Qualcomm Incorporated

Michael Bui

Chunping Song

Stuart Pullen

Jialei Xu

Steve Hawley

Methods and apparatus for current sensing and error correction in a switched-mode power supply composed of a high-side transistor coupled to a low-side transistor are described. One example method generally includes capturing a current associated with the low-side transistor at a first time corresponding to the low-side transistor turning off; capturing a current associated with the high-side transistor at a second time corresponding to a first delay after the high-side transistor turns on; capturing the current associated with the high-side transistor at a third time corresponding to the high-side transistor turning off; and applying a first correction current to a current-summing node of the current-sensing circuit for a first interval based on the first delay, wherein the first correction current is based on the captured current associated with the low-side transistor at the first time and on the captured current associated with the high-side transistor at the second time.

Lossless average input and output current sensing in a switched-mode power supply

Certain aspects of the present disclosure provide methods and apparatus for current sensing and error correction, or at least adjustment, for a switching regulator. One example current-sensing circuit generally includes a first amplifier, a buffer, a low-pass filter, a first switch coupled between an output of the first amplifier and an input of the buffer, a second switch coupled between the output of the first amplifier and an input of the low-pass filter, a third switch coupled between an output of the buffer and the input of the low-pass filter, and a fourth switch coupled between the input of the low-pass filter and a reference node for the circuit.

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San Diego, CA, United States of America

Michael Bui