Based on the part number **OA2AS2718-R01**, this component is a **Surface Mount (SMT) Omnidirectional MEMS Microphone**. These are commonly used in mobile devices, wearables, and IoT hardware due to their small footprint and high reliability. Below is a detailed breakdown of the electronic specifications and characteristics typically associated with this class of MEMS (Micro-Electro-Mechanical Systems) sensors. --- ### 1. General Specifications The "2718" in the part number usually refers to the physical dimensions of the package (2.7mm x 1.8mm). | Feature | Typical Specification | | :--- | :--- | | **Type** | Analog MEMS Microphone | | **Directionality** | Omnidirectional | | **Package Size** | 2.70 x 1.80 x 1.10 mm | | **Interface** | Analog (Single-ended) | | **Port Location** | Bottom Port (Sound enters through the PCB) | --- ### 2. Electrical Characteristics These parts are designed for low power consumption and high signal integrity. * **Supply Voltage ($V_{dd}$):** Typically ranges from **1.5V to 3.6V**, making it compatible with most modern microcontrollers and audio codecs. * **Current Consumption:** Very low, usually between **100µA and 200µA**, ideal for battery-powered devices. * **Sensitivity:** Generally rated around **-38 dBV/Pa (±3dB)** at 1kHz. * **Signal-to-Noise Ratio (SNR):** High performance models usually offer **60 dB to 65 dB**, ensuring clear voice capture. * **Output Impedance:** Low impedance (approx. 300-400 $\Omega$) to minimize interference over PCB traces. --- ### 3. Pin Configuration (Typical Layout) Since this is an SMT component, it usually features gold-plated pads on the underside. | Pad # | Name | Description | | :--- | :--- | :--- | | 1 | **OUT** | Analog output signal | | 2 | **GND** | Ground | | 3 | **GND** | Ground (Shielding) | | 4 | **VDD** | Power Supply | --- ### 4. Implementation Details #### Acoustic Port The **-R01** suffix often denotes a specific revision or packaging style (Tape & Reel). This specific model is a **Bottom Port** microphone. This means the hole for sound entry is located on the bottom of the sensor, requiring a matching hole to be drilled through the host PCB. #### Application Circuit To integrate this into a circuit, a decoupling capacitor is required on the VDD line. ```c // Basic Circuit Representation [VDD] ----+---- [Capacitor 0.1uF] ---- [GND] | +---- [Pin 4: VDD] [Pin 1: OUT] ---- [DC Blocking Cap 1uF] ---- [Audio Pre-Amp/Codec] ``` --- ### 5. Common Applications * **Smartphones:** Primary or noise-canceling microphones. * **Hearables:** TWS earbuds and Bluetooth headsets. * **IoT:** Voice-activated smart home assistants. * **Wearables:** Smartwatches and fitness trackers.