AN279 Silicon_Laboratories, AN279 Datasheet
AN279
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AN279 Summary of contents
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... may be specified as either an RMS or peak-to-peak quantity may be specified as either an RMS or peak-to-peak PER Clock Period Distribution Figure 1. RMS Period Jitter Example Copyright © 2006 by Silicon Laboratories AN279 σ (RMS) = σ J PER PER AN279 ...
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... AN279 3. Basic Approach By definition, period jitter compares two similar instants in time of a clock source such as two successive rising edges or two successive falling edges. Since the two instants are separated in time by approximately one period reasonable to expect that higher frequency jitter components will contribute more to period jitter than lower- frequency jitter components (f< ...
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... By numerical integration, we can determine that the integrated phase noise under the entire SSB phase noise curve from 160 MHz yields a total phase noise power = –54.46 dBc. This "brick wall" integration is equivalent to wideband RMS phase jitter of 2.663 ps or 0.00268 radians. 2 (πfτ) weighting factor in dB Rev. 0.1 AN279 3 ...
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... AN279 By contrast weight L(f) using the period jitter weighting function and integrate the resulting curve over 160 MHz, we obtain a total phase noise power = –56.84 dBC, equivalent to RMS period jitter of 2.025 ps or 0.00204 radians; so, we can estimate the period jitter as being roughly 2 ps RMS, based solely on the available phase noise measurement ...
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... S – cos 2 f RMS 0 ∞ ∫ ϕ ϕ π τ Δ ) sin f RMS 0 ∞ ∫ ϕ ϕ π τ Δ ) sin f RMS ϕ ( )> radians t + < t > τ Rev. 0.1 AN279 5 ...
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... AN279 ∞ ∫ ϕ π τ Δ )df = sin f RMS 0 Now, convert back to time units: ∞ ⎛ ⎞ ∫ ϕ Δt Δ ------ 2 ----- - sin = = ⎝ ⎠ RMS π RMS 2 2 π 0 where f and f are the practical lower and upper frequency integration limits. ...
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... RMS_TOTAL RMS_NOISE RMS_1 or ∑ Δt Δt Δ RMS_TOTAL RMS_NOISE Δt J (rms) = PER_TOTAL RMS_TOTAL π τ sin π … Δt … Δ RMS_i RMS_N 2 RMS_i Rev. 0.1 AN279 spur below: 7 ...
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... AN279 C I ONTACT NFORMATION Silicon Laboratories Inc. 4635 Boston Lane Austin, TX 78735 Tel: 1+(512) 416-8500 Fax: 1+(512) 416-9669 Toll Free: 1+(877) 444-3032 Email: VCXOinfo@silabs.com Internet: www.silabs.com The information in this document is believed to be accurate in all respects at the time of publication but is subject to change without notice. ...