OCXO vs TCXO — What's the Difference?

OCXOs and TCXOs are both designed to solve the same basic problem — quartz crystals drift in frequency as temperature changes — but they solve it in very different ways, with different trade-offs.

How an OCXO handles temperature

An OCXO (Oven-Controlled Crystal Oscillator) physically holds the crystal at a fixed, constant temperature inside a small internal heater. Since the crystal never actually experiences the outside temperature swings, its frequency stays extremely stable.

How a TCXO handles temperature

A TCXO (Temperature-Compensated Crystal Oscillator) takes a different approach: it measures the crystal's actual temperature and electronically corrects the output frequency in real time to compensate for the expected drift. There's no heater and no warm-up time.

Comparing the two

• Stability: OCXOs are significantly more stable than TCXOs — often by one or two orders of magnitude.
• Power consumption: TCXOs use far less power, since there's no heater to run continuously. This makes them the natural choice for battery-powered and portable equipment.
• Size: TCXOs are typically much smaller than OCXOs.
• Warm-up time: OCXOs need a brief period after power-on for the oven to reach temperature. TCXOs are ready almost instantly.
• Cost: TCXOs are generally more cost-effective for applications that don't need OCXO-level stability.

Which one do you need?

If your application is portable, battery-powered, or space-constrained — and doesn't require the very tightest stability — a TCXO is usually the right choice. If you're building RF, telecom, aerospace, or test equipment where long-term stability and low phase noise are critical, an OCXO is worth the extra size, power, and cost.

Vikronix supplies both

Browse our OCXO range or TCXO range, or get in touch if you're not sure which fits your application — we're happy to help you choose.