The **FTS-54-R** typically refers to a high-precision, low-profile **tuning fork crystal (Quartz Crystal Unit)** commonly used in electronic timing circuits. These components are essential for generating stable clock frequencies in microcontrollers and real-time clocks (RTCs). ### 1. Key Technical Specifications The "54" in the series usually denotes the package size (e.g., 5.0 x 4.0 mm), and the "R" often signifies compliance with RoHS standards or specific tape-and-reel packaging. | Parameter | Typical Value / Range | | :--- | :--- | | **Frequency Range** | 32.768 kHz (Standard for RTC) | | **Frequency Tolerance** | ±10 ppm to ±50 ppm | | **Load Capacitance ($C_L$)** | 6pF, 7pF, 9pF, or 12.5pF | | **Operating Temperature** | -40°C to +85°C (Industrial Grade) | | **Equivalent Series Resistance (ESR)** | 50 kΩ to 80 kΩ Max | | **Drive Level** | 0.1 µW to 1.0 µW | --- ### 2. Functional Electronic Anatomy The FTS-54-R operates based on the **Piezoelectric Effect**. Inside the protective metal or ceramic casing, there is a quartz crystal cut into a "tuning fork" shape. * **Electrodes:** Thin layers of metal (usually gold or silver) deposited on the quartz arms. When an electric field is applied, the quartz physically deforms. * **Vibration Mode:** It vibrates at a specific resonant frequency. For the 54 series, this is almost exclusively used for low-frequency timing. * **Package Construction:** Usually a **Seam Sealed** package. This provides a vacuum-tight environment to prevent moisture from affecting the frequency stability. --- ### 3. Application Circuitry To use the FTS-54-R in a circuit, it is paired with an internal oscillator circuit (usually a Pierce Oscillator) inside a microcontroller. #### Typical Wiring Diagram Logic: ```text [ Microcontroller ] / \ OSC_IN (Pin 1) OSC_OUT (Pin 2) | | +-------[ Crystal ]----+ | | [C1] [C2] <-- Load Capacitors | | (GND) (GND) ``` ### 4. Why use this specific part? 1. **Low Power Consumption:** Tuning fork crystals require very little energy to maintain oscillation, making them ideal for battery-powered devices. 2. **Stability:** They offer much higher accuracy than internal RC oscillators found in chips. 3. **Space Efficiency:** The SMD (Surface Mount Device) profile allows for thin PCB designs in wearables or IoT sensors. ---