Aperture-jitter SNR depends on the product of input frequency and timing uncertainty. Comparing it with quantization SNR shows the dominant limit.
How to read it
The waveform view shows timing error turning into amplitude error at high frequency.
The SNR curve shows where jitter falls below the quantization limit.
The error cloud shows sample-value scatter caused by timing uncertainty.
Learn ADC Sampling Jitter SNR by dialogue
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When reading ADC Sampling Jitter SNR, where should I look first? Moving Input frequency changes both the plots and the result cards.
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Start with Jitter SNR, but do not treat the number as the whole answer. Use Sampled waveform with jitter to confirm the assumed state, then read SNR limit curve for the distribution or trend. The waveform view shows timing error turning into amplitude error at high frequency.
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I can see why Input frequency changes Jitter SNR. How should I judge the influence of Sampling rate?
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Move Sampling rate in small steps and watch Quantization SNR. That reveals which term is controlling the result. Aperture-jitter SNR depends on the product of input frequency and timing uncertainty. Comparing it with quantization SNR shows the dominant limit. A single operating point is not enough; sweep the realistic scatter range.
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What is Sample error cloud for? It feels like the ordinary curve already tells the story.
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Sample error cloud is for finding boundaries where the condition becomes risky or margin collapses quickly. The SNR curve shows where jitter falls below the quantization limit. In Clock-jitter budgeting for high-speed ADCs, the important question is often what happens after a small change, not only the nominal value.
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So if Jitter SNR is within the target, can I accept the condition?
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Treat this as a first-pass review. It helps with ENOB estimation for RF/IF sampling and Comparing clock sources against SNR requirements, but final decisions still need standards, measured data, detailed analysis, and vendor limits. The error cloud shows sample-value scatter caused by timing uncertainty.
Practical use
Clock-jitter budgeting for high-speed ADCs.
ENOB estimation for RF/IF sampling.
Comparing clock sources against SNR requirements.
FAQ
Start with Jitter SNR and Quantization SNR. Then use Sampled waveform with jitter to confirm the assumed state and SNR limit curve to read distribution or bias. The waveform view shows timing error turning into amplitude error at high frequency
Move Input frequency alone, then move Sampling rate by a comparable amount and compare the change in Jitter SNR. Sample error cloud shows combinations where margin or performance changes quickly.
Use it for Clock-jitter budgeting for high-speed ADCs. Instead of trusting a single point, widen the input range and check whether Jitter SNR keeps enough margin before moving to detailed analysis.
Aperture-jitter SNR depends on the product of input frequency and timing uncertainty. Comparing it with quantization SNR shows the dominant limit. Final decisions still require standards, measured data, detailed analysis, and vendor limits.
How to Use
Enter signal frequency (fin) in MHz—typical range 1–500 MHz for RF/analog applications
Set sampling frequency (fs) in MHz, ensuring fs ≥ 2×fin to satisfy Nyquist criterion
Input timing jitter in picoseconds (ps)—realistic values: 1–100 ps for precision ADCs
Click Simulate to compute jitter-induced SNR degradation and effective ENOB loss
Review Combined SNR curve and compare against ideal quantization-only SNR baseline
Worked Example
A 12-bit ADC sampling a 200 MHz sine wave at fs=1 GHz with 10 ps RMS jitter: Quantization SNR = 6.02·12+1.76 = 74.0 dB. Jitter SNR = −20·log₁₀(2π·fin·σ_jitter) = −20·log₁₀(2π·200 MHz·10 ps) ≈ 38.0 dB, which dominates. Combined SNR ≈ 38.0 dB and effective ENOB ≈ 6.02 bits — a ~6-bit loss driven entirely by jitter. Reducing jitter to 1 ps at 100 MHz raises jitter SNR to ≈ 64.0 dB and ENOB to ≈ 10.4 bits, showing how strongly ENOB depends on the fin·σ_jitter product.
Practical Notes
Jitter impact scales with input frequency: 10 ps jitter degrades 500 MHz signals 5× worse than 100 MHz signals
For instrumentation (oscilloscopes, spectrum analyzers), jitter below 1 ps RMS is critical above 1 GHz sampling
Phase-locked loop (PLL) design dominates jitter budget; separate white jitter (broadband) from deterministic jitter (periodic) when modeling real clock sources
Interleaved ADCs with multiple clock domains can reduce effective jitter by √N but introduce channel mismatch errors above 5 GHz
At Nyquist frequency (fs/2), any jitter causes catastrophic SNR collapse; avoid sampling near fs/2 in production systems