Abstract: A control circuit for adaptive noise margin control for a constant on time (COT) converter comprises an input reference terminal, amplifier, first switch device, voltage divider, trigger circuit, and output reference terminal. The amplifier has an input terminal coupled to the input reference terminal receiving a reference voltage signal. The first switch device has a control terminal coupled to an output of the amplifier, a first conduction terminal for receiving a voltage source signal, and a second conduction terminal. The voltage divider is coupled to the second conduction terminal and another input terminal of the amplifier. The trigger circuit, coupled to the voltage divider, is for triggering voltage change of a modified reference voltage signal selectively according to a high-side control signal of the COT converter. The output reference terminal coupled to the second conduction terminal outputs the modified reference voltage signal.

Abstract: A constant on time converter control circuit and a constant on time converter are provided. The constant on time converter control circuit comprises an error amplifier, a voltage to current converter, and an initial current source. The error amplifier is for receiving a reference voltage signal and a feedback voltage signal and outputting a compensated voltage signal. The voltage to current converter receives the compensated voltage signal and outputs a converted current signal. The initial current source provides an initial current signal. The initial current signal and the converted current signal form a new reference voltage signal. A constant on time OFF time comparator receives the new reference voltage signal and the feedback voltage signal and outputs a control signal. The control signal affects the turning on and turning off of electronic switches to produce an output voltage of a constant on time converter.

Abstract: A constant on time converter control circuit and a constant on time converter are provided. The constant on time converter control circuit comprises an error amplifier, a voltage to current converter, and an initial current source. The error amplifier is for receiving a reference voltage signal and a feedback voltage signal and outputting a compensated voltage signal. The voltage to current converter receives the compensated voltage signal and outputs a converted current signal. The initial current source provides an initial current signal. The initial current signal and the converted current signal form a new reference voltage signal. A constant on time OFF time comparator receives the new reference voltage signal and the feedback voltage signal and outputs a control signal. The control signal affects the turning on and turning off of electronic switches to produce an output voltage of a constant on time converter.

Abstract: A comparator circuit with dynamic biasing comprises a comparator, first dynamic biasing generator, first extra biasing device, second dynamic biasing generator, and second extra biasing device. The comparator includes a biasing circuit, input stage, active loads, and output terminal. The input stage has a first input terminal, second input terminal, first current path, and second current path. The comparator is configured to output an output signal at the output terminal according to the first input signal and second input signal. The first dynamic biasing generator is coupled between a first detection node and the first extra biasing device coupled to the biasing circuit. The second dynamic biasing generator is coupled between a second detection node and the second extra biasing device coupled to the biasing circuit. The first and second detection nodes are between the input stage and the active loads.

Abstract: A control circuit is introduced for facilitating inrush current reduction for a voltage regulator providing an output voltage variable in response to an output voltage selection. The control circuit includes a soft-start circuit, a soft-start tracking circuit, and a controller. The soft-start circuit is utilized for providing a soft-start signal. The soft-start tracking circuit includes a first input terminal for receiving a feedback signal from the voltage regulator, a second input terminal coupled to the soft-start circuit, and an output terminal coupled to the soft-start circuit. The controller, coupled to the soft-start tracking circuit, is configured to output an enabling signal to the soft-start tracking circuit selectively in accordance with the output voltage selection. The soft-start tracking circuit is operable in response to the enabling signal so that the soft-start signal provided by the soft-start circuit substantially follows the feedback signal from the voltage regulator.

Abstract: A control circuit is introduced for facilitating inrush current reduction for a voltage regulator providing an output voltage variable in response to an output voltage selection. The control circuit includes a soft-start circuit, a soft-start tracking circuit, and a controller. The soft-start circuit is utilized for providing a soft-start signal. The soft-start tracking circuit includes a first input terminal for receiving a feedback signal from the voltage regulator, a second input terminal coupled to the soft-start circuit, and an output terminal coupled to the soft-start circuit. The controller, coupled to the soft-start tracking circuit, is configured to output an enabling signal to the soft-start tracking circuit selectively in accordance with the output voltage selection. The soft-start tracking circuit is operable in response to the enabling signal so that the soft-start signal provided by the soft-start circuit substantially follows the feedback signal from the voltage regulator.

Abstract: The present application proposes a transient enhancing circuit for a constant-on-time converter. The constant-on-time converter includes an error amplifier and a comparator. The transient enhancing circuit includes a first sample-and-hold circuit and a zero-current detection circuit. The first sample-and-hold circuit has an input terminal and an output terminal. The input terminal of the first sample-and-hold circuit is coupled to an output terminal of the error amplifier, and the output terminal of the first sample-and-hold circuit is coupled to a first input terminal of the comparator. The zero-current detection circuit is coupled to the first sample-and-hold circuit and arranged for outputting a control signal when current flowing through a load of the constant-on-time converter is detected to be zero. The present application also proposes a constant-on-time converter using the transient enhancing circuit.

Abstract: A method for controlling an operating mode of a portable electronic device having a first plane and a second plane connected together comprises forming a magnet in the first plane, forming a magnetic flux sensor in a position of the second plane corresponding to the magnet for sensing magnetic flux, and controlling the operating mode of the portable electronic device according to the sensing result of the magnetic flux sensor.