## Overview of the REF02C The **REF02C** is a precision voltage reference integrated circuit that provides a stable **+5.0V** output from a wide range of input voltages. It is widely used in analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and precision instrumentation due to its low drift and high stability. --- ### 1. Key Technical Specifications The "C" suffix typically denotes the commercial temperature range version of the REF02 series. Below are the primary technical parameters: | Parameter | Value / Range | | :--- | :--- | | **Output Voltage** | +5.0V DC | | **Input Voltage Range** | 7V to 40V | | **Output Adjustment Range** | ±3% (via Trim pin) | | **Temperature Coefficient** | 8.5 ppm/°C to 25 ppm/°C (model dependent) | | **Output Current** | 10 mA (typical) | | **Quiescent Current** | 1.4 mA (max) | | **Temperature Range** | 0°C to +70°C | --- ### 2. Pin Configuration and Functions The REF02C is most commonly found in the **8-pin SOIC** or **PDIP** packages. | Pin Number | Name | Function | | :--- | :--- | :--- | | 2 | **VIN** | Input voltage (7V to 40V). | | 3 | **TEMP** | Output voltage proportional to temperature (approx. 2.1mV/°K). | | 4 | **GND** | System ground. | | 5 | **TRIM** | Allows fine-tuning of the 5V output using a potentiometer. | | 6 | **VOUT** | Regulated +5.0V output. | --- ### 3. Distinctive Features #### A. Temperature Sensing (TEMP Pin) One of the unique features of the REF02C is the **TEMP pin**. The voltage at this pin is directly proportional to the absolute temperature of the chip. This allows the device to double as a temperature transducer for system thermal monitoring. #### B. Output Trimming By connecting a potentiometer between the Output (Pin 6), Trim (Pin 5), and Ground (Pin 4), users can calibrate the output voltage to exactly 5.000V, compensating for system tolerances. #### C. Low Noise The device is designed for high-resolution systems, featuring very low noise (approx. 10 $\mu$V p-p in the 0.1Hz to 10Hz range), which prevents jitter in sensitive measurement circuits. --- ### 4. Basic Application Circuit To use the REF02C in a standard configuration, minimal external components are required. ```markdown +7V to +40V | [ 0.1uF Cap ] (Optional bypass) | +-----+-----+ | Pin 2: VIN| | | +5.0V Stable Output | REF02C |----------o-----> | | | | Pin 4: GND| [ 1uF - 10uF Cap ] (Load stability) +-----+-----+ | | GND GND ``` ---