Invention Grant
- Patent Title: Direct digital synthesis with reduced jitter
- Patent Title (中): 直接数字合成,减少抖动
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Application No.: US11454357Application Date: 2006-06-16
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Publication No.: US08352526B1Publication Date: 2013-01-08
- Inventor: Peter H. Alfke
- Applicant: Peter H. Alfke
- Applicant Address: US CA San Jose
- Assignee: Xilinx, Inc.
- Current Assignee: Xilinx, Inc.
- Current Assignee Address: US CA San Jose
- Agent Thomas A. Ward; John J. King
- Main IPC: G06F1/02
- IPC: G06F1/02

Abstract:
A direct digital synthesis is provided with added circuitry to reduce jitter in an IC so that a programmable frequency output can be provided near the limits of the IC system clock with minimal jitter. The system derives the quotient Q as a remainder R in an accumulator at the instant of an overflow, divided by a programmable input N. The quotient Q is subjected to conversion logic that can be provided by a fast parallel to serial converter such as, for example a multi-gigabit transceiver (MGT) of an FPGA. As an alternative to an MGT, a series of delay devices such as found in a carry chain can be used if calibration is performed to assure the accuracy of delays.
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