## Technical Overview: ADR5040AKSZ-R2 The **ADR5040AKSZ-R2** is a high-precision, shunt-mode voltage reference manufactured by **Analog Devices**. It is designed for space-constrained applications requiring high stability and low power consumption. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Output Voltage ($V_{out}$)** | 2.048 V | | **Initial Accuracy** | ±0.1% (Grade A) | | **Temperature Coefficient** | 100 ppm/°C | | **Operating Current Range** | 50 µA to 15 mA | | **Package Type** | SC70-3 (Small Outline Transistor) | | **Operating Temperature** | -40°C to +125°C | | **Output Noise (0.1Hz to 10Hz)** | 120 µV p-p | --- ### 2. Functional Description The ADR5040 is a **Shunt Voltage Reference**. Unlike a series reference, it operates similarly to a Zener diode, maintaining a constant voltage across its terminals by adjusting the current it draws. #### Internal Block Diagram Components: * **Bandgap Reference Core:** Provides the stable 2.048V output based on the physical properties of silicon. * **Error Amplifier:** Monitors the output and adjusts the internal shunt transistor to maintain regulation. * **Feedback Network:** Precision resistors that define the specific 2.048V output. --- ### 3. Application Circuitry To use the ADR5040, an external current-limiting resistor ($R_{bias}$) is required to ensure the device operates within its 50 µA to 15 mA range. ```c // Calculation for Bias Resistor (R_bias) // R_bias = (V_supply - V_out) / (I_load + I_shunt) // Example: // V_supply = 5V // V_out = 2.048V // Desired I_shunt = 1mA // R_bias = (5 - 2.048) / 0.001 = 2952 Ohms (~3kOhm) ``` --- ### 4. Comparison of Variants (ADR5040 Series) | Part Number | Initial Accuracy | Temp. Coefficient | | :--- | :--- | :--- | | ADR5040**A**KSZ | ±0.1% (2 mV) | 100 ppm/°C | | ADR5040**B**KSZ | ±0.2% (4 mV) | 75 ppm/°C | *Note: The **R2** suffix in the part number indicates the packaging format (7-inch reel with 250 units).* --- ### 5. Common Use Cases * **ADC/DAC Referencing:** The 2.048V output is ideal for 12-bit converters because it equates to exactly 0.5mV per bit. * **Precision Current Sources:** Used as a stable voltage drop across a sense resistor. * **Portable Instrumentation:** Due to the ultra-small SC70 footprint and low minimum operating current (50 µA).