The **MN13811-R** is a CMOS-based voltage detection IC (often called a reset IC) manufactured by Panasonic. It is primarily used to monitor power supply voltage and provide a reset signal to microprocessors or other logic circuits when the voltage drops below a specific threshold. --- ### 1. Key Technical Specifications The "R" suffix in the part number specifically denotes the detection voltage level and output configuration. | Feature | Specification | | :--- | :--- | | **Detection Voltage ($V_{DET}$)** | 4.0V to 4.3V (approx. 4.0V) | | **Hysteresis Width ($\Delta V_{DET}$)** | 200mV (typical) | | **Operating Voltage ($V_{DD}$)** | 1.5V to 6.0V | | **Current Consumption ($I_{DD}$)** | 1.0 $\mu$A (low power consumption) | | **Output Type** | N-channel open drain | | **Package Type** | TO-92 (Standard 3-pin) or Mini-3P | --- ### 2. Pin Configuration The MN13811-R typically follows a standard 3-pin layout: 1. **OUT**: The output pin that sends the reset signal. 2. **VDD**: The power supply input (also the voltage being monitored). 3. **VSS**: Ground. --- ### 3. Functional Principle The device operates based on a precise internal reference voltage and a comparator: * **Normal State:** When the supply voltage ($V_{DD}$) is above the threshold plus hysteresis, the output remains high (or high-impedance in open-drain models). * **Detection State:** When $V_{DD}$ falls below the detection voltage ($V_{DET}$), the output switches to **Low**. * **Recovery:** The output remains Low until $V_{DD}$ rises above $V_{DET} + \Delta V_{DET}$ (the hysteresis voltage), ensuring the system does not "flicker" near the threshold. --- ### 4. Typical Applications * **Microcomputer Reset:** Prevents data corruption by holding the CPU in reset during power-up or "brown-out" (voltage sag) conditions. * **Battery Checkers:** Used to trigger a low-battery indicator. * **Level Discriminators:** Simple circuits that need to toggle logic based on a specific voltage level. --- ### 5. Circuit Example (Open Drain) Because the MN13811-R is an **N-channel open drain** output, it requires a pull-up resistor to function correctly with logic high levels. ```cpp // Basic Wiring Diagram [VDD (Power Source)] ----+---- [Pull-up Resistor] ----+---- [MCU Reset Pin] | | [VDD Pin] [OUT Pin] | | [MN13811-R IC] | | | [VSS Pin] -----------------------+---- [Ground] ```