Crystal Aging Frequency Change
Calculate signed measured frequency change in ppm relative to the initial frequency: 1e6 × (aged − initial) / initial. Measurements must use the same conditions; this does not predict an aging curve.
Description
Oscillator aging compares frequencies measured at different times under comparable conditions.
Oscillator aging compares frequencies measured at different times under comparable conditions.1
Calculate signed measured frequency change in ppm relative to the initial frequency: 1e6 × (aged − initial) / initial. Measurements must use the same conditions; this does not predict an aging curve.
When to use Crystal Aging Frequency Change
Use this tool to calculate signed measured frequency change in ppm relative to the initial frequency: 1e6 × (aged − initial) / initial. Measurements must use the same conditions; this does not predict an aging curve.
Prepare comparable frequency measurements or the nominal bus bit rate in the units requested.
How to use Crystal Aging Frequency Change and understand its results
- Prepare comparable frequency measurements or the nominal bus bit rate in the units requested.
- Enter initialFrequencyHz, agedFrequencyHz using the field table and calculation rules, then run the tool.
- Read agingPpm. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| initialFrequencyHz | Initial measured frequency. (Hz) | number; strictly above: 0 | Required |
| agedFrequencyHz | Frequency measured after aging. (Hz) | number; strictly above: 0 | Required |
Enter positive finite frequencies in Hz; return signed ppm drift.
ppm=1,000,000(aged−initial)/initial Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| agingPpm | Signed relative frequency change. (ppm) | number |
{
"input": {
"initialFrequencyHz": 10000000,
"agedFrequencyHz": 10000020
},
"output": {
"agingPpm": 2
}
}Limitations and assumptions
No aging curve, temperature compensation or future stability is predicted.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use LIN Bus Bit Time: Calculate nominal LIN bit duration as 1e6 / bit rate in microseconds, for the documented 1–20 kbit/s range. Frame overhead and clock tolerance are excluded. For a complementary task, use Balance–Spring Temperature Rate Change: Estimate relative period and rate change from T proportional to the square root of balance inertia divided by hairspring stiffness, using caller-supplied first-order coefficients.
References
-
Crystal Aging Frequency Change — tool.io
Similar or alternative tools
- LIN Bus Bit Time
Calculate nominal LIN bit duration as 1e6 / bit rate in microseconds, for the documented 1–20 kbit/s range. Frame overhead and clock tolerance are excluded.
- Balance–Spring Temperature Rate Change
Estimate relative period and rate change from T proportional to the square root of balance inertia divided by hairspring stiffness, using caller-supplied first-order coefficients.