## AD8223BRM-R7: Technical Overview The **AD8223BRM-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, even when operating on a single power supply. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Type** | Instrumentation Amplifier (In-Amp) | | **Gain Range** | 5 to 1,000 (Set by a single external resistor) | | **Supply Voltage** | 3.0 V to 12 V (Single) / ±1.5 V to ±6 V (Dual) | | **Input Type** | Rail-to-Rail Input | | **Output Type** | Rail-to-Rail Output | | **Bandwidth** | 200 kHz (at G=5) | | **Package** | 8-Lead MSOP | | **Packing** | Tape & Reel (indicated by the -R7 suffix) | --- ### 2. Functional Description The AD8223 is a "three-op-amp" instrumentation amplifier architecture. Here are the core electronic characteristics: * **Gain Programming:** The gain ($G$) is calculated using the formula: $G = 5 + \frac{100k\Omega}{R_G}$ Where $R_G$ is the external resistor connected between pins 1 and 8. * **Low Power Consumption:** It draws a maximum quiescent current of only 800 $\mu$A, making it ideal for battery-powered applications. * **Common-Mode Rejection (CMRR):** It features high CMRR (up to 80 dB at G=5), which allows it to filter out noise that is common to both input terminals. * **Wide Input Range:** The input voltage can go slightly below the negative rail (ground in single-supply mode), allowing for ground-sensing applications. --- ### 3. Pin Configuration (8-Lead MSOP) | Pin No. | Mnemonic | Description | | :--- | :--- | :--- | | 1, 8 | $R_G$ | Gain setting terminals (attach resistor here) | | 2 | -IN | Inverting Input | | 3 | +IN | Non-inverting Input | | 4 | -V | Negative Supply (or Ground) | | 5 | REF | Reference terminal (offsets output voltage) | | 6 | OUT | Output terminal | | 7 | +V | Positive Supply voltage | --- ### 4. Typical Applications * **Medical Instrumentation:** ECG and non-invasive blood pressure monitors. * **Industrial Process Control:** Bridge amplifiers for pressure or temperature sensors. * **Precision Data Acquisition:** Interfacing low-level sensors with ADCs. * **Battery Powered Systems:** Portable weigh scales and handheld meters. ---