The **ASX03304-SM-R** is a specialized surface-mount (SMD) audio transducer, specifically a high-quality **micro-speaker** manufactured by PUI Audio. It is designed for compact electronic devices where space is at a premium but clear sound reproduction is required. --- ### ## Technical Specifications Below are the primary electrical and physical characteristics of the ASX03304-SM-R: | Parameter | Specification | | :--- | :--- | | **Component Type** | Dynamic Speaker (Moving Coil) | | **Impedance** | 4 Ohms ± 15% | | **Rated Power** | 0.3 Watts | | **Max Power** | 0.5 Watts | | **Sound Pressure Level (SPL)** | 80 dB @ 0.1W / 0.1M | | **Frequency Range** | 500 Hz ~ 20,000 Hz | | **Resonant Frequency (Fo)** | 850 Hz ± 20% | | **Mounting Type** | Surface Mount (SMD) | | **Dimensions** | 13mm x 13mm x 4mm | --- ### ## Key Electronic Features #### 1. Low Impedance (4Ω) The 4-ohm impedance allows the speaker to draw more current at lower voltages. This makes it ideal for **battery-powered devices** (like those using a 3.7V Li-Po battery) where a high-output volume is needed without a high-voltage rail. #### 2. SMD Construction Unlike traditional speakers with wires or pins, this part is designed for **Automated Pick-and-Place** assembly. It features gold-plated solder pads on the bottom, allowing it to be reflow soldered directly onto a PCB, reducing assembly costs and improving mechanical reliability. #### 3. Neodymium Magnet The "R" in the series often denotes the use of high-energy magnets (usually Neodymium). This allows the speaker to maintain a slim profile (4mm height) while providing enough magnetic flux to drive the diaphragm efficiently. #### 4. Wide Frequency Response While it is a "micro" speaker, its range extends up to 20kHz. This ensures that high-frequency alerts, chimes, and even basic voice prompts sound crisp rather than muffled. --- ### ## Typical Applications * **IoT Devices:** Smart home sensors and hubs. * **Handheld Medical Tools:** Glucose monitors or digital thermometers. * **Wearables:** Advanced fitness trackers or smartwatches. * **Security Products:** Keypads and entry systems. --- ### ## Design Considerations * **Enclosure:** To achieve the best bass response and prevent phase cancellation, this speaker should be mounted in a sealed or vented back-enclosure within the device housing. * **Driving Circuit:** Since it is a 4-ohm load, ensure your audio amplifier (Class D or Class AB) is rated to handle low-impedance loads to prevent overheating the driver IC.