## Technical Overview: ADM6328-25ARTZ-R7 The **ADM6328-25ARTZ-R7** is an ultra-low-power microprocessor supervisory circuit manufactured by **Analog Devices**. It is designed to monitor power supply voltages in microprocessor-based systems and initiate a reset pulse during power-up, power-down, and brownout conditions. --- ### Key Specifications | Feature | Specification | | :--- | :--- | | **Reset Threshold** | 2.5V (Nominal) | | **Output Type** | Open-Drain (Active-Low) | | **Supply Current** | 1 µA (Typical) | | **Reset Timeout** | 100 ms (Minimum) | | **Package / Case** | SOT-23-3 | | **Operating Temp** | -40°C to +85°C | --- ### Core Electronic Components & Architecture The internal circuitry consists of four primary stages that work together to ensure system stability: 1. **Precision Voltage Reference:** An internal bandgap reference provides a stable voltage used as a benchmark to compare against the $V_{CC}$ input. 2. **Comparator:** This component constantly compares the monitored supply voltage to the fixed threshold (2.5V). It includes **hysteresis** to prevent "chattering" (rapid toggling) when the voltage is near the threshold. 3. **Time Delay Circuit:** Once the supply voltage rises above the threshold, a timer prevents the reset from releasing immediately. This ensures the power supply has fully stabilized before the MCU starts. 4. **Open-Drain Output Stage:** The output ($/RESET$) is an N-channel MOSFET. * **Note:** Since it is open-drain, it requires an external **pull-up resistor** connected to a voltage source (usually $V_{CC}$ or the I/O voltage of the processor). --- ### Functional Pinout | Pin Number | Name | Description | | :--- | :--- | :--- | | **1** | $/RESET$ | Active-low output. Asserts when $V_{CC}$ is below the threshold. | | **2** | $V_{CC}$ | Supply voltage input and monitored voltage sense pin. | | **3** | $GND$ | Ground reference. | --- ### Typical Application Circuit ```mermaid graph LR VCC(VCC 2.5V/3.3V) --- R1[Pull-up Resistor] R1 --- RESET_PIN[ADM6328 /RESET Pin] RESET_PIN --- MCU[Microcontroller Reset Pin] VCC --- ADM_VCC[ADM6328 VCC Pin] GND --- ADM_GND[ADM6328 GND Pin] ``` --- ### Why use this part? * **Battery Efficiency:** With a 1 µA current draw, it is ideal for portable electronics where power conservation is critical. * **Reliability:** It eliminates the need for discrete RC reset circuits, which are often unreliable due to slow rise times and sensitivity to temperature. * **Glitches:** The device is designed to ignore very short fast transients on the $V_{CC}$ line, preventing unnecessary system resets.