The **AD8475ARMZ-R7** is a precision, fully differential funnel amplifier (attenuating amplifier) manufactured by Analog Devices. It is designed to drive high-performance precision Analog-to-Digital Converters (ADCs). --- ### ## 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Function** | Precision Differential ADC Driver (Funnel Amp) | | **Gain Settings** | 0.4x and 0.8x (User selectable) | | **Input Type** | Single-ended or Differential | | **Output Type** | Fully Differential | | **Supply Voltage Range** | 3V to 10V (Single) or ±1.5V to ±5V (Dual) | | **Bandwidth (-3dB)** | 85 MHz | | **Slew Rate** | 50 V/µs | | **Package Type** | 8-Lead MSOP (ARMZ) | | **Packaging Format** | Tape & Reel (R7) | --- ### ## 2. Core Features and Functionality #### ### Attenuation (The "Funnel" Action) Unlike standard amplifiers that increase signal strength, the AD8475 is designed to **attenuate** signals. This is critical when you have industrial-level signals (like ±10V) that need to be fed into a low-voltage ADC (typically 0V to 5V). * **G=0.4:** Converts a 10V signal to 4V. * **G=0.8:** Converts a 5V signal to 4V. #### ### Level Shifting The device includes a `VOCM` pin (Voltage Output Common Mode). This allows the user to set the output common-mode voltage independently of the input, making it easy to match the input range requirements of a specific ADC. #### ### Integrated Resistors The gain-setting resistors are integrated on-chip and laser-trimmed. This provides: * Excellent gain accuracy. * Very low drift over temperature. * High Common-Mode Rejection Ratio (CMRR). --- ### ## 3. Pinout Configuration (8-MSOP) | Pin | Name | Description | | :--- | :--- | :--- | | 1 | **VOCM** | Output Common-Mode Voltage input. | | 2 | **VIP** | Positive Input. | | 3 | **VIN** | Negative Input. | | 4 | **-Vs** | Negative Supply (or Ground). | | 5 | **+Vs** | Positive Supply. | | 6 | **VON** | Negative Differential Output. | | 7 | **VOP** | Positive Differential Output. | | 8 | **GAIN** | Gain Select (Connect to GND or leave open). | --- ### ## 4. Typical Application Circuit The AD8475 acts as the interface between a high-voltage sensor and a low-voltage microcontroller system. ```markdown [Sensor ±10V] ---> [AD8475 (G=0.4)] ---> [Differential ADC (0-4V)] ^ | [Vref/2 Logic] ``` --- ### ## 5. Part Number Decoding (AD8475ARMZ-R7) * **AD8475:** Base model number. * **A:** Performance grade. * **RM:** Package code for MSOP (Mini Small Outline Package). * **Z:** RoHS compliant / Lead-free. * **R7:** 7-inch reel packaging (standard for automated SMT assembly).