A novel current sensing circuit for a current-mode control CMOS DC-DC buck converter

A novel on-chip current-sensing technique, which is suitable for a current-mode control CMOS DC-DC buck converter, is presented in this paper. The proposed current sensing circuit doesn´t need an op amp as a voltage mirror, and thus fewer transistors are need and lower power consumption is achieved. We use the TSMC 0.35μm 2P4M CMOS process to design and simulate the converter circuits. Simulation results show that accuracy of current-sensing for the proposed circuit is 98.2% and the core circuit´s power consumption is only 81.22mW. Under the same technology and the operating conditions, the performance of the proposed circuit is the best compared to the other circuits.