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.