Adaptive slope compensation for high bandwidth digital current mode controller

An adaptive slope compensation method for digital current mode control of dc-dc converters is proposed in this paper. The compensation slope is used for stabilizing the inner current loop in peak current mode control. In this method, the compensation slope is adapted with the variations in converter duty cycle. The adaptive slope compensation provides optimum controller operation in term of bandwidth over wide range of operating points. In this paper operation principle of the controller is discussed. The proposed controller is implemented in an FPGA to control a 100 W buck converter. The experimental results of measured loop-gain at different operating points are presented to validate the theoretical performance of the controller.

[1]  P. Mattavelli,et al.  Small-signal Laplace-domain model for digital predictive current mode controls , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[2]  Morten Nymand,et al.  A new simple and high performance digital peak current mode controller for DC-DC converters , 2014, 2014 IEEE Applied Power Electronics Conference and Exposition - APEC 2014.

[3]  R. D. Middlebrook,et al.  Topics in Multiple-Loop Regulators and Current-Mode Programming , 1987, IEEE Transactions on Power Electronics.

[4]  M. Hallworth,et al.  Microcontroller-Based Peak Current Mode Control Using Digital Slope Compensation , 2012, IEEE Transactions on Power Electronics.

[5]  Raymond B. Ridley,et al.  A new small-signal model for current-mode control , 1990 .

[6]  P. Mattavelli,et al.  External ramp autotuning for current mode control of switching converters , 2013, 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[7]  Yen-Shin Lai,et al.  Predictive Digital-Controlled Converter With Peak Current-Mode Control and Leading-Edge Modulation , 2009, IEEE Transactions on Industrial Electronics.

[8]  Cecil Deisch,et al.  Simple switching control method changes power converter into a current source , 1978, 1978 IEEE Power Electronics Specialists Conference.

[9]  Aleksandar Prodic,et al.  Predictive digital current programmed control , 2003 .

[10]  J. Bocker,et al.  Adaptive digital slope compensation for peak current mode control , 2009, 2009 IEEE Energy Conversion Congress and Exposition.

[11]  S. Saggini,et al.  An innovative digital control architecture for low-Voltage, high-current DC-DC converters with tight voltage regulation , 2004, IEEE Transactions on Power Electronics.

[12]  Fazel Taeed.  Design and Implementation of Digital Current Mode Controller for DC-DC Converters , 2015 .

[13]  Morten Nymand,et al.  A novel high performance and robust digital peak current mode controller for DC-DC converters in CCM , 2014, 2014 IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL).