Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Left Crossing (s) (s)

Required number input.

Right Crossing (s) (s)

Required number input.

Find the horizontal eye opening between the latest left crossing and earliest right crossing in one unit interval. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Eye Width (s) (s)

The resulting eye width (s) returned as a number.

• Setup, hold, jitter, and eye estimates require a consistent timing reference and sign convention. Clock uncertainty, skew, data-dependent jitter, process-voltage-temperature corners, routing, crosstalk, and statistical margins must come from the implementation and interface specification.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• USB Eye Jitter Budget

  Subtract a required open-eye width and other timing penalties from one unit interval to obtain remaining total jitter budget. All inputs are in picoseconds; apply the limits from the relevant USB generation and test specification.

• Eye Height Estimate

  Find the vertical eye opening at the sampling instant as the minimum high level minus the maximum low level; a negative value means overlapping level distributions.

• Inter Symbol Interference Penalty

  Express horizontal or vertical eye-opening loss as an equivalent amplitude penalty in decibels using matching eye-opening measurements.