The measurement of the dynamic power consumption is a very important task for the characterization and optimization of an energy-autonomous system. In this paper a measurement system is presented that allows the simultaneous measurement of three current ranges from 1 µA to 30 mA at a sample rate of 1 MHz with a selectable supply voltage in the range of 1.8 V to 3.3 V. With this system the full range of low to high power consumption is covered with a high resolution in time, as it is present in a wireless sensor node during data acquisition and wireless communication, respectively.