Patent ID: 8564272

Claim:
A circuit for converting or amplifying power, comprising: a controlled circuit including a power converter; an error amplifier coupled to the controlled circuit and configured to provide an error amplifier signal to the controlled circuit, the error amplifier comprising: a first positive input terminal; a second positive input terminal coupled to the first positive input terminal; and a negative input terminal to receive a feedback signal related to an output of the power converter in the controlled circuit; and a soft-start circuit coupled to the error amplifier, and configured to provide a soft-start signal to at least one of the first positive input terminal and the second positive input terminal, wherein a difference between the soft-start signal and the feedback signal controls a switching duty cycle to limit inrush current of inductance and an overshoot voltage of the controlled circuit, and wherein the soft-start circuit includes a capacitor and a current divider having a bipolar transistor configured to receive a supply current and to provide at the base of the bipolar transistor a specific fraction of the received supply current according to the common emitter current gain of the bipolar transistor to charge the capacitor with the specific fraction of the supply current to provide the soft-start signal; wherein the controlled circuit, the error amplifier, and the soft-start circuit are each included in a same integrated circuit.