The **MLV-1-R/E** is a specific model of a **Miniature Low Pressure Sensor** manufactured by All Sensors Corporation. It is designed for precision measurements of very low pressures using a MEMS (Micro-Electro-Mechanical Systems) piezoresistive technology. --- ### 1. Key Technical Specifications The "MLV" series is known for its "Millivolt" output and low voltage requirements. | Parameter | Specification | | :--- | :--- | | **Pressure Range** | 1 inH2O (Inches of Water Column) | | **Output Type** | Ratiometric Millivolt (Unamplified) | | **Operating Voltage** | 1.0 to 12.0 VDC (Nominal: 5V) | | **Pressure Type** | Differential / Gage | | **Technology** | Piezoresistive Silicon (MEMS) | | **Package Style** | E-Series (Leadless/Through-hole hybrid) | --- ### 2. Internal Electronic Structure The sensor operates on a **Wheatstone Bridge** circuit configuration. This is the fundamental electronic part of the device: 1. **Piezoresistive Die:** The core is a micromachined silicon diaphragm with four ion-implanted resistors. 2. **The Bridge:** When pressure is applied, the diaphragm flexes, changing the resistance of the bridge. This produces a differential voltage output proportional to the pressure. 3. **Coherent Design:** The MLV series uses a proprietary "CoBeam" technology which reduces package stress and improves susceptibility to shock and vibration. --- ### 3. Connection and Pinout The MLV-1-R/E typically features a 4-pin interface. Because it is an unamplified sensor, it requires an external instrumentation amplifier (like an AD620 or an ADC with a built-in PGA) to be read by a microcontroller. | Pin Number | Function | Description | | :--- | :--- | :--- | | **1** | **GND** | Supply Ground | | **2** | **+Vout** | Positive Output Signal | | **3** | **Vs** | Supply Voltage (Input) | | **4** | **-Vout** | Negative Output Signal | --- ### 4. Critical Design Considerations * **Unamplified Signal:** The output is in the millivolt range (e.g., 5-20mV full scale). Noise shielding is critical. * **Excitation:** While it can handle up to 12V, higher voltages increase self-heating, which can lead to measurement drift. * **Media Compatibility:** These sensors are generally designed for non-corrosive, non-ionic working fluids such as air and dry gases. ---