The **KPY62-RK** is a high-precision silicon pressure sensor manufactured by Siemens (and later Infineon). It belongs to the KPY series, which utilizes the **piezoresistive effect** to measure relative or absolute pressure. --- ### 1. Technical Specifications The following table summarizes the key electronic and physical characteristics of the KPY62-RK: | Parameter | Typical Value | Unit | | :--- | :--- | :--- | | **Nominal Pressure Range** | 0 to 10 | bar | | **Sensor Type** | Piezoresistive | - | | **Supply Voltage (Nominal)** | 5.0 | V (DC) | | **Bridge Resistance** | 4.0 to 8.0 | kΩ | | **Full Scale Output Voltage** | 60 - 140 | mV | | **Operating Temperature** | -40 to +125 | °C | | **Linearity Error** | < 0.5 | % FS | --- ### 2. Operating Principle The sensor consists of a micromachined silicon diaphragm with integrated strain gauges (resistors) arranged in a **Wheatstone Bridge** configuration. 1. **Pressure Application:** When pressure is applied to the diaphragm, it deflects slightly. 2. **Resistance Change:** This mechanical stress changes the electrical resistance of the integrated resistors (Piezoresistive effect). 3. **Voltage Output:** The bridge becomes unbalanced, producing a differential output voltage ($V_{OUT}$) that is directly proportional to the applied pressure and the input supply voltage. --- ### 3. Key Electronic Features * **High Sensitivity:** Small changes in pressure result in measurable millivolt changes. * **Temperature Compensation:** Because silicon resistors are sensitive to temperature, these sensors usually require external or internal compensation circuits to maintain accuracy across the -40°C to +125°C range. * **Ratiometric Output:** The output signal is dependent on the supply voltage. If the supply voltage fluctuates, the output scale shifts proportionally. * **Durability:** The "RK" designation typically refers to a specific housing or calibration grade suitable for industrial environments. --- ### 4. Typical Application Circuit To use the KPY62-RK in an electronic system, you generally need an **Instrumentation Amplifier** (such as an AD620 or an INA126) because the raw output signal is in millivolts and cannot be read directly by most Microcontroller ADCs. ```cpp // Logic flow for interfacing with an MCU 1. Supply 5V to the Bridge Input. 2. Connect Bridge Output (+) and (-) to an Instrumentation Amplifier. 3. Set Amplifier Gain (e.g., Gain = 40) to bring 100mV up to 4V. 4. Connect Amplifier Output to Microcontroller ADC pin. 5. Apply Calibration formula: Pressure = (Voltage - Offset) * Scale_Factor. ```