Skew input offset voltage in current-sense amplifiers
Certain applications require that you calibrate the input offset voltage (VOS) of a current-sense amplifier to enhance the accuracy of its current measurements. This calibration, however, is hampered by interactions between the amplifier's minimum output voltage (VOL) and its input VOS at zero current. This article presents a simple method for "skewing" the input VOS of a unidirectional current-sense amplifier. The method lets you measure input VOS without the usual limitations due to VOL, and also improves the overall measurement accuracy.