The **ADM824MYRT-R7** is a high-performance supervisory circuit manufactured by Analog Devices. It is designed to monitor power supply voltages in microprocessor systems and provide a reset signal during power-up, power-down, and brownout conditions. --- ### 1. Key Technical Specifications The "MYRT" suffix in the part number defines specific parameters like threshold voltage and packaging. | Parameter | Specification | | :--- | :--- | | **Reset Threshold** | 4.38V (Typical) | | **Output Type** | Push-Pull (Active-High and Active-Low) | | **Supply Voltage (Vcc)** | 1.0V to 5.5V | | **Reset Timeout Period** | 140 ms (Minimum) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | SOT-23-5 | --- ### 2. Core Functional Components The device integrates several critical functions into a single small-outline package: * **Precision Voltage Detector:** Continuously monitors the $V_{CC}$ pin. It triggers a reset if the voltage drops below 4.38V. * **Watchdog Timer:** Monitors software execution. If the microprocessor fails to toggle the Watchdog Input (WDI) within 1.6 seconds, the device asserts a reset. * **Manual Reset (MR) Input:** Allows a user or external logic to trigger a reset pulse regardless of the voltage levels. * **Complementary Reset Outputs:** * **RESET (Pin 1):** Active-low output. * **RESET (Pin 3):** Active-high output. --- ### 3. Pin Configuration The ADM824 uses a standard 5-lead SOT-23 pinout: | Pin No. | Name | Function | | :--- | :--- | :--- | | 1 | $\overline{RESET}$ | Active-Low Output; stays low for 200ms after Vcc rises above threshold. | | 2 | GND | Ground reference. | | 3 | RESET | Active-High Output; inverse of Pin 1. | | 4 | $\overline{MR}$ | Manual Reset Input; active-low. | | 5 | $V_{CC}$ | Supply voltage and monitored input. | --- ### 4. Application Circuit Example In a typical application, the ADM824 ensures the Microcontroller (MCU) does not start executing code until the power supply is stable. ```cpp // Logic Representation of the Watchdog functionality if (system_healthy) { toggle_wdi_pin(); // Prevent ADM824 from resetting the CPU } else { // If this block isn't reached, ADM824 pulls RESET pin after 1.6s } ``` --- ### 5. Part Number Breakdown * **ADM824**: Model series (Supervisory circuit with Watchdog and Manual Reset). * **M**: Threshold voltage code (4.38V). * **YRT**: Package code (SOT-23) and temperature range. * **R7**: Reel size (7-inch reel, typically 3,000 units).