## Overview of TS391A-AF5-R The **TS391A-AF5-R** is a low-power, single voltage comparator integrated circuit (IC) manufactured by UTC (Unisonic Technologies). It is designed to operate over a wide range of supply voltages and is particularly suited for battery-operated systems due to its low current consumption. --- ### Technical Specifications The following table outlines the primary electrical characteristics and physical parameters of the device: | Parameter | Specification | | :--- | :--- | | **Type** | Single Voltage Comparator | | **Supply Voltage Range** | 2V to 36V (or ±1V to ±18V) | | **Current Consumption** | 0.8mA (Typical) | | **Output Type** | Open Collector | | **Package Type** | SOT-25 / SOT-23-5 | | **Response Time** | 1.3μs | | **Input Offset Voltage** | 2mV (Typical) | --- ### Key Electronic Components & Internal Logic The TS391A consists of several critical internal sections that define its behavior: 1. **Differential Input Stage**: This stage compares the voltages at the Inverting (-) and Non-Inverting (+) pins. It is designed to allow common-mode sensing down to the ground level, even when operating from a single power supply. 2. **Open-Collector Output**: The output stage uses an NPN transistor with an open collector. This means the device does not "push" voltage out; it only "pulls" it to ground. * *Note:* A pull-up resistor is required to interface with logic levels (e.g., 3.3V, 5V, or 15V). 3. **Frequency Compensation**: While comparators are generally used for switching, the internal design minimizes oscillations during the transition period. --- ### Pin Configuration (SOT-25) | Pin Number | Symbol | Function | | :--- | :--- | :--- | | 1 | OUT | Output (Open Collector) | | 2 | VCC | Positive Supply Voltage | | 3 | GND | Ground / Negative Supply | | 4 | IN+ | Non-Inverting Input | | 5 | IN- | Inverting Input | --- ### Applications * **Limit Comparators**: Detecting when a voltage exceeds a specific threshold. * **Zero-Crossing Detectors**: Identifying when an AC signal crosses 0V. * **A/D Converters**: Used in simple dual-slope or flash converters. * **Logic Level Shifting**: Because of the open-collector output, it can bridge circuits operating at different voltages (e.g., 5V logic to 12V logic).