Technique for smoothing frequency transitions during clock dithering

US11489533B2 · kind B2 · utility

Assignee

• Apple Inc. · US

Inventors

• Bogdan-Eugen Matei · Westerndorf, DE
• Hartmut Sturm · Germering, DE

Key dates

• Filing date: Apr 28, 2020
• Grant date: Nov 1, 2022
• Expiry date: May 19, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02M3/158
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

An apparatus includes a power converter circuit configured to generate a voltage level on a regulated power supply node using a clock signal, and a clock generation circuit configured to dither a frequency of the clock signal. To transition from a first frequency to a second frequency, the clock generation circuit is configured to change, during an initial transition period, the clock signal between the first and second frequencies such that a particular percentage of clock pulses have the second frequency. During one or more intermediate transition periods, the clock generation circuit is configured to change the clock signal between the first and second frequencies such that a percentage of clock pulses having the second frequency increases relative to a prior transition period. During a final transition period of the series, the clock generation circuit is configured to set the frequency of the clock signal to the second frequency.