Cantor Colburn LLP
Control circuit for switching power supply
A soft-start circuit generates a soft-start voltage Vss having a voltage level that rises over time. A pulse width modulator generates a PWM signal having a duty ratio adjusted such that a feedback voltage Vout′ that corresponds to the output voltage Vout of the switching power supply matches the soft-start voltage Vss. A driver circuit controls a switching element according to the PWM signal. A capacitor is arranged such that one terminal thereof is set to a fixed electric potential. A current source generates a charge current that flows intermittently in synchronization with the PWM signal so as to charge the capacitor. The soft-start circuit outputs, as the soft-start voltage Vss, a voltage that occurs at the capacitor.
Rohm Co., Ltd.
Y H H H
Y02B H02M H05B H02M
additional additional inventional inventional
Naoki Daisuke Hiroki
Inoue Uchimoto Kikuchi