{
  "id": 12892051,
  "title": "I keep seeing the same two oscillator selection mistakes in design reviews",
  "url": "https://urgent.news/2026/10/08/i-keep-seeing-the-same-two-oscillator-selection-mistakes-in-design",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-10-08T15:10:00.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/peterhu-ocxo/i-keep-seeing-the-same-two-oscillator-selection-mistakes-in-design-reviews-1km1"
  },
  "original_language": "en",
  "account": "Over the course of many design reviews, I have observed the same two oscillator selection errors recurring. One common mistake involves using an over-specification, where designers opt for a high-cost OCXO when a simpler, more affordable TCXO would suffice. This can lead to issues like reduced battery life and longer warm-up periods, as the excessive stability requirements are unnecessary for most consumer and industrial applications.\n\nOn the other hand, under-specification is equally problematic. Some engineers choose basic XOs or cheap TCXOs for critical applications, such as a 1GSPS ADC or a 5G small cell requiring Stratum 3E stability (±50ppb). Such decisions may seem reasonable at first glance, but they often result in significant SNR degradation and instability, with the true stability requirements only becoming apparent during debugging.\n\nA practical decision tree, developed after a decade of experience, can help guide oscillator selection. For designs requiring clock frequency control via voltage, a VCXO is recommended. If stability requirements exceed ±50ppb over a temperature range of -40 to +85°C, an OCXO is the appropriate choice. For devices needing to maintain time without GNSS for more than a few hours, an OCXO is also the better option. All other cases fall under the TCXO category. It is essential to remember the importance of warm-up time, as OCXOs can take anywhere from 20 seconds to 10 minutes to reach stable operating temperature. In situations where a device must boot and transmit within a single second, an OCXO may not be the optimal choice.",
  "summary": "After a few too many design reviews, I've noticed the exact same two mistakes come up over and over again: The \"just in case\" over-spec Someone will put a $150+ OCXO into a design that only needs ±2ppm stability. Then they wonder why their battery life dropped from 5 years to 6 months, and why the board needs a 5-minute warm-up before it's stable. The thing is: TCXOs are good enough for most…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}