FCX-1M targets compact RF and digital platforms where PCB area is limited but the design still needs predictable oscillator start-up and stable frequency performance across wide operating temperatures. Seam-sealed construction improves environmental robustness and helps maintain consistent characteristics over time.

Typical use cases include Wi-Fi/Bluetooth modules, wearables, smartphones, compact consumer devices, and IoT nodes using a discrete resonator as the reference for an SoC/MCU crystal oscillator (Pierce) or PLL.

The values on this page reflect common catalogue configurations. Final delivered specifications depend on the confirmed part suffix and the latest official datasheet.

Selection guidance

• FCX-1M when you want extra start-up margin (lower ESR) vs ultra-mini packages.
• FCX-1S when PCB area is the top constraint (1.2×1.0mm class).
• AEC-Q200 screening can be supported on request for automotive programs.

For portfolio navigation, see: Quartz Crystal Resonators and Timing Devices.

Related product links: FCX-1M • FCX-2M • FCX-2S

Engineering highlights

• Nominal frequency range: 24–60MHz.
• Frequency tolerance: ±10ppm @25°C (common option).
• Temperature stability options: ±15ppm (−40~+85°C), ±30ppm (−40~+105°C), ±80ppm (−40~+125°C).
• Load capacitance options: 6 / 10 / 18pF (custom CL available).
• Drive level guidance: 10µW typical, 200µW max (validate with your oscillator gain setting).
• ESR limits specified by frequency band to support start-up margin validation.

Production & compliance

• Package: 1.6×1.2×0.33mm SMD, reflow compatible.
• Seam-sealed with vacuum for enhanced reliability and moisture resistance.
• RoHS & REACH compliant, Pb-free documentation available.
• Lot traceability support for qualification and mass production.
• AEC-Q200 available (screening plan depends on program requirements).

Key specs (quick summary)

Typical reference test conditions: 25°C ±5°C, 40%–70% RH unless otherwise specified.

Load capacitance selection (CL)

Choose a crystal CL that matches the effective load at the IC pins: CL ≈ (C1·C2)/(C1+C2) + Cstray. For symmetric Pierce networks, C1 ≈ C2 is common.

• Include internal programmable caps (if any) and PCB stray capacitance in the estimate.
• When uncertain, validate two adjacent CL options (e.g., 10pF and 18pF) during EVT.
• Keep the layout symmetric to reduce mismatch and spurs.

Start-up margin, ESR & drive

• Check oscillator negative resistance margin against the crystal ESR (common practice: ≥ ~5× margin).
• Use the ESR band that matches your target frequency (see specs table) rather than a single broad ESR bucket.
• Control drive level: excessive drive can accelerate aging and shift frequency in ultra-small packages.
• Place FCX-1M close to XTAL pins; keep traces short, avoid vias, and keep away from DC/DC and high-speed clocks.

If you can share your IC’s oscillator negative-resistance guideline, FCom can help validate the configuration.

Mechanical

Pad function

Pin labeling may vary by drawing revision. Always follow the latest FCX-1M datasheet for your exact footprint and pad assignment.

Suggested PCB land pattern

Use your PCB stack-up and assembly capability to finalize stencil/aperture design. For oscillators sensitive to EMI/jitter, keep the crystal on a short, symmetric route and treat the area as a “quiet island”.

Reference only; confirm against the official mechanical drawing before locking the footprint.

Wireless modules & IoT nodes

Reference clocking for Wi-Fi / Bluetooth and connectivity chipsets where crystal tolerance and stability map to frequency error budgets and channel accuracy. Lower ESR bands support improved start-up margin in low-power designs.

• Wi-Fi / Bluetooth modules
• IoT sensors and gateways
• Smartphones and miniaturized embedded systems

Wearables & compact electronics

The 1.6×1.2mm footprint supports aggressive PCB miniaturization while providing practical margin on ESR and drive-level in always-on domains.

• Smartwatches / fitness trackers
• Compact medical wearables
• Space-limited consumer electronics
• Automotive ECUs (screening on request)

Related pages: Quartz Crystal Resonators • Timing Devices • Frequency Crystals Portfolio

Selection checklist

• Model: FCX-1M
• Frequency: ___ MHz (24–60MHz)
• Load Capacitance (CL): 6 / 10 / 18 pF (target)
• Tolerance: ±10 ppm (target)
• Temperature Range: −40~+85 / −40~+105 / −40~+125°C
• Packaging: Tape & Reel
• Annual Volume: ___ pcs

Selection Path / Upgrade Options

If footprint is tighter, consider FCX-1S. If you prefer a larger package for additional margin, compare FCX-2S and FCX-2M. For chipset-driven clock trees, use the MCU/SoC SMD crystal selection guide.

Procurement-friendly part description

If you need AEC-Q200 screening, specify your grade, sample plan and PPAP/traceability requirements.