The **MA24FAD-R** is a high-performance, compact **Surface Mount (SMD) Quartz Crystal Unit** primarily manufactured by companies like *NDK (Nihon Dempa Kogyo)*. It is designed for applications requiring high stability and a small footprint. --- ### 1. Key Technical Specifications The part belongs to the MA series of crystals. Below are the typical parameters for this component: | Parameter | Typical Value | | :--- | :--- | | **Frequency Range** | 24.000 MHz (Commonly used) | | **Package Size** | 2.0 x 1.6 mm (2016 size) | | **Load Capacitance ($C_L$)** | 8pF to 12pF (depending on sub-variant) | | **Frequency Tolerance** | ±10 ppm to ±30 ppm | | **Operating Temperature** | -40°C to +85°C | | **Equivalent Series Resistance (ESR)** | < 60 Ω | | **Drive Level** | 10µW to 100µW | --- ### 2. Internal Construction & Operation The MA24FAD-R functions as a **Passive Resonator**. It utilizes the piezoelectric effect of synthetic quartz to provide a precise frequency reference for microcontrollers and wireless ICs. * **AT-Cut Crystal:** It uses an AT-cut quartz blank, which provides excellent temperature stability. * **Ceramic Package:** The "R" in the suffix often denotes the packaging style (Tape and Reel) and the use of a seam-welded ceramic lid for hermetic sealing. * **Four Pads:** Although it is a 2-terminal resonator, the package usually has 4 pads (Pads 1 and 3 are for the crystal connection, while 2 and 4 are grounded to the metal lid to reduce EMI). --- ### 3. Application Use Cases Due to its small 2016 form factor and stability, it is widely found in: 1. **Bluetooth/BLE Modules:** Providing the clock source for 2.4GHz radio synchronization. 2. **IoT Devices:** Low power consumption and space-saving design. 3. **Mobile Electronics:** Smartphones and wearables. 4. **USB Interfaces:** High-speed data timing. --- ### 4. Layout Recommendation (Circuit Design) When integrating this part into a PCB, follow these guidelines: ```c // Design Rule Check (DRC) for Crystal Layout: 1. Keep the crystal as close to the MCU "OSC_IN" and "OSC_OUT" pins as possible. 2. Ensure a solid ground plane directly beneath the crystal. 3. Keep high-speed signal traces (PWM, SPI) away from the crystal traces to avoid interference. 4. Match the load capacitors (C1, C2) according to the formula: CL = (C1 * C2) / (C1 + C2) + C_stray. ```