Alpha and Omega Semiconductor (cayman) Ltd.

Alpha and Omega Semiconductor International LP

Bu-Wei Chen

Jung-Pei Cheng

Yueh-Ping Yu

A switching frequency controller, a voltage converter, and a method are used for controlling switching frequency. The switching frequency controller includes a frequency divider, a frequency detector, an accumulation counter, and an on-time controller. The frequency divider generates a divisional signal having a divisional frequency according to an input signal having a target frequency. The target frequency is 2times of the divisional frequency. The frequency detector receives the divisional frequency and a switching control signal, and calculate a number of periods that pass by during each cycle of the divisional signal. The number of periods is represented by (N+1) bits. The accumulation counter increases or decreases a control indication value by a predetermined value according to a most significant bit of the number of periods. The on-time controller adjusts an on-time length of the switching control signal according to the control indication value.

Switching frequency controller, voltage converter, and method for controlling switching frequency

A detection circuit for detecting an inductor current flowing through an inductor is provided. The inductor is coupled to a switch. The detection circuit includes a comparison circuit and a signal generating circuit. The comparison circuit, having a first node, is configured to compare a conduction time of a diode of the switch with a time threshold to provide a first voltage at the first node. The signal generating circuit, coupled to the first node, is configured to output a first detection signal according to the first voltage. The first detection signal indicates whether the inductor current flowing through the inductor reaches a first current threshold. A switching regulator comprises the detection circuit. A control method controls the switching regulator.

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Zhubei, Taiwan

Bu-Wei Chen