The **MHO+21FAD-R** is a high-performance, programmable crystal oscillator (SPXO) manufactured by **MtronPTI**. This specific part belongs to the MHO series, which is widely used in applications requiring high reliability, compact sizing, and precise frequency control. --- ### 1. General Specifications The part number follows a specific nomenclature that defines its electronic characteristics: | Feature | Specification | | :--- | :--- | | **Output Type** | HCMOS / TTL | | **Package Size** | 5.0 x 7.0 mm (Ceramic SMD) | | **Operating Voltage** | 3.3V DC | | **Frequency Range** | Typically 1.5 MHz to 170.0 MHz | | **Operating Temperature** | -40°C to +85°C (Industrial Grade) | | **Termination** | RoHS Compliant / Lead-Free | --- ### 2. Key Electronic Components & Internal Logic Inside the ceramic package, the MHO+21FAD-R consists of several integrated layers: * **Quartz Crystal Resonator:** The heart of the part, providing the mechanical resonance that determines the frequency. * **Oscillator IC (ASIC):** An integrated circuit that drives the crystal and converts the mechanical vibrations into an electrical signal. * **Tristate Function (Pin 1):** This allows the output to be placed in a high-impedance state, effectively "turning off" the output signal without powering down the entire device. This is crucial for bus-oriented designs. * **Bypass Capacitor Requirement:** While not inside the part, it is electronically required to place a **0.01µF to 0.1µF capacitor** between the Vdd and Ground pins to filter high-frequency noise. --- ### 3. Pin Configuration (4-Pad Layout) The device uses a standard 5x7mm footprint with the following pin assignment: | Pin Number | Function | Description | | :--- | :--- | :--- | | **1** | E/D (Enable/Disable) | High or Floating = Output Active; Low = High Impedance | | **2** | GND | Case Ground / System Ground | | **3** | Output | HCMOS / TTL Clock Signal | | **4** | Vdd | Positive Supply Voltage (+3.3V) | --- ### 4. Technical Performance Table | Parameter | Value | Unit | | :--- | :--- | :--- | | **Frequency Stability** | ±100 ppm (Standard) | ppm | | **Input Current** | 15 - 45 (Frequency dependent) | mA | | **Rise/Fall Time** | 6.0 (max) | ns | | **Duty Cycle** | 45% to 55% | % | | **Output Load** | 15 | pF | --- ### 5. Application Use-Cases Electronic engineers typically specify the **MHO+21FAD-R** for: * **Embedded Systems:** Providing the master clock for Microcontrollers (MCUs) or FPGAs. * **Networking:** Clocking for Ethernet switches and routers. * **Industrial Controls:** Reliability in harsh temperature environments (-40°C to +85°C). * **Consumer Electronics:** High-speed data processing units.