Synthesized Current Sense Resistor for Wide Current Sense Range

摘要

A circuit has a first sense resistor circuit having components including a first-circuit active element to provide a sense resistance to sense a current in a load in series therewith, the sense resistance being established by an input command voltage. A second sense resistor circuit has components replicating the components of the first sense resistor circuit including a replicated active element, a resistance of the replicated active element also being established by the input command voltage. A precision resistor is coupled to the replicated active element to provide a load thereto. When the input command voltage establishes a voltage across the replicated active element, a voltage is established across the first-circuit active element in proportion thereto to command a desired current in the load.