPS), wherein the SMPS has a first switch and a second switch coupled in series and an output filter including an inductor and a capacitor coupled to a switch node formed by the first and second switches, the current detection circuit comprising:

• a current sensing circuit configured to sense a current across the second switch and generating a current sensing signal indicating current information of the second switch, wherein the current sensing circuit has an input to couple to the switch node and an output to provide the current sensing signal;
• and
• a current emulation circuit configured to emulate current information of the first switch, wherein the current emulation circuit has a first input configured to receive the current sensing signal, and an output to provide a current emulation signal indicating current information of the first switch, wherein the current emulation signal comprises an AC portion and a DC portion of the current information of the first switch, and wherein the current emulation circuit comprises an inductance sensing circuit for acquiring a real-time rate of change in current, and an AC emulation circuit for computing the AC portion of the current information of the first switch based on the real-time rate of change in current.