A new digital soft-start characteristics for current mode DC-DC convertert

Abstract

This paper presents a new soft-start method for the current mode digital control dc-dc converter. For the soft-start operation, it is important to detect the load current. In the analog control method, the fixed parameter of the soft-start circuit must be set. In the proposed digital control in the current mode control, the load resistor can be calculated with the output voltage and output current. The optimal upper limit of the digital feedback can be decided by load resistor value. Compared with the optimal upper limit to the digital feedback value, the digital value of the switching signal is determined to prevent the inrush current and overshoot of output voltage. It is confirmed that the proposed digital control method has superior soft-start characteristics from the simulation results.