## ROM-2235L-HD-R Technical Overview The **ROM-2235L-HD-R** is a high-sensitivity, omnidirectional Electret Condenser Microphone (ECM) component. It is designed for picking up acoustic signals and converting them into electrical signals, commonly used in telecommunications, security systems, and consumer electronics. --- ### 1. Key Technical Specifications | Parameter | Value | | :--- | :--- | | **Type** | Electret Condenser Microphone (ECM) | | **Directivity** | Omnidirectional (360° pickup) | | **Sensitivity** | -35 ± 3 dB (0dB = 1V/Pa, 1kHz) | | **Operating Voltage** | 1.0V to 10.0V DC (Standard 2.0V) | | **Current Consumption** | 0.5 mA (Maximum) | | **Frequency Range** | 50 Hz – 20,000 Hz | | **S/N Ratio** | > 58 dB | | **Impedance** | Less than 2.2 kΩ | | **Dimensions** | Approx. 6.0mm (Diameter) x 2.2mm (Height) | --- ### 2. Physical Construction and Pins The device is housed in a compact aluminum cylindrical canister. As a "Lead" type (indicated by the 'L' in the part number), it typically features solder pads or pins for PCB mounting. * **Positive Terminal (+):** Carries the audio signal and DC bias. * **Negative Terminal (-):** Connected to the metal case (Ground). --- ### 3. Application Circuit Example To function correctly, an ECM requires a "bias" circuit to power the internal JFET. Below is a standard configuration: ```text VCC (2.0V) | [ R1: Load Resistor 2.2k ] | +----------[ C1: DC Blocking Cap ]-----> Audio Out | [ ROM-2235L-HD-R ] | GND ``` ### 4. Features and Performance * **High Sensitivity:** The "-35dB" rating makes it highly effective for picking up faint sounds or for use in devices where the microphone is recessed. * **Small Form Factor:** The 2.2mm height (Low Profile) allows it to fit into slim smartphones, tablets, or wearable devices. * **Stability:** Designed to maintain consistent sensitivity across a wide temperature range. ---