## Overview of LTC2913IDD-2 The **LTC2913IDD-2** is a high-performance, dual input voltage monitor designed for high-reliability systems. It is part of Linear Technology's (now Analog Devices) line of supervisors, optimized for monitoring two independent power supply rails with high precision and low power consumption. --- ### Core Specifications and Features | Feature | Specification / Description | | :--- | :--- | | **Number of Monitors** | 2 Independent Inputs (ADJ1, ADJ2) | | **Threshold Accuracy** | ±1.5% Over Temperature | | **Supply Current** | 40µA (Typical) | | **Input Threshold** | 0.5V (Adjustable via external resistors) | | **Package Type** | DFN-10 (3mm x 3mm) | | **Operating Temp** | -40°C to 85°C (Industrial Grade) | | **Reset Logic** | Active Low Open-Drain outputs | --- ### Functional Pin Breakdown (DFN-10 Package) 1. **VCC**: Power supply input. It can be powered from 2.3V to 6V. 2. **ADJ1 / ADJ2**: High-impedance inputs for the two monitored voltages. Users set the trip points using external resistor dividers. 3. **TMR**: Connection for an external capacitor to adjust the **reset timeout period**. 4. **RST1 / RST2**: Open-drain reset outputs. In the **-2 version**, these outputs are independent (latching/non-latching behavior differs between -1 and -2 variants). 5. **PGI (Power Good Input)**: An additional input used to qualify the reset outputs. 6. **GND**: Ground reference. --- ### Key Technical Advantages * **Adjustable Hysteresis**: The device allows for glitch immunity and stable operation even with noisy power rails. * **Low Power Consumption**: At only 40µA, it is ideal for battery-operated or thermally constrained applications. * **Independent Outputs**: Unlike simple supervisors, the LTC2913-2 allows for independent monitoring of two rails, which is critical for complex FPGA or DSP power-up sequences. * **Polarity Selection**: It can be configured to monitor both positive and negative voltages depending on the wiring of the ADJ pins. --- ### Application Example: Basic Voltage Monitoring To monitor a 3.3V rail, you would use a resistor divider connected to the `ADJ` pin. The trip point is reached when the voltage at the `ADJ` pin falls below **0.5V**. ```python # Example Calculation for Resistor Divider (R1 = Top, R2 = Bottom) # V_threshold = 0.5V * (1 + R1/R2) V_target = 3.0 # Trip at 3.0V for a 3.3V rail R2 = 100000 # 100k Ohm R1 = R2 * ((V_target / 0.5) - 1) # R1 = 500k Ohm ```