## Overview of ADM1817-R22ART-RL7 The **ADM1817-R22ART-RL7** is a precision microprocessor supervisory circuit (reset IC) manufactured by Analog Devices. It is specifically designed to monitor power supply voltages in microprocessor systems and provide a reset signal during power-up, power-down, and brownout conditions. --- ### Key Technical Specifications | Parameter | Specification | |:---|:---| | **Threshold Voltage ($V_{TH}$)** | 2.18V (Standard for 2.5V nominal supplies) | | **Output Type** | Push-Pull, Active Low | | **Reset Timeout Period** | 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) | | **Temperature Range** | -40°C to +105°C | --- ### Internal Functional Blocks The device consists of several critical electronic components integrated into a single silicon die: 1. **Precision Voltage Reference:** A stable bandgap reference used to compare against the $V_{CC}$ input. 2. **Comparator:** High-speed circuit that triggers when the input voltage drops below the 2.18V threshold. 3. **Delay Generator:** A built-in timer that ensures the reset signal remains active for at least 150ms after $V_{CC}$ rises above the threshold, ensuring the system clock stabilizes. 4. **Push-Pull Output Stage:** Unlike "open-drain" versions, this part has a complementary MOSFET pair. It can source and sink current, meaning it **does not require an external pull-up resistor**. --- ### Part Number Breakdown The suffixing indicates specific configurations: * **ADM1817:** Model series (Push-Pull Output). * **R22:** 2.18V Reset Threshold. * **ART:** SOT-23 Package. * **RL7:** Tape and Reel packaging (7-inch reel). --- ### Application Circuit Example The ADM1817 is extremely simple to integrate because it requires no external components for basic operation. ```markdown VCC (2.5V) | +----|----+ | [VCC] | | ADM1817 |----[RESET OUT]----> To Microcontroller Reset Pin | [GND] | +----|----+ | GND ``` ---