The **ADM824SYKS-R7** is a precision supervisory circuit manufactured by Analog Devices. It is designed to monitor power supply voltages in microprocessor-based systems, providing a reset signal during power-up, power-down, and brownout conditions. --- ### 1. Key Technical Specifications The "S" in the part number indicates a specific threshold voltage, and the "YKS" refers to the package type. | Feature | Specification | | :--- | :--- | | **Reset Threshold** | 2.93V (Standard for 3.3V systems) | | **Output Type** | Push-Pull (Reset) & Open-Drain (Reset Bar) | | **Supply Current** | 5 µA (Typical) | | **Reset Timeout** | 140 ms (Minimum) | | **Operating Temp** | -40°C to +125°C | | **Package** | SC70-5 (5-lead Surface Mount) | --- ### 2. Functional Description The ADM824 combines multiple functions into a tiny footprint to ensure system reliability: * **Power-On Reset (POR):** It keeps the microprocessor in a reset state until the supply voltage reaches a stable level, preventing erratic behavior during startup. * **Watchdog Timer:** It includes an independent watchdog input (WDI). If the microprocessor fails to "kick" or toggle this pin within a specific window (approx. 1.6 seconds), the ADM824 triggers a reset. * **Manual Reset (MR):** Allows for a physical push-button or external logic signal to force a system reset. --- ### 3. Pin Configuration The SC70-5 package utilizes five pins to handle its supervisory tasks: | Pin Number | Name | Description | | :--- | :--- | :--- | | 1 | **RESET** | Active-low logic output. | | 2 | **GND** | Ground reference (0V). | | 3 | **MR** | Manual Reset Input (Active-low). | | 4 | **WDI** | Watchdog Input; triggers reset if left floating or unchanged. | | 5 | **Vcc** | Supply voltage being monitored. | --- ### 4. Typical Application Circuit ```c // Example Logical Connection Flow [Power Source 3.3V] ---> [Vcc Pin 5] [Microcontroller GPIO] ---> [WDI Pin 4] (Heartbeat signal) [Push Button] ---> [MR Pin 3] (Manual override) [Reset Pin 1] ---> [MCU Reset Pin] (Restarts MCU on fault) ``` --- ### 5. Ordering Information Decoded * **ADM824**: Model Series (Supervisory Circuit with Watchdog). * **S**: 2.93V Threshold. * **YKS**: SC70 package designation. * **R7**: 7-inch reel (3,000 pieces) packaging format.