The **MH22TAD-R** is an electronic component primarily classified as a **Magnetic Hall Effect Sensor** (specifically a latch-type digital sensor). These parts are commonly used in automotive and industrial applications for position sensing and speed detection. --- ### 1. Key Technical Specifications The following table highlights the critical electrical characteristics of the MH22TAD-R: | Parameter | Specification | Details | | :--- | :--- | :--- | | **Sensor Type** | Hall Effect Latch | Detects magnetic poles (North/South) | | **Supply Voltage ($V_{CC}$)** | 3.0V to 24V | Wide operating range | | **Output Type** | Open Drain | Requires an external pull-up resistor | | **Operating Temperature** | -40°C to +125°C | Industrial/Automotive grade | | **Package Type** | SOT-23 | Small Surface Mount Device (SMD) | | **Magnetic Sensitivity** | High | Precise switching points | --- ### 2. Functional Description The MH22TAD-R operates based on the **Hall Effect** principle. When a magnetic field of sufficient density (flux) is applied to the sensor, it changes its output state. * **Latching Behavior:** As a "Latch" type, it stays in a specific state (ON or OFF) even after the magnetic field is removed, until a field of the **opposite polarity** is applied. * **South Pole:** Typically turns the output **ON** (Low voltage). * **North Pole:** Typically turns the output **OFF** (High impedance/High voltage via pull-up). --- ### 3. Typical Application Circuit Because the output is an **Open Drain (NPN)** configuration, it must be wired with a pull-up resistor to the microcontroller's logic level. ```cpp // Schematic representation logic [VCC] ----+----------- (3V - 24V) | [10k Pull-up Resistor] | [OUT] ----+----------- To MCU Input Pin | [GND] ----------------- Ground ``` --- ### 4. Common Use Cases 1. **Brushless DC (BLDC) Motors:** Used to detect the rotor position for commutation. 2. **Speedometers:** Counting rotations of a wheel or gear embedded with magnets. 3. **Proximity Switching:** Non-contact switches in automotive door locks or power windows. 4. **Flow Meters:** Measuring the rotation of an internal turbine.