The **TOM-1545L-R** is a high-sensitivity **Omnidirectional Electret Condenser Microphone (ECM)**. These components are widely used in consumer electronics for audio recording, voice recognition, and telecommunications due to their small form factor and low power consumption. --- ### 1. Technical Specifications The following table summarizes the key electrical and physical characteristics of the TOM-1545L-R: | Parameter | Specification | | :--- | :--- | | **Type** | Electret Condenser Microphone | | **Directional Characteristic** | Omnidirectional (360° pickup) | | **Sensitivity** | -45dB ± 3dB (at 1kHz) | | **Operating Voltage** | 1.5V to 10V (Standard: 2.0V) | | **Current Consumption** | 0.5mA (Max) | | **Frequency Range** | 20Hz – 16,000Hz | | **S/N Ratio** | > 60dB | | **Output Impedance** | 2.2 kΩ | | **Dimensions** | Approx. 9.7mm (Diameter) x 4.5mm (Height) | --- ### 2. Internal Components & Structure The "L" in the part number typically refers to **Leads** (wires), and "R" often signifies **RoHS Compliance**. Internally, the device consists of: * **The Diaphragm:** A thin, metallized plastic film that vibrates when hit by sound waves. * **The Backplate:** A fixed plate that, together with the diaphragm, forms a capacitor. * **The Electret:** A material with a permanent static charge, eliminating the need for a high-voltage external power supply for the capacitor. * **Internal FET (Field Effect Transistor):** Because the impedance of the condenser is extremely high, a built-in JFET acts as an impedance converter/amplifier to make the signal usable for standard circuits. --- ### 3. Application Circuitry To use the TOM-1545L-R, you must provide a "Bias Voltage" through a load resistor. ```c VCC (2.0V - 10V) | [R_load: 2.2k ohm] | +----------[C_coupling: 1uF - 10uF]------> Audio Output | [MIC (+)] [ ] [MIC (-)] | GND ``` ### 4. Key Features 1. **Omnidirectional:** It picks up sound equally from all directions, making it ideal for ambient recording or devices where the user's position might change. 2. **High Sensitivity:** The -45dB rating allows it to capture faint sounds clearly. 3. **Stability:** It is designed to maintain performance across a wide temperature range and varying humidity levels. ---