The **ADR5044WARTZ-R7** is a precision shunt voltage reference manufactured by Analog Devices. It is specifically designed for high-accuracy applications in space-constrained environments, particularly within the automotive sector. ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Output Voltage ($V_{out}$)** | 4.096 V | | **Initial Accuracy** | ±0.1% (Grade B) | | **Temperature Coefficient** | 75 ppm/°C | | **Operating Current Range** | 50 µA to 15 mA | | **Package Type** | SOT-23-3 | | **Operating Temperature** | -40°C to +125°C | | **Automotive Qualified** | Yes (AEC-Q100) | --- ### 2. Functional Description Unlike a series reference, the ADR5044 acts as a **Shunt Reference**. This means it operates similarly to a Zener diode, maintaining a constant voltage by "shunting" excess current to ground. * **Fixed Output:** It provides a stable 4.096V output, which is ideal for 12-bit Analog-to-Digital Converters (ADCs) because it simplifies the LSB (Least Significant Bit) calculation (exactly 1 mV per step). * **No External Capacitor Required:** It is designed to be stable without an output capacitor, though one can be added to reduce noise if necessary. * **AEC-Q100 Rating:** The "W" in the part number indicates automotive qualification, meaning it is tested to withstand harsh vehicle environments. --- ### 3. Application Circuit Example To use this part, you must place a current-limiting resistor ($R_{set}$) between the input voltage and the reference. ```text Vin ----[ R_set ]----+---- Vout (4.096V) | [ADR5044] | GND ``` #### Calculating $R_{set}$: To calculate the resistor value, use the following formula: $$R_{set} = \frac{V_{in(min)} - V_{out}}{I_{load(max)} + I_{q(min)}}$$ *Where $I_q$ is the minimum operating current (50 µA).* --- ### 4. Pin Configuration (SOT-23) | Pin Number | Name | Function | | :--- | :--- | :--- | | 1 | **K** | Cathode (Positive Terminal) | | 2 | **NC** | No Connect (Leave floating) | | 3 | **A** | Anode (Connected to Ground) | --- ### 5. Common Use Cases 1. **Automotive Systems:** Battery monitoring, sensor conditioning, and ECU power rails. 2. **Data Acquisition:** Precise voltage biasing for 12-bit ADCs and DACs. 3. **Portable Instrumentation:** Due to its low minimum operating current (50 µA), it is excellent for battery-powered devices.