The **VCXO2EV-B12.288T3** is a high-performance Voltage Controlled Crystal Oscillator (VCXO). These components are critical in circuits requiring precise frequency control and synchronization, such as telecommunications and digital audio systems. --- ## 1. Technical Specifications The part number follows a specific nomenclature used by manufacturers (typically associated with brands like **Abracon** or **Raltron**). Below is a breakdown of the technical characteristics: | Parameter | Specification | Description | | :--- | :--- | :--- | | **Nominal Frequency** | 12.288 MHz | The base resonant frequency. | | **Output Type** | HCMOS / TTL | Standard digital output compatible with most MCUs. | | **Supply Voltage (Vdd)** | 3.3V (Typical) | The DC power required to run the oscillator. | | **Frequency Stability** | ±25 ppm to ±50 ppm | How much the frequency drifts over temperature. | | **Control Voltage (Vc)** | 0.3V to 3.0V | The analog voltage used to "pull" the frequency. | | **Pullability** | ±100 ppm (Typical) | The range the frequency can be adjusted. | | **Package Size** | 5.0 x 7.0 mm | Standard 6-pin SMD ceramic package. | --- ## 2. Core Electronic Components Inside the **VCXO2EV-B12.288T3**, several internal stages work together: 1. **Quartz Crystal Resonator:** A precision-cut quartz blank that vibrates at 12.288 MHz. 2. **Varactor Diode:** A voltage-variable capacitor. By changing the voltage on the "Control" pin, the capacitance changes, slightly shifting the crystal's resonant frequency. 3. **Oscillator IC:** An integrated circuit that provides the gain needed to maintain oscillation and buffers the output signal to a square wave (HCMOS). 4. **Bypass Capacitor:** Internal filtering to reduce noise on the power supply line. --- ## 3. Pin Configuration This device usually features a 6-pin footprint: | Pin # | Name | Function | | :--- | :--- | :--- | | 1 | **Vc** | Voltage Control (Adjusts frequency) | | 2 | **E/D** | Enable/Disable (Tristate function) | | 3 | **GND** | Ground | | 4 | **Output** | 12.288 MHz Square Wave | | 5 | **NC** | No Connection | | 6 | **Vdd** | Power Supply (+3.3V) | --- ## 4. Why 12.288 MHz? The specific frequency of **12.288 MHz** is a "magic number" in digital audio and communications. It is an exact multiple of standard audio sampling rates: * $48 \text{ kHz} \times 256 = 12.288 \text{ MHz}$ * $96 \text{ kHz} \times 128 = 12.288 \text{ MHz}$ It is commonly used as a Master Clock (MCLK) for **Audio DACs/ADCs** or within **Phase Locked Loops (PLLs)** to synchronize digital data streams. ---