32.768Khz Cylindrical Crystal Oscillator

32.768kHz Cylindrical Crystal Oscillator is arguably one of the most widely used components in electronics, serving as the essential time base for countless digital devices. This specific frequency is a power of two ($2^{15}$), which allows a simple chain of 15 flip-flops to divide the signal down to a perfectly accurate 1 Hz (one pulse per second). Encased in a distinctive metal cylinder, this quartz crystal is precision-cut to resonate exactly 32,768 times per second. Its reliable, low-frequency output and remarkably low power consumption make it the ideal choice for real-time clock (RTC) circuits, microcontroller timing, and any application where long-term, battery-powered timekeeping is critical. You can count on this crystal to provide the heart of accurate timing in your next project.

Key Features:

• Standard Timekeeping Frequency: Provides the industry-standard 32.768 kHz signal, which is easily divided down to 1 second.
• High Stability: Quartz crystal technology delivers excellent frequency stability over a wide range of operating conditions.
• Ultra-Low Power Operation: Requires minimal drive current, making it perfect for battery-operated devices with extended standby times.
• Compact Cylindrical Form: The small, hermetically sealed package protects the sensitive quartz element from environmental factors.
• Two-Pin Through-Hole Design: Offers easy integration into breadboards and standard printed circuit boards (PCBs).

Technical Specifications:

• Nominal Frequency: 32.768 kHz
• Frequency Tolerance: $\pm 20$ ppm (Parts Per Million) at $25^\circ \text{C}$ (Standard)
• Operating Temperature: -20°C to +70°C (Typical range)
• Load Capacitance (C_L): 12.5 pF (PicoFarads) or 9 pF (Common values)
• Series Resistance (R_S): 50 k$\Omega$ (Maximum)
• Drive Level: 1 $\mu$W (Maximum)

Mechanical Specifications:

• Package Type: Cylindrical (Tuning Fork)
• Mounting: Through-Hole (Axial Leads)
• Seal: Hermetically sealed metal case.

Dimensions:

• Cylinder Diameter: Typically 2.0 mm or 3.0 mm (Commonly referred to as $3 \times 8$ or $2 \times 6$)
• Cylinder Length: Typically 6.0 mm or 8.0 mm
• Lead Pitch (Spacing): Varies depending on mounting configuration, often bent to fit standard 0.1 inch spacing.

Pinout and Wiring:

• Pin 1 (XTAL1): Connects to the oscillator input pin of the driving IC (e.g., RTC chip or microcontroller).
• Pin 2 (XTAL2): Connects to the oscillator output pin of the driving IC.
• Wiring Note: You must place the crystal and its two associated loading capacitors (C_L) as close as possible to the IC pins to minimize noise and maintain stable oscillation. The crystal is non-polarized, so Pin 1 and Pin 2 are interchangeable.

Datasheet Reference:

• Download Generic 32.768 kHz Crystal Datasheet

Commonly Used in:

• Smart Watches and Wearables: Providing the precise, low-power timing base.
• Computer Motherboards: Serving as the clock source for BIOS and system time.
• Portable Medical Devices: Used in devices requiring accurate daily scheduling or event logging.

Applications:

• Real-Time Clock (RTC) Circuits: Supplying the frequency source for chips like the PCF8563 or DS1307.
• Microcontroller Sleep Modes: Keeping time while the main processor is in a deep, power-saving sleep state.
• Wireless Communication Synchronization: Providing a stable reference for low-power radio systems.

Equivalent Models:

• SMD 32.768 kHz Crystal: A surface-mount version used in high-density or automated assembly applications.
• Integrated RTC Modules: Modules like the DS3231 often have a compensated crystal built into the package.

Package Includes:

• 1 x 32.768kHz Cylindrical Crystal Oscillator