### Overview of ADR391BUJZ-R2 The **ADR391BUJZ-R2** is a precision micropower, low dropout (LDO) voltage reference. It belongs to the ADR39x family of devices, which are known for their stable performance and extremely low power consumption, making them ideal for battery-powered applications. --- ### Technical Specifications | Parameter | Specification | |:---|:---| | **Output Voltage ($V_{out}$)** | 2.500 V | | **Input Voltage Range** | 2.8 V to 15 V | | **Initial Accuracy** | ±5 mV (Grade B) | | **Temperature Coefficient** | 9 ppm/°C (Grade B) | | **Supply Current** | 120 µA (Maximum) | | **Output Current Drive** | 5 mA | | **Package Type** | TSOT-23-5 (UJ-5) | | **Operating Temperature** | -40°C to +125°C | --- ### Key Electronic Features 1. **Low Dropout (LDO):** The device can maintain a stable output even when the input voltage is only slightly higher than the output (dropout voltage is typically 300 mV at 5 mA load). 2. **Micropower Consumption:** With a maximum quiescent current of 120 µA, it minimizes power drain in portable systems. 3. **No External Capacitor Required:** It is designed to be stable without an external output capacitor, though one can be added to improve transient response. 4. **Shutdown Pin:** It includes a shutdown mode to further reduce power consumption when the reference is not needed. --- ### Pin Configuration (TSOT-23-5) | Pin No. | Name | Description | |:---:|:---|:---| | 1 | **$DNC$** | Do Not Connect internally. | | 2 | **$GND$** | Ground reference. | | 3 | **$SHDN$** | Shutdown control (Active Low). | | 4 | **$V_{in}$** | Input Voltage Supply. | | 5 | **$V_{out}$** | Regulated Output Voltage (2.5V). | --- ### Applications * **Battery-Powered Instrumentation:** Due to low current draw. * **Data Acquisition Systems:** Provides a stable reference for ADCs and DACs. * **Portable Medical Devices:** High precision in a small footprint. * **Precision Process Control:** Stable performance across wide temperature ranges.