## Overview of POM-3546P-R The **POM-3546P-R** is a high-sensitivity, omnidirectional **electret condenser microphone (ECM)** capsule. It is designed for picking up sound from all directions and converting acoustic energy into electrical signals. It is commonly used in telecommunications, voice recording devices, and consumer electronics. --- ### Technical Specifications The following table outlines the key electrical and physical parameters of the POM-3546P-R: | Parameter | Specification | | :--- | :--- | | **Directivity** | Omnidirectional | | **Sensitivity** | -46 ± 3 dB (0dB=1V/Pa, 1kHz) | | **Operating Voltage** | 1.5V to 10V (Standard: 2.0V) | | **Current Consumption** | Max 0.5 mA | | **Frequency Range** | 20 Hz – 20,000 Hz | | **Signal-to-Noise Ratio** | > 60 dB | | **Impedance** | 2.2 kΩ (Max) | | **Dimensions** | 6.0 mm (Diameter) x 3.5 mm (Height) | | **Connection Type** | Through-hole (Solder Pins) | --- ### Internal Components & Operation The POM-3546P-R consists of several critical electronic parts housed within its metallic casing: 1. **Vibrating Diaphragm:** A thin plastic film (usually Mylar) coated with a conductive gold or nickel layer. It reacts to sound pressure waves. 2. **Back Plate:** A stationary plate that, together with the diaphragm, forms a capacitor. In electret models, this plate (or the diaphragm) holds a permanent electrostatic charge. 3. **FET (Field Effect Transistor):** Because the impedance of the condenser element is extremely high, an internal FET acts as an **impedance converter** and buffer. It translates the high-impedance signal to a lower impedance that can be used by standard audio circuits. 4. **Metal Housing:** Acts as a Faraday shield to protect the sensitive internal signal from Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI). --- ### Typical Application Circuit To use the POM-3546P-R, you must provide "Plug-in Power" or a bias voltage through a resistor. ```mermaid [VCC (2.0V)] | [RL (2.2kΩ Resistor)] | +----[ Output Coupling Capacitor (1uF) ]----> Audio Out | [POM-3546P-R (+)] | [POM-3546P-R (-)] | [GND] ``` ### Key Features * **Small Form Factor:** The 6mm diameter makes it ideal for compact PCB designs. * **Wide Frequency Response:** Covers the full human hearing range, making it suitable for high-fidelity voice capture. * **RoHS Compliant:** Built using environmentally friendly materials.