Power distribution systems such as USB are ubiquitous. They can be found in automotive dashboards, home charging systems and office equipment. Cellphones, electric toothbrushes, PC printers and personal computers all use battery chargers.
These systems are designed to be inexpensive. They use the smallest number of wires and thinnest gauge possible and often have connectors that are prone to high resistivity. The IR drops in these wires and connectors reduces the voltage and power available for charging or may drop to the point where charging is impossible.
Existing solutions for this wire drop include Kelvin sensing regulators and LTC’s virtual remote sense chip, the LT®4180. These solutions can be expensive or difficult to incorporate into a design. The LT6110 is compatible with any single or dual wire power cable and is small (SOT23 and 2x2 DFN), inexpensive and easy to implement.
The LT6110 is flexible and allows for good correction in systems where the component values are not well known. For well-understood or stable systems, the correction can be extraordinary, at well under 1% error even with large IR drops.