Patent ID: 8976819
Filing Date: 2015-03-10
Classification: G01R

Abstract:
1. A circuit, comprising: a current detection module configured to generate a first current detection signal of a first current flowing through a first power line, and a second current detection signal of a second current flowing through a second power line; a multiplexer configured to periodically switch between the two current detection signals in response to a control signal, and to output the first current detection signal within a first duration of each cycle of the control signal and output the second current detection signal within a second duration of each cycle of the control signal; a signal processing module configured to generate an energy accumulation signal according to an output of the multiplexer and a voltage detection signal of a voltage of the first power line; and a control module configured to provide the control signal to the multiplexer, and to generate an effective value of the second current during the second duration which is determined as a function of a change rate of the energy accumulation signal and an effective value of the voltage of the first power line; wherein the effective value is given by and wherein ΔE/ΔT denotes the change rate of the energy accumulation signal, and U denotes the effective value of the voltage of the first power line.