Voltage supply interface with improved current sensitivity and reduced series resistance

Abstract

A voltage supply interface provides both coarse and fine current control with reduced series resistance. The voltage supply interface has a segmented switch having N component switches that are digitally controlled. The voltage supply interface replaces a conventional sense resistor with a calibration circuit that has a replica switch that is a replica of the N component switches. The calibration circuit includes a reference current IREF that is sourced through the replica switch. A feedback amplifier forces a common voltage drop across the replica switch and the n-of-N activated component switches so that the cumulative current draw through the segmented switch is n·IREF. The current control of the voltage interface can be coarsely tuned by activating or deactivating component switches, and can be finely tuned by adjusting the reference current. The current sense resistor is eliminated so that the overall series resistance is lower.

Dependencies are inferred from the claim text.