Agilent Make High Sensitivity 252C Wide Dynamic Range Current Measurement - Application Note 5991-1951EN c20 free download

File name Make High Sensitivity_252C Wide Dynamic Range Current Measurement - Application Note 5991-1951EN c20

Keysight Technologies New Probing Technology Enables High Sensitivity, Wide Dynamic Range Current Measurement Application Note Introduction As modern battery-powered devices and integrated circuits become more green and energy efficient, there is a growing need to make high sensitiv- ity, low level current measurements to ensure these devices' current consumption is within acceptable limits. The key applications calling for accurate power consumption measurement are battery-powered applica- tions such as wireless mobile devices and consumer electronics. To maxi- mize the battery life, engineers need to minimize the power consumption over the life of the product. Power is defined as P = V x I. The key enabler of reducing the power consumption of a device is to lower the average current consumption for a fixed supply voltage level. A primary challenge in measuring the current consumption of battery- powered mobile devices, such as a cell phone or a tablet computer, is that the dynamic range of the current signal is very wide. The mobile device typically switches back and forth between active states, where it draws very high and fast peak currents, and an idle or standby current mode, where it draws very small DC and AC currents. Figure 1 shows the current drain measured on a GSM cell phone when making a call. The active current peaks as high as ~2 A, and at idle mode, the current drain is extremely small. Figure 1 The current drain measured on a GSM cell phone when making a call. 02 A simple way to measure a current with an oscilloscope is to use a clamp-on type current probe such as the Keysight Technologies, Inc. 1147B or N2893A to directly monitor the current going into the device. Unfortunately, this approach is not appropriate for measuring small currents that rapidly change between sub-milli amps and several amps because of the limited dynamic range and sensitivity of the clamp-on type current probe, which is limited to a few milli amps. In the example for measuring the current consumption of