The **ADM1815-R22ARTZ-R7** is a high-precision voltage monitoring device designed by Analog Devices. It is specifically a **Microprocessor Supervisory Circuit** used to monitor power supplies and provide a reliable reset signal to processors when voltage levels drop below a safe threshold. --- ### 1. Key Technical Specifications Below are the primary electrical and physical characteristics of this specific component: | Feature | Specification | | :--- | :--- | | **Threshold Voltage** | 2.18V (Fixed) | | **Reset Type** | Active-Low | | **Output Stage** | Push-Pull | | **Operating Voltage** | 1.0V to 5.5V | | **Quiescent Current** | 12 µA (Typical) | | **Reset Timeout Delay** | 150 ms (Minimum) | | **Package Type** | SOT-23 (3-Lead) | | **Operating Temp Range** | -40°C to +105°C | --- ### 2. Functional Description The ADM1815 serves as a "watchdog" for system power. Its operation can be broken down into three main stages: 1. **Monitoring:** The chip continuously monitors the $V_{CC}$ pin. 2. **Triggering:** If the supply voltage falls below the **2.18V threshold** (indicated by the "R22" in the part number), the device immediately pulls the $\overline{RESET}$ pin LOW. 3. **Reset Recovery:** Once $V_{CC}$ rises back above the threshold, the device keeps the reset signal active for approximately **150ms** (Reset Timeout). This ensures the power supply has stabilized before the microprocessor begins execution. --- ### 3. Decoding the Part Number The suffix codes provide specific information about the configuration: * **ADM1815:** Base model (Microprocessor Reset Circuit). * **R22:** Indicates a **2.18V** threshold voltage. * **ARTZ:** Refers to the **SOT-23** package and Lead-Free (RoHS) status. * **R7:** Indicates the packaging format, specifically **7-inch Tape and Reel** (typically 3,000 pieces). --- ### 4. Application Circuit (Example) Since this device has a **Push-Pull** output, it does not require an external pull-up resistor to interface with most CMOS/TTL logic inputs. ```text VCC (2.18V - 5V) | +----|----+ | 1 (VCC) | | | | ADM1815 |---- 2 (RESET) ---> To MCU Reset Pin | | | 3 (GND) | +----|----+ | GND ``` ---