Solving the IoT Power Consumption Measurement Challenges

The growth of objects connected to the internet is expected to exceed 20 billion devices by 2020  and continue to have double-digit growth rates. Many of these devices will be wearable devices, portable medical devices, and battery-operated industrial sensor/transmitters. For these devices, maximizing battery life is essential.

To meet the design requirements for battery life, the designer needs to be able to determine the total power consumption that the device is drawing. The designer needs to measure the load current in all the operating states of the device. That includes the very low currents, such as microamps when the device is in its sleep mode states as well as currents which can be in the amps range when the device is in its active, operating modes.  Furthermore the load currents are short bursts that can last for only 10's of microseconds when the device is transmitting data. Thus both high sensitivity and speed are needed to capture all the power the device consumes in all its operating states.

In addition, the characteristics of the battery impact the performance of the device, particularly near the end of the battery's life or discharge cycle. One way to account for the characteristics of the battery is to simulate the battery so that testing of the device is performed under the most realistic conditions.