The **LM293DR** is a dual independent precision voltage comparator. It is designed to operate from a single power supply over a wide range of voltages, though it can also operate from split power supplies. --- ### ## Technical Specifications Below is a summary of the core electrical characteristics for the LM293DR: | Parameter | Specification | | :--- | :--- | | **Number of Channels** | 2 (Dual) | | **Supply Voltage (Single)** | 2V to 36V | | **Supply Voltage (Dual)** | ±1V to ±18V | | **Response Time** | 1.3 μs | | **Output Type** | Open Collector | | **Operating Temperature** | -25°C to 85°C | | **Package / Case** | SOIC-8 (R suffix indicates Reel) | --- ### ### Key Features and Internal Parts 1. **Open Collector Output**: The output stage consists of an NPN transistor with an open collector. This means the device can be used in "wired-OR" configurations and allows the output to be pulled up to a different voltage level than the $V_{CC}$ pin, making it ideal for level shifting. 2. **Wide Common-Mode Input Range**: The input common-mode voltage range includes ground ($V_{EE}$), even when operated from a single supply. This allows for sensing signals very close to 0V. 3. **Low Current Drain**: The device is characterized by a very low supply current (typically 0.4 mA), which is independent of the supply voltage. --- ### ### Pinout Configuration (SOIC-8) | Pin Number | Function | Description | | :--- | :--- | :--- | | 1 | **1OUT** | Output of Comparator 1 | | 2 | **1IN-** | Inverting Input of Comparator 1 | | 3 | **1IN+** | Non-inverting Input of Comparator 1 | | 4 | **GND** | Ground (or Negative Supply) | | 5 | **2IN+** | Non-inverting Input of Comparator 2 | | 6 | **2IN-** | Inverting Input of Comparator 2 | | 7 | **2OUT** | Output of Comparator 2 | | 8 | **Vcc** | Positive Supply Voltage | --- ### ### Common Applications * **Limit Comparators**: Monitoring if a voltage goes above or below a threshold. * **Oscillators**: Used in square wave generation circuits. * **Logic Voltage Level Shifting**: Translating 3.3V logic to 5V (or vice versa) using the open-collector output. * **Zero-Crossing Detectors**: Detecting when an AC signal crosses the 0V reference. --- ### ### Comparison Circuit Example ```c // Simplified Logic Diagram // If IN+ > IN- => Output is High Impedance (Pull-up resistor makes it HIGH) // If IN+ < IN- => Output is LOW (Connected to GND) ```