Adaptive soft-start characteristics of digital control DC-DC converter

This paper presents adaptive soft-start characteristics of digital control dc-dc converter. For the soft-start operation, it is important to detect the load resistor. In conventional analog method, the fixed large parameter of the soft-start circuit must be set by the condition. In the proposed digital control, the load resistor can be calculated with the output voltage and output current, and the optimal time constant of the soft-start circuit can be decided by detecting load dynamically in voltage mode. Therefore, it doesn´t need to set large value for the time constant. In the current mode control, the optimal upper limit can be decided by load resistor. It is confirmed that the digital control methods have superior soft-start characteristics compared to the analog one.