National Instruments Corporation
Multi-phase noise cancelled adjustable switched mode programmable load

Abstract:

Circuits and methods for operating a programmable load circuit that includes a plurality of sub-circuits connected in parallel between an input and an output. Each sub-circuit may include an inductor, a load, and a switch coupled to the inductor. Each switch may be configurable in a first state and a second state, wherein the inductor is either connected to the output through the load or connected to the output through a connection that bypasses the load. The switches of the plurality of first sub-circuits may be programmable to periodically switch between the first state and the second state according to a duty cycle, and the switches may be out of phase with each other by a predetermined amount. The duty cycle may be programmable to tune the load of the programmable load circuit.