The **POM-3542L-R** is a high-performance electret condenser microphone (ECM) manufactured by **PUI Audio**. It is designed for high-sensitivity audio capture in compact electronic devices. --- ### 1. Key Technical Specifications The following table summarizes the primary electrical and physical characteristics of the component: | Parameter | Value / Specification | | :--- | :--- | | **Microphone Type** | Electret Condenser (ECM) | | **Directionality** | Omnidirectional | | **Sensitivity** | -42 ± 3 dB (0dB = 1V/Pa @ 1kHz) | | **Operating Voltage** | 1.5V to 10V (Standard: 2.0V) | | **Frequency Range** | 20 Hz ~ 20,000 Hz | | **Current Consumption** | 0.5 mA (Max) | | **Signal-to-Noise Ratio** | > 60 dB | | **Mounting Type** | Through-hole (Solder Pads/Pins) | | **Dimensions** | 6.0mm Diameter × 3.5mm Height | --- ### 2. Functional Components The "Electronic Parts" inside this microphone consist of several layers working together to convert sound into an electrical signal: 1. **The Diaphragm:** A thin, metallic-coated plastic film (usually Mylar) that vibrates when hit by sound waves. 2. **The Backplate:** A stationary plate that, together with the diaphragm, forms a capacitor (condenser). 3. **The Electret Material:** A permanent charge is embedded in the material (typically on the backplate), removing the need for an external high-voltage bias. 4. **Internal FET (Field Effect Transistor):** * Because the condenser element has a very high impedance, it cannot drive a circuit directly. * The POM-3542L-R contains an internal **JFET** that acts as an impedance converter/buffer. * It converts the high-impedance signal into a low-impedance signal usable by standard amplifiers. --- ### 3. Connection & Circuit Integration The device is a **two-terminal** microphone. To use it in a circuit, you must provide "Plug-in Power" using a pull-up resistor (load resistor). ```c Vcc (Positive Supply) | [R] Load Resistor (typically 2.2kΩ) | +----------[C] Output Coupling Capacitor (1uF - 10uF) ----> Audio Out | [POM-3542L-R] | GND (Ground) ``` --- ### 4. Common Applications * **Security Systems:** High sensitivity for room monitoring. * **Voice Recognition:** Clear frequency response for AI assistants. * **Consumer Electronics:** Laptops, tablets, and handheld recorders. * **Acoustic Sensors:** Measurement devices requiring an omnidirectional pickup pattern.