The **MAH28TCA-R** is a high-performance, ultra-compact piezo electronic buzzer/transducer designed for applications requiring high sound pressure levels (SPL) in a small footprint. It is commonly used in medical devices, industrial alarms, and security systems. --- ### 1. Technical Specifications The following table highlights the core electronic and physical characteristics of the component: | Parameter | Specification | | :--- | :--- | | **Type** | Piezoelectric Transducer | | **Operating Voltage** | 1.0 ~ 30.0 Vp-p | | **Rated Voltage** | 10.0 Vp-p | | **Current Consumption** | Max 10.0 mA (at rated voltage/frequency) | | **Sound Pressure Level (SPL)** | Min 100 dB @ 10cm / 10Vp-p | | **Resonant Frequency** | 2,800 ± 500 Hz | | **Operating Temperature** | -40°C to +85°C | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Key Electronic Features #### A. Piezoelectric Element Unlike electromagnetic buzzers that use a coil and magnet, the MAH28TCA-R utilizes a **piezoelectric ceramic disk**. - **Advantage:** It consumes significantly less power and generates no electromagnetic interference (EMI). - **Drive Requirement:** It requires an external oscillating circuit (square wave) to produce sound. It is a *transducer*, not an *indicator*. #### B. High SPL Performance The "100 dB" rating is exceptionally high for a surface-mount component. This is achieved through: - Optimized acoustic cavity design within the plastic housing. - High-efficiency ceramic materials that maximize displacement per volt. #### C. Environmental Durability The part is designed with a high temperature resistance (up to +85°C), making it compatible with **Lead-Free Reflow Soldering** processes common in modern PCB assembly. --- ### 3. Application Circuitry To operate the MAH28TCA-R, you typically need a driving circuit. A common method is using a **NPN Transistor switch** or a **Push-Pull (Bridge)** circuit to maximize volume. ```c // Example logic for driving the buzzer (Pseudo-code) void playTone(int frequency, int duration) { long delayValue = 1000000 / frequency / 2; // Calculate half-period for (long i = 0; i < duration * 1000L; i += delayValue * 2) { digitalWrite(BUZZER_PIN, HIGH); delayMicroseconds(delayValue); digitalWrite(BUZZER_PIN, LOW); delayMicroseconds(delayValue); } } ``` --- ### 4. Comparison: Transducer vs. Indicator It is vital to distinguish this part from a "Plug-and-Play" buzzer: * **MAH28TCA-R (Transducer):** Needs an external AC/Square wave signal. You can change the pitch by changing the frequency. * **Indicator (Internal Circuit):** Needs only DC voltage. It plays a fixed tone and cannot be adjusted.