With more and more importance attributed to reduce energy consumption, power monitoring at various points of a system becomes mandatory. Precise power monitoring requires to measure the voltage drop over a current sense resistor as alternative concepts such as hall sensors or flux gate suffer from imperfections due to offset and gain drift.
Current measurement by means of a shunt resistor - as shown here – can be precise but has the obvious disadvantage to cause additional power loss due to the voltage drop across the sense resistor. Furthermore, at higher current levels as tens of amps, bulky sense resistors are required to cope with the dissipated power.
Reducing the resistor value allows to reduce the power loss - at the expense of dynamic range of the current measurement. Indeed, with external resistors, the smallest signal that can be resolved is often limited by parasitic board effects like thermocouples or limited noise immunity of the kelvin sense lines. Therefore current measurements with external sense resistors imposes a difficult tradeoff between additional power loss and precision of the current measurement. LTC2947 allows you to overcome this tradeoff between dynamic range and system efficiency by having an integrated 300uOhm resistor, providing a tiny, very accurate solution to monitor current, voltage, power, charge and energy in your system.