For design engineers

• Common CL options (6 / 7 / 9 / 12.5 pF) to match mainstream RTC/MCU oscillator networks.
• ESR ≤ 65 kΩ and max drive 1.0 µW to support start-up and long-term stability.
• Predictable parabolic temperature behavior for practical timekeeping error budgeting.

For procurement & program teams

• Standardized 6914 SMD format for automated placement and reflow workflows.
• RoHS & REACH documentation and lot traceability available for qualification packages.
• Clear RFQ checklist (volume, CL, tolerance grade, temperature range) to accelerate quoting.

Engineering highlights

• Nominal frequency: 32.768 kHz
• Operating temperature: -40 to +85 °C
• Load capacitance (CL): 6 / 7 / 9 / 12.5 pF (custom on request)
• Frequency tolerance options: ±5 / ±10 / ±20 ppm (defined range depends on ordering option)
• ESR (max): 65 kΩ
• Drive level (max): 1.0 µW
• Shunt capacitance (typ.): 0.8 pF
• Aging (typ.): ±3 ppm (first year)

Production & procurement

• Package: 6.9 × 1.4 × 1.3 mm, 4-pad SMD (pick-and-place and reflow compatible)
• Compliance: RoHS & REACH documentation available with controlled revisions
• Quality support: CoC, lot traceability, and qualification support on request
• Automotive screening: AEC-Q200 availability can be evaluated based on your program needs

Load capacitance selection

Match the crystal’s CL to the effective load at the RTC/MCU pins. A common approximation is:

• Include internal capacitor settings (if your IC provides them) plus PCB stray capacitance.
• When uncertain, validate two adjacent CL options during EVT to reduce first-pass risk.

Start-up validation & ESR margin

• Check oscillation start-up across temperature corners and battery range.
• Review ESR margin against your IC’s negative resistance guideline.
• Confirm cold-start and wake-from-deep-sleep behavior on your final PCB stack-up.

Drive level control

• Keep drive within the specified maximum (1.0 µW) to protect long-term stability.
• Excess drive may accelerate aging and frequency drift.
• Follow MCU/RTC vendor guidance for oscillator gain or bias settings.

Practical accuracy levers

• Choose tighter tolerance options (e.g., ±5 ppm) if your time budget is strict.
• Validate frequency offset at your actual CL and PCB parasitic conditions.
• Consider firmware calibration/compensation in wide daily temperature swings.

Engineer note

A simplified model often used for tuning fork crystals is:

Use this model for first-order budgeting only; confirm with your system measurements and the latest datasheet.

Consumer & compact electronics

• Wearables and health devices requiring always-on timekeeping
• Smart home and IoT nodes with deep-sleep and periodic wake-up
• Portable data loggers and battery-powered controllers

Why these specs matter: controlled ESR and low max drive help keep start-up robust while preserving long-term stability in battery-operated products.

Telecom & narrow-layout systems

• Small mobile telecommunication devices and compact timing modules
• Systems with slim PCB design requirements and constrained keep-out areas
• Products requiring stable RTC behavior over -40 to +85°C

Why these specs matter: long-narrow 6914 footprint helps routing in dense layouts while keeping CL options aligned to common RTC oscillator networks.

Key mechanical data

Common ordering options

• Frequency: 32.768 kHz
• CL: 6 / 7 / 9 / 12.5 pF (custom on request)
• Tolerance grade: ±5 / ±10 / ±20 ppm (at 25°C)
• Temperature range: -20~70°C or -40~85°C (confirm by option)
• Screening / compliance pack: CoC, RoHS/REACH, lot traceability (on request)

Selection Path / Upgrade Options

• RTC Crystal Family (Industrial / Automotive / Medical)
• FCT-2M 32.768kHz Tuning Fork Crystal
• FCT-3M 32.768kHz Tuning Fork Crystal
• FCT-8M 32.768kHz Tuning Fork Crystal

If you share your RTC/MCU part number and target accuracy, FCom can recommend the best CL/tolerance combination and validate oscillator margin.

Datasheet

• Datasheet (PDF) — FCT-6M (6.9×1.4mm) 32.768kHz Tuning Fork Crystal

Certifications

• ISO9001 Certification
• ISO14001 Certification

Download

• Datasheet (PDF)
• 32.768kHz Crystal Portfolio
• Frequency Crystals Portfolio
• What Are Timing Devices?

What to verify in your design review

• Target CL option and the effective CL at your RTC pins
• ESR margin vs the RTC/MCU negative resistance guideline
• Drive level under worst-case gain settings and temperature
• Start-up behavior during cold-start and wake-from-sleep

If you share your MCU/RTC part number, oscillator network, and target accuracy budget, FCom can help review margins.

Procurement-friendly part description (example)

How do I choose CL for FCT-6M?

Select CL to match the effective load at the RTC/MCU pins: CL ≈ (C1×C2)/(C1+C2) + Cstray. Account for internal capacitors and PCB parasitics. When uncertain, validate two adjacent CL options during EVT.

What ensures reliable start-up?

Verify ESR margin vs your IC’s negative resistance guideline across temperature and supply corners. Keep traces short/symmetric and away from switching nodes. Confirm drive level stays below the specified maximum.

Is FCT-6M reflow compatible?

Yes—FCT-6M is supplied in an SMD package intended for pick-and-place and reflow soldering. For production release, confirm the latest datasheet and your assembly profile with FCom.

Can I request custom options?

Yes. Custom CL values, tighter tolerance, or project-specific reliability combinations may be supported upon review. Share your RTC/MCU, target accuracy budget, temperature range, and annual volume in your RFQ.

Do you publish pricing online? How do I get a quote?

Pricing is provided by RFQ because it depends on CL option, tolerance grade, screening, packaging, and annual volume. Send your checklist via email RFQ or the contact page for a formal quote.

What are typical MOQ and lead time?

MOQ and lead time depend on the exact option (CL/tolerance/temperature) and current production schedule. FCom supports sampling for evaluation and volume supply for production—share your target date and annual volume to confirm.

Can I request samples before mass production?

Yes. Samples are available for engineering validation. Include your RTC/MCU part number, target CL, and temperature range so we can recommend the best option for your oscillator margin.

What documents can you provide for qualification?

RoHS/REACH statements, CoC, lot traceability, and qualification support can be provided upon request. If you need specific test reports, list them in your RFQ.