Internet of Things sensors will have to operate at very low powers to extend battery life for months, or make do with energy harvested from the environment. But that means that they’ll need to draw a wide range of electrical currents. Researchers from MIT developed a new step-down power converter that features a variable clock that can run switch controllers at a wide range of rates.
If no device is drawing current from the converter, or if the current is going only to a simple, local circuit, the controllers might release between 1 and a couple hundred packets per second. But if the converter is feeding power to a radio, it might need to release a million packets a second. In the MIT chip, access is granted to the voltage divider only for the fraction of a second that a measurement requires. The result is a 50 percent reduction in quiescent power.