The **AD8476ARMZ-R7** is a high-precision, low-power, fully differential amplifier (FDA) and ADC driver manufactured by Analog Devices. It is specifically designed to simplify the conversion of single-ended signals to differential signals. ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Function** | Differential Amplifier / ADC Driver | | **Gain** | Fixed G = 1 (Unity Gain) | | **Input Type** | Single-Ended or Differential | | **Output Type** | Differential | | **Supply Voltage (Single)** | 3.0 V to 18 V | | **Supply Voltage (Dual)** | ±1.5 V to ±9 V | | **Supply Current** | ~330 μA (Low Power) | | **Bandwidth (-3dB)** | 5 MHz | | **Package** | 8-Lead MSOP (ARMZ) | | **Tape & Reel** | R7 (7-inch reel, 1000 units) | --- ### 2. Core Functional Blocks #### A. Internal Resistor Network The device features laser-trimmed internal resistors. Because these resistors are integrated on the same die, they have excellent matching characteristics, leading to: * High **CMRR** (Common-Mode Rejection Ratio). * Minimal gain drift over temperature. * Reduced PCB footprint (no external resistors needed for unity gain). #### B. VOCM Pin (Output Common-Mode Control) This pin allows the user to set the output common-mode voltage independently of the input signal. This is critical when interfacing with modern ADCs that require a specific bias voltage (often $V_{REF}/2$) at their inputs. #### C. Differential Output Stage The amplifier converts a standard ground-referenced signal into two balanced outputs ($V_{OUT+}$ and $V_{OUT-}$). This helps in: * Rejecting ground noise. * Doubling the dynamic range for the ADC. * Reducing even-order harmonics. --- ### 3. Application Use-Cases * **ADC Driving:** Specifically tailored for 16-bit and 18-bit SAR (Successive Approximation Register) ADCs. * **Level Shifting:** Shifting high-voltage industrial signals down to low-voltage CMOS ADC levels. * **Single-Ended to Differential Conversion:** Converting sensor signals (like those from a bridge or thermocouple) for differential processing. * **Battery Powered Instrumentation:** Due to its low 330 μA current consumption, it is ideal for portable devices. --- ### 4. Part Number Breakdown (AD8476ARMZ-R7) * **AD8476:** The base model number. * **A:** Performance grade (Standard). * **RM:** Package code for **MSOP** (Mini Small Outline Package). * **Z:** RoHS compliant (Lead-free). * **R7:** Packaging format (7-inch Tape and Reel).