Invention Grant
- Patent Title: Clock divider circuit with synchronized switching
- Patent Title (中): 时钟分频电路同步切换
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Application No.: US14638284Application Date: 2015-03-04
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Publication No.: US09306574B1Publication Date: 2016-04-05
- Inventor: Feng Zhao , Raman S. Thiara
- Applicant: Apple Inc.
- Applicant Address: US CA Cupertino
- Assignee: Apple Inc.
- Current Assignee: Apple Inc.
- Current Assignee Address: US CA Cupertino
- Agency: Meyertons, Hood, Kivlin, Kowert & Goetzel, P.C.
- Agent Erik A. Heter
- Main IPC: H03K21/00
- IPC: H03K21/00 ; H03K23/00 ; H03K25/00 ; H03K21/02 ; H03K3/037 ; H03L7/00

Abstract:
The clock divider circuit includes a dividing circuit, a selection circuit, and a synchronization circuit. The dividing circuit is configured to receive an input clock signal at a first frequency, and to produce a number of different periodic signals based thereon. The selection circuit is configured to receive various ones of the periodic signals. An output clock signal may be provided from the selection circuit based on a selection made therein. The input clock signal may have a frequency that is an integer multiple of the output clock frequency. The selection circuit is configured to provide the output clock signal at different, selectable frequencies. The synchronization circuit may control the timing of the switching of the output clock signal from one frequency to the next so that such switching may be performed without glitches.
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