Abstract: A switching power regulator and method for recovering the regulator from an unregulated state while preventing overshoot of an output voltage is provided. The regulator includes a dropout detector, a sample-and-hold circuit, a voltage offset circuit and a soft start circuit. When the regulator enters an unregulated state, the dropout detector detects when a pulse width modulation (PWM) signal stops toggling. The sample-and-hold circuit and soft start circuit are used to effectively clamp the voltage at the output of an error amplifier. This causes the output of the error amplifier to regulate around a desired voltage so that the regulator recovers from the unregulated state with little or no overshoot of the output voltage. In another embodiment, a method for recovering from the unregulated state is provided.

Abstract: A switching power regulator and method for recovering the regulator from an unregulated state while preventing overshoot of an output voltage is provided. The regulator includes a dropout detector, a sample-and-hold circuit, a voltage offset circuit and a soft start circuit. When the regulator enters an unregulated state, the dropout detector detects when a pulse width modulation (PWM) signal stops toggling. The sample-and-hold circuit and soft start circuit are used to effectively clamp the voltage at the output of an error amplifier. This causes the output of the error amplifier to regulate around a desired voltage so that the regulator recovers from the unregulated state with little or no overshoot of the output voltage. In another embodiment, a method for recovering from the unregulated state is provided.

Abstract: Embodiments of a switched-mode power supply and a method for operating a switched-mode power supply involve synchronizing a phase and frequency of an asynchronous controller of the switched-mode power supply with a clock signal of a synchronous controller of the switched-mode power supply while the asynchronous controller is in control of a power stage of the switched-mode power supply, concurrent with synchronizing the phase and frequency of the asynchronous controller with the clock signal of the synchronous controller, presetting a state variable of the synchronous controller while the asynchronous controller is in control of the power stage of the switched-mode power supply, and switching control of the power stage from the asynchronous controller to the synchronous controller after the phase and frequency of the asynchronous controller are synchronized with the clock signal of the synchronous controller and after the state variable of the synchronous controller is preset.