The **MH43FBD-R** is a specific type of **Hall Effect Sensor IC**, typically manufactured by companies like Magne-Halt or similar semiconductor firms specializing in magnetic sensing. It is primarily used for position sensing, speed detection, and non-contact switching. --- ### 1. Technical Specifications The following table summarizes the key electrical and physical characteristics of the MH43FBD-R: | Characteristic | Specification | | :--- | :--- | | **Sensor Type** | Hall Effect (Bipolar Switch) | | **Supply Voltage ($V_{CC}$)** | 3.8V to 28V DC | | **Output Type** | Open Collector (NPN) | | **Magnetic Sensitivity** | High (Bipolar) | | **Operating Temperature** | -40°C to +125°C | | **Package Type** | SOT-23 (Surface Mount) or TO-92S (Through-hole) | | **Output Current ($I_{out}$)** | 25mA to 50mA | --- ### 2. Functional Description The MH43FBD-R operates based on the Hall Effect principle, converting magnetic field density into an electrical signal. * **Bipolar Switching:** This device is "Bipolar," meaning it requires a **South pole** magnetic field to turn the output ON and a **North pole** magnetic field to turn the output OFF. * **Open Collector Output:** The sensor acts like a switch to ground. To interface with a microcontroller (like Arduino or ESP32), a **pull-up resistor** (typically 1kΩ to 10kΩ) must be connected between the Output pin and $V_{CC}$. * **Built-in Protection:** It usually includes a reverse battery protection diode and an internal voltage regulator to handle wide supply ranges. --- ### 3. Pin Configuration For the common SOT-23 package, the pinout is generally as follows: 1. **VDD ($V_{CC}$):** Power Supply Input. 2. **OUT:** Open Collector Output. 3. **GND:** Ground. --- ### 4. Common Applications * **BLDC Motors:** Used for rotor position sensing to time electronic commutation. * **Speedometers:** Detecting the rotation of gears or magnets in automotive and industrial machinery. * **Proximity Switching:** Non-contact limit switches in CNC machines or 3D printers. * **Flow Meters:** Measuring the rotation of an internal turbine containing small magnets. ---