Location: Dallas Texins Association at Texas Instruments
13900 N Central Expwy. (north-bound access road between Midpark Rd.
& Spring Valley Rd.)
Conference Room 1&2
Abstract:
A frequency and phase synthesis architecture has been developed
within TI in the past several years. It is commonly called
"flying-adder" architecture. This architecture is a frequency
synthesis technique that is based on PLL. The output frequency is
inversely proportional to the size of frequency digital control word.
It can be useful in applications that need a stable and
easilycontrolled clock source. It is especially useful for application
which needs a clock source of MANY frequencies. Since the invention of
this architecture, it has been utilized in many products and a series
of five papers have been published in IEEE journals. Due to the nature
of this technique, it is likely that many other designs might also
benefit from it.
The following four papers are available from IEEE Xplore:
1. Journal of Solid-State Circuits, June 2000, "An Architecture of
High-Performance Frequency and Phase Synthesis".
2. IEEE Transaction on VLSI System, Oct. 2002, "A Flying-Adder
Architecture of Frequency and Phase Synthesis with Scalability".
3. IEEE Transaction on Circuit And System II, March 2003, "A New
Frequency Synthesis Method Based on Flying-Adder Architecture".
4. Journal of Solid-State Circuits, March 2004, "A Novel All Digital
Phase Lock Loop with Software Adaptive Filter".
The first paper presents the foundation and the principle circuitry of
this architecture. The second paper improves the architecture greatly
in circuit level. The third paper presents an idea of overcoming the
inherent jitter problem of the architecture. In system-level, this
paper proposes a new frequency synthesis method that is directly
comparable to fractional-N PLL. This paper also solved a tough
mathematical problem that is related to frequency accuracy. (If you are
interested in this math problem and willing to provide better solution,
please see the attachment) The fourth paper demonstrated an exemplary
All Digital Phase Lock Loop by using this architecture as its DCO, or
Digital Control Oscillator. A fifth paper, "A Flying-Adder Frequency
Synthesis Architecture of Reducing VCO Stages", will be published in
IEEE Transaction on VLSI System in Feb. 2005. This paper presents a
technique of reducing the number of VCO stages without sacrificing the
available synthesizable frequencies.
This presentation is the summary of the above five papers.