Current-sensing techniques for DC-DC converters

Current sensing is one of the most important functions on a smart power chip. Conventional current-sensing methods insert a resistor in the path of the current to be sensed. This method incurs significant power losses, especially when the current to be sensed is high. Lossless current-sensing methods address this issue by sensing the current without dissipating the power that passive resistors do. Six available lossless current sensing techniques are reviewed. A new scheme for increasing the accuracy of current sensing when the discrete elements are not known is introduced. The new scheme measures the inductor value during the DC-DC controller startup.

[1]  A. Prodic,et al.  Digital PWM controller and current estimator for a low-power switching converter , 2000, COMPEL 2000. 7th Workshop on Computers in Power Electronics. Proceedings (Cat. No.00TH8535).

[2]  Enrico Dallago,et al.  Lossless current sensing in low-voltage high-current DC/DC modular supplies , 2000, IEEE Trans. Ind. Electron..

[3]  F. C. Lee,et al.  A low voltage high efficiency and high power density DC/DC converter , 1997, PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing and Electronic Specialists Conference 1972.

[4]  Pallab Midya,et al.  Sensorless current mode control-an observer-based technique for DC-DC converters , 1997 .

[5]  Duncan A Grant,et al.  Dynamic performance of current-sensing power MOSFETs , 1988 .

[6]  H.A. Owen,et al.  Switching Regulators I , 1979, 1979 IEEE Power Electronics Specialists Conference.

[7]  S. Siskos,et al.  On-chip overcurrent and openload detection for a power MOS high-side switch: a CMOS current mode approach , 2002 .

[8]  Gordon W. Roberts,et al.  The current conveyor: history, progress and new results , 1990 .

[9]  Peng Xu,et al.  A novel current-sharing control technique for low-voltage high-current voltage regulator module applications , 2000 .

[10]  P. Midya,et al.  Sensorless current mode control-an observer-based technique for DC-DC converters , 1997, PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing and Electronic Specialists Conference 1972.

[11]  A. S. Sedra,et al.  The current conveyor: history and progress , 1989, IEEE International Symposium on Circuits and Systems,.

[12]  S. Yuvarajan,et al.  Power conversion and control using a current sensing power MOSFET , 1991, [1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems.

[13]  S. Yuvarajan,et al.  Performance analysis and signal processing in a current sensing power MOSFET (SENSEFET) , 1991, Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting.

[14]  Robert G. Meyer,et al.  Analysis and Design of Analog Integrated Circuits , 1993 .

[15]  Duncan A Grant,et al.  Current sensing MOSFETs for protection and control , 1991 .