Full-time inductor current monitoring method by sensing low side switch

摘要

Aspects of the present disclosure describe a SMPS system, comprising a SMPS and an inductor current sensing device. The SMPS comprise a high-side (HS) switch and a low-side (LS) switch coupled in series and an output filter including an inductor and a capacitor coupled to a switch node formed by the HS and LS switches. An inductor current is supplied by the inductor to a load. The inductor current sensing device coupled across the LS switch has a first input configured to receive a node signal indicating a voltage level at the switch node, a second input configured to receive an input voltage of the system and a third input configured to receive an output voltage of the system. The inductor current sensing device is configured to obtain a first constant DC slope information, a second constant DC slope information and a valley current information based on the first input, second and third inputs, and generate an output signal based on the first constant DC slope information, the second constant DC slope information and the valley current information. The output signal has a triangular waveform including a rising slope and a falling slope proportional to rising and falling slopes of the inductor current.