The **ADM1817-R22ARTZ-RL2** is a microprocessor supervisory circuit designed to monitor power supply voltages in computer systems and digital devices. It belongs to the ADM181x family manufactured by Analog Devices. --- ### 1. Key Technical Specifications Below is a breakdown of the primary electrical characteristics for this specific part number: | Feature | Specification | | :--- | :--- | | **Threshold Voltage ($V_{TH}$)** | 2.18V (Nominal) | | **Reset Type** | Active-Low ($RESET$) | | **Output Stage** | Push-Pull | | **Reset Timeout Period** | 100 ms to 600 ms (150 ms typical) | | **Operating Voltage ($V_{CC}$)** | 1.0V to 5.5V | | **Supply Current ($I_{CC}$)** | 20 $\mu$A (Typical) | | **Package Type** | SOT-23 (3-Lead) | | **Operating Temperature** | -40°C to +105°C | --- ### 2. Part Number Breakdown The suffixing in the part number provides specific details about its configuration: * **ADM1817**: The series identifier. * **R22**: Indicates the reset threshold voltage. In this case, it is calibrated for **2.18V**, typically used for monitoring 2.5V power rails. * **ARTZ**: Refers to the package type (SOT-23) and the RoHS compliance (Lead-free). * **RL2**: Refers to the packaging format (Tape and Reel, 2,500 units per reel). --- ### 3. Functional Description The primary role of the ADM1817 is to prevent code execution errors during power-up, power-down, or brownout conditions. #### Reset Logic The device monitors the $V_{CC}$ pin. If the voltage drops below the set threshold (2.18V), the $RESET$ pin is asserted (driven low). Once $V_{CC}$ rises above the threshold again, the reset signal remains active for a "timeout period" (approx. 150ms) to allow the system power to stabilize before the microprocessor starts. #### Push-Pull Output Unlike "Open-Drain" supervisors (like the ADM1815), the ADM1817 uses a **Push-Pull** output stage. - **Advantage**: It does not require an external pull-up resistor. - **Note**: It cannot be wire-OR'ed with other reset sources easily without blocking diodes. --- ### 4. Application Example ```c // Conceptual Logic for a Microcontroller (MCU) connected to ADM1817 if (ADM1817_RESET_PIN == LOW) { // System is in Reset state // MCU remains halted, prevents data corruption } else { // Power is stable (Vcc > 2.18V) // MCU begins initialization sequence } ``` ---