## KPY51-R Pressure Sensor Overview The **KPY51-R** is a silicon-based piezoresistive pressure sensor known for its high sensitivity and reliability. It is primarily used in industrial and automotive applications to measure absolute pressure. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Sensor Type** | Piezoresistive Silicon | | **Pressure Type** | Absolute Pressure | | **Operating Pressure Range** | 0 to 2.0 bar (approx. 200 kPa) | | **Supply Voltage (Nominal)** | 5V to 10V DC | | **Bridge Resistance** | ~4.0 kΩ to 8.0 kΩ | | **Full Scale Output** | ~80 mV to 160 mV (at 5V supply) | | **Linearity Error** | < 0.2% | | **Operating Temperature** | -40°C to +125°C | --- ### 2. Functional Characteristics * **Piezoresistive Bridge:** The sensor utilizes a Wheatstone bridge circuit integrated onto a silicon chip. When pressure is applied, the silicon diaphragm deforms, changing the resistance and producing a differential voltage. * **Media Compatibility:** It is generally designed for use with non-corrosive gases and liquids. * **R-Variant Feature:** The "R" suffix often indicates specific package enhancements or calibration features tailored for robust environmental resistance. --- ### 3. Pinout and Connection While specific TO-package configurations may vary, the standard connection logic for the KPY series follows this structure: | Pin Number | Function | Description | | :--- | :--- | :--- | | **1** | - Vout | Negative Differential Output | | **2** | + Vin | Positive Supply Voltage | | **3** | + Vout | Positive Differential Output | | **4** | - Vin | Ground / Negative Supply | --- ### 4. Typical Applications 1. **Automotive:** Manifold Absolute Pressure (MAP) sensing and tire pressure monitoring. 2. **Industrial:** Pneumatic controls, liquid level measurement, and leak detection. 3. **Medical:** Blood pressure monitors and respiratory equipment. 4. **Weather Stations:** Barometric pressure sensing. --- ### 5. Implementation Note Because the output signal is in **millivolts**, it is too small for direct reading by most microcontrollers (like Arduino or ESP32). An **Instrumentation Amplifier** (e.g., AD620 or INA125) is required to boost the signal to a 0-5V range.