The **ADR390BUJZ-R2** is a high-precision, low-power voltage reference integrated circuit manufactured by **Analog Devices**. It belongs to the ADR39x family, which is known for its "Micro-power" consumption and high stability. --- ### 1. Key Technical Specifications The following table summarizes the primary electrical characteristics of the ADR390 series. | Parameter | Specification | | :--- | :--- | | **Output Voltage ($V_{out}$)** | 2.048 V | | **Input Voltage Range** | 2.3 V to 15 V | | **Initial Accuracy** | ±4 mV (Grade B) | | **Temperature Coefficient** | 9 ppm/°C | | **Quiescent Current** | 120 µA (Maximum) | | **Operating Temperature** | -40°C to +125°C | | **Package Type** | TSOT-23-5 (UJ-5) | --- ### 2. Functional Description The ADR390 utilizes a patented **temperature drift curvature correction** technique. This allows the device to maintain a very stable output voltage even when the ambient temperature fluctuates significantly. #### Core Features: * **Low Dropout (LDO) Functionality:** It can operate with an input voltage as low as 300 mV above the output voltage. * **High Output Drive:** Despite its low power consumption, it can source up to 5 mA and sink up to 2 mA. * **No External Capacitor Required:** It is stable without an output capacitor, though one can be added to reduce high-frequency noise. --- ### 3. Pin Configuration (TSOT-23-5) | Pin Number | Name | Function | | :--- | :--- | :--- | | 1 | **DNC** | Do Not Connect (Internal use only) | | 2 | **GND** | Ground | | 3 | **DNC** | Do Not Connect | | 4 | **$V_{in}$** | Input Voltage Supply | | 5 | **$V_{out}$** | Reference Voltage Output | --- ### 4. Common Applications Due to its precision and low power footprint, the ADR390BUJZ-R2 is commonly used in: 1. **Battery-Powered Instrumentation:** Handheld meters and portable diagnostic tools. 2. **ADC/DAC References:** Providing a stable baseline for 12-bit to 16-bit converters. 3. **Precision Process Control:** Industrial sensors and 4-20mA loop transmitters. 4. **Automotive Systems:** High-temperature stability makes it suitable for engine control units. ---