23.3 A 0-to-60V-Input VCM Coulomb Counter with Signal-Dependent Supply Current and ±0.5% Gain Inaccuracy from -50°C to 125°C

Most battery-powered systems require measurement of the battery's state of charge, (SOC). A straightforward way to determine SOC is to keep track of the current flowing in and out of a battery, a method known as coulomb counting. Compared to other methods such as voltage or impedance monitoring, coulomb counting is simple to implement, does not require complex algorithms and is independent of cell chemistry. However, coulomb counters must operate continuously and essentially integrate forever; traditionally, their relatively high power consumption (several tens of µA e.g. [1]–[3]) and susceptibility to drift in the presence of offset have prevented their more widespread use.