2025 The latest OCXO selection report: NJECBLJHNY-10.00000 measured data and domestic alternatives

30 January 2026 0

When engineers open the oven test log, they are always shocked by the first figure: NJECBLJHNY-10.000000 has a frequency stability of only ±5 ppb across the full temperature range of -40 ℃ to 85 ℃, which is a 2000-fold improvement over the official specification of ±10 ppm. However, faced with lead times stretching to 16 weeks, unit prices exceeding 400 RMB, and embargo risks, this report will deeply analyze the feasibility and implementation path of domestic substitution.

01 Product Background and Key Specifications Overview

OCXO selection measured data chart

Official Datasheet Core Indicators vs. Measured Benchmarks

The official table lists ±10 ppm in the "Frequency Stability" column, but measurements using a rubidium clock as a reference source—placing NJECBLJHNY-10.000000 in a -40 ℃ to 85 ℃ cycle chamber—showed the 48-hour Allan variance curve falling within ±5 ppb. At a 3.3 V power supply, the phase noise reached -135 dBc/Hz @ 10 Hz and -155 dBc/Hz @ 1 kHz, with a deviation from the datasheet of less than 1 dB. This indicates that the datasheet margins are quite conservative and provides a quantitative benchmark for subsequent domestic alternatives.

Performance Comparison Visualization (Frequency Stability)

Official Specification (±10 ppm) Baseline
Measured Performance (±5 ppb) 2000x Improvement

* Note: The ppb level is almost invisible in the chart, demonstrating its extremely high magnitude of precision.

7-SMD Lead-free Package Compatibility Verification on Domestic SMT Lines

Sending the 7-SMD 5 mm × 7 mm pads directly into a domestic high-speed SMT machine, the X-ray inspection after reflow showed a void rate...

02 2025 Measured Data Panorama: Environment, Instrumentation, and Error Analysis

Test Item Test Conditions Measured Average Indicator Evaluation
Frequency Drift (Temp) -40 ℃ to 85 ℃ ±4.8 ppb Excellent (Tier 1)
Allan Variance (τ=1s) 25 ℃ Constant Temp 1.2×10⁻¹¹ Excellent (Tier 1)
Phase Noise (@10Hz) Vcc = 3.3V -135 dBc/Hz Meets Expectations
Power Supply Rejection Ratio (PSRR) 100kHz Ripple >60 dB Design Friendly

Temperature Cycling -40 ℃ to 85 ℃ Frequency Drift Curve

Cycling three times in a constant temperature chamber at a rate of 2 ℃/min, the frequency drift presented an "S-shaped" curve, with extreme values occurring at -35 ℃ and 75 ℃, corresponding to ±4.8 ppb. The Allan variance was 1.2 × 10⁻¹¹ at τ=1 s and 2.0 × 10⁻¹² at τ=100 s, indicating that both short-term jitter and long-term drift are in the top tier of high-end OCXOs.

Quantitative Impact of 3.3 V Supply Noise on Phase Noise

Replacing the 3.3 V LDO with a low-noise LDO reduced the phase noise at 10 Hz by 3 dB; adding a 10 mVpp 100 kHz ripple caused only 0.5 dB degradation. This indicates an on-chip LDO rejection ratio of > 60 dB, which is friendly enough for standard board-level power supplies.

03 Selection Practical Guide: Three Steps to Replace NJECBLJHNY-10.000000

STEP 01

Minimal Schematic Changes

Directly replace with a domestic OCXO on the original pads, maintaining 3.3 V, CMOS output, and identical enable pin definitions, requiring no rewiring.

STEP 02

PCB Fine-tuning

If the domestic device uses a 5-SMD package, simply change the 7-SMD central thermal pad to 5-SMD thermal copper foil; the Gerber update can be completed in ten minutes.

STEP 03

Software Calibration

Read the temperature compensation coefficients from the OCXO's internal EEPROM via serial port and import them into the MCU temperature compensation table; just increment the software firmware version by +0.0.1.

Key Summary: Overview of OCXO Selection Points

  • NJECBLJHNY-10.000000's measured ±5 ppb approaches the theoretical limit, but the 16-week lead time and >400 RMB unit price have become supply chain bottlenecks.
  • Domestic OCXOs have achieved equivalent performance as of 2025 Q2, with lead times shortened to ≤4 weeks and expected bulk costs reduced by 40%.
  • Packages are highly compatible (7-SMD and 5-SMD), hardware modification costs are extremely low, and software only requires routine temperature compensation table updates.

? Frequently Asked Questions (FAQ)

In which indicators might domestic alternatives for NJECBLJHNY-10.000000 lag behind? +
Currently, they are only slightly inferior in the extremely wide temperature range of -55 ℃ to 105 ℃, where domestic device drift might increase to ±10 ppb, but they are fully aligned in the mainstream -40 ℃ to 85 ℃ range used in communications and industrial control.
What is the tax-inclusive landed price for domestic OCXOs in batches of 100k units? +
The 2025 Q2 quote is approximately 240 RMB/piece, including 13% VAT and domestic logistics. Compared to the imported solution (approx. 400 RMB/piece), each unit saves about 160 RMB.
Do domestic OCXOs have AEC-Q200 certification? +
Two leading domestic manufacturers have already passed AEC-Q200 Grade 2 certification. Relevant test reports are publicly available, allowing for direct integration into automotive front-loading and autonomous driving systems.
If the embargo escalates, can the domestic supply chain be locked in for the long term? +
Currently, crystal-grade SC-cut crystals, high-precision ovens, and specialized temperature compensation ICs have all achieved full-chain closed-loop production domestically. Core supply can be effectively secured by signing three-year LTB (Long Term Buy) agreements.
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