## Overview of AD8223BRMZ-R7 The **AD8223BRMZ-R7** is an integrated, single-supply, rail-to-rail instrumentation amplifier manufactured by **Analog Devices**. It is designed to amplify small differential signals in the presence of large common-mode voltages, making it ideal for precision sensor interface applications. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Architecture** | 3-Op Amp Instrumentation Amplifier | | **Supply Voltage** | 3V to 12V (Single) / ±1.5V to ±6V (Dual) | | **Gain Range** | 5 to 1000 (Set by a single external resistor) | | **Common-Mode Rejection Ratio (CMRR)** | 80 dB (G=5) to 110 dB (G=1000) | | **Input Bias Current** | 20 nA (Max) | | **Quiescent Current** | 600 µA (Max) | | **Package Type** | 8-Lead MSOP (Micro Small Outline Package) | | **Output Type** | Rail-to-Rail | --- ### 2. Core Features * **Single Resistor Gain Set:** The gain is programmed using one external resistor ($R_G$). If no resistor is used, the default gain is 5. * **Rail-to-Rail Output:** The output swing can reach within millivolts of the supply rails, maximizing the dynamic range for low-voltage ADCs. * **Micropower Design:** With a maximum current consumption of 600 µA, it is suitable for battery-powered or portable devices. * **Wide Input Range:** The input voltage range extends from the negative rail (ground) up to approximately 1V from the positive rail. --- ### 3. Pin Configuration (8-Lead MSOP) | Pin No. | Mnemonic | Description | | :--- | :--- | :--- | | 1 | **-IN** | Inverting Input | | 2 | **RG** | Gain Setting Terminal | | 3 | **RG** | Gain Setting Terminal | | 4 | **+IN** | Non-inverting Input | | 5 | **-Vs** | Negative Supply (or Ground) | | 6 | **REF** | Reference Terminal (Sets output offset) | | 7 | **Vout** | Output Terminal | | 8 | **+Vs** | Positive Supply Voltage | --- ### 4. Gain Calculation The gain ($G$) of the AD8223 is determined by the value of the resistor $R_G$ connected between Pin 2 and Pin 3. The formula is: ```math G = 5 + \frac{100\text{ k}\Omega}{R_G} ``` * **Example:** For a gain of 100, $R_G \approx 1.05\text{ k}\Omega$. --- ### 5. Typical Applications * **Medical Instrumentation:** ECG and EEG monitoring. * **Industrial Sensors:** Pressure transducers and strain gauges (Bridge interfaces). * **Data Acquisition:** Signal conditioning for microcontrollers and ADCs. * **Portable Equipment:** Battery-operated weighing scales. ---