Patent ID: 9184651
Filing Date: 2015-11-10
Classification: G01R,H02M

Abstract:
1. A current detection circuit for detecting a current in a SMPS, wherein the SMPS having a first switch and a second switch, the current equaling a first switch current flowing through the first switch when a PWM signal is in a first state and equaling a second switch current flowing through the second switch when the PWM signal is in a second state different from the first state, the current detection circuit comprising: a current sensing circuit for sensing the second switch current, the current sensing circuit having a first input, a second input and an output, wherein the first input of the current sensing circuit is coupled to a first end of the second switch, the second input of the current sensing circuit is coupled to a second end of the second switch, and the output of the current sensing circuit is configured to provide a current sensing signal indicative of the second switch current; and a current emulation circuit having an input and an output, wherein the input of the current emulation circuit is configured to receive the current sensing signal, and the output of the current emulation circuit is configured to provide a current emulation signal, wherein the current emulation circuit provides a first current generated based on the current sensing signal and provides a second current generated based on the first current, and further wherein the current emulation signal is generated based on the first current and the second current; wherein the current detection circuit is configured to provide a current detection signal indicative of the current in the SMPS, and wherein the current detection signal is proportional to the current emulation signal with a predetermined proportion during a first period, and the current detection signal is proportional to the current sensing signal with the same predetermined proportion during a second period.