### REF02HS: Precision Voltage Reference The **REF02HS** is a precision 5.0V voltage reference integrated circuit. It is widely used in applications requiring a stable and accurate voltage source for Analog-to-Digital Converters (ADCs) and Digital-to-Analog Converters (DACs). --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Output Voltage ($V_{out}$)** | 5.0V | | **Input Voltage Range** | 7.0V to 40.0V | | **Temperature Drift** | 8.5 ppm/°C (Max) | | **Output Adjustment Range** | ±3% (using TRIM pin) | | **Output Current** | 10 mA | | **Package Type** | SOIC-8 (Surface Mount) | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Functional Pins Description The REF02HS typically comes in an 8-pin SOIC package. Below is the pinout functionality: 1. **TEMP (Pin 3):** Provides a voltage output proportional to the chip temperature. This can be used for temperature sensing or compensation. 2. **TRIM (Pin 5):** Allows the user to fine-tune the 5.0V output using a potentiometer. 3. **Vout (Pin 6):** The stabilized 5.0V output terminal. 4. **Vin (Pin 2):** The unregulated input supply voltage. 5. **GND (Pin 4):** Ground reference. --- ### 3. Core Features & Benefits * **High Stability:** The device maintains a very low drift over a wide temperature range, ensuring that precision measurements do not "float." * **Low Noise:** It produces minimal electronic noise, which is critical for high-resolution (12-bit or higher) data conversion systems. * **Short-Circuit Protection:** The output is protected against accidental shorts to ground. * **Built-in Temperature Transducer:** The "TEMP" pin outputs approximately 2.1 mV per degree Kelvin, allowing the circuit to monitor its own thermal environment. --- ### 4. Typical Application Circuit To use the REF02HS, a basic circuit requires very few external components. ```c // Connection Diagram: // 1. Connect Input (7V-40V) to Pin 2 (Vin). // 2. Connect Pin 4 to Ground. // 3. Take 5.0V output from Pin 6 (Vout). // 4. (Optional) 0.1uF Capacitor between Vin and GND for decoupling. // 5. (Optional) 10k Potentiometer between Pin 6 and Pin 4, // with the wiper connected to Pin 5 (TRIM) for calibration. ``` --- ### 5. Common Use Cases * **Precision Data Acquisition:** Providing the reference level for ADCs. * **Calibration Standards:** Used in hand-held instruments for voltage verification. * **Power Supplies:** Serving as the reference for linear regulators. * **Sensors:** Powering bridge sensors that require a highly stable excitation voltage.