A smart quick soft-start circuit for digital control DC-DC converter

This paper presents a smart quick soft-start method for the digital control dc-dc converter. For the soft-start operation, it is important to detect the load resistor R. In the conventional analog control method, the fixed large time constant of the soft-start circuit must be set corresponding to the worth condition. In this proposed digital control, the optimal time constant of the soft-start circuit can be decided by detecting R dynamically with the control processor. Therefore, it doesn´t need to set the large value for the time constant. From simulation results, it is confirmed that the digital control method has superior soft-start characteristics compared to the analog one and the convergence time of output voltage is approximately 94% smaller than the analog one.