LM393N - Dual Differential Comparator

Overview

The LM393N is a dual independent precision voltage comparator from the LM193 series, designed for reliable operation across a wide range of supply voltages. This component features exceptionally low offset voltage (2.0 mV max for both comparators) and operates efficiently from single or split power supplies. Its input common-mode voltage range includes ground, making it particularly suitable for single-supply applications. The LM393N is widely used in industrial, automotive, and consumer electronics due to its robust performance and low power consumption.

Key Features

• Wide Supply Voltage Range: Operates from 2.0V to 36V with single supply or ±1.0V to ±18V with dual supplies.
• Low Power Consumption: Very low supply current drain (0.4 mA typical), independent of supply voltage magnitude.
• Ground-Inclusive Input Range: Input common-mode voltage range includes ground, enabling single-supply operation.
• Low Offset Voltage: Maximum offset voltage of 2.0 mV for precise comparison tasks.
• Dual Comparator Design: Two independent comparators in a single package, saving board space.
• High Stability: Designed for reliable operation across temperature variations and noisy environments.

Applications

The LM393N is versatile and finds use in numerous applications, including:

• Voltage Monitoring: Over-voltage and under-voltage detection in power supplies.
• Analog-to-Digital Conversion: Signal conditioning for ADCs in embedded systems.
• Zero-Crossing Detectors: Used in AC phase control and switching circuits.
• Oscillators and Waveform Generators: Timing and pulse generation in signal processing.
• Automotive Systems: Battery monitoring, sensor interfaces, and control modules.
• Consumer Electronics: Level detection in audio equipment, power management circuits.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V_CC): 36V or ±18V
• Input Differential Voltage: ±36V
• Input Common-Mode Voltage: -0.3V to V_CC + 0.3V
• Output Sink Current: 16 mA (per comparator)
• Operating Temperature Range: -25°C to +85°C (industrial grade)

Typical Performance Characteristics

• Input Offset Voltage: 1.0 mV (typ), 2.0 mV (max)
• Input Bias Current: 25 nA (typ)
• Response Time (for 100 mV overdrive): 1.3 μs (typ)
• Supply Current (both comparators): 0.4 mA (typ)
• Output Saturation Voltage: 250 mV (at 4 mA sink current)

Package Information

8-Pin DIP (Dual Inline Package)

• Package Type: PDIP-8
• Dimensions: 9.81 mm x 6.35 mm
• Pin Configuration:
  • Pin 1: Output 1
  • Pin 2: Inverting Input 1
  • Pin 3: Non-Inverting Input 1
  • Pin 4: Ground
  • Pin 5: Non-Inverting Input 2
  • Pin 6: Inverting Input 2
  • Pin 7: Output 2
  • Pin 8: V_CC (Positive Supply)

Surface Mount Option (SOIC-8)

• Package Type: SOIC-8
• Dimensions: 4.90 mm x 3.91 mm
• Thermal Resistance (θ_JA): 160°C/W

Design Considerations

When implementing the LM393N in a circuit, consider the following:

• Power Supply Decoupling: Use a 0.1 μF ceramic capacitor close to the V_CC pin to minimize noise.
• Output Configuration: The open-collector outputs require pull-up resistors (typically 1kΩ to 10kΩ) for proper logic-level output.
• Input Protection: Avoid exceeding the absolute maximum input voltage range to prevent damage.
• Thermal Management: In high-temperature environments, ensure adequate airflow or heat sinking for the SOIC package.

Conclusion

The LM393N dual voltage comparator offers excellent precision and flexibility for a wide range of analog comparison applications. Its ability to operate from single or dual supplies, combined with low power consumption and ground-inclusive input range, makes it a preferred choice for designers working on battery-powered or space-constrained systems. The availability in both through-hole (DIP) and surface-mount (SOIC) packages further enhances its versatility across different manufacturing processes.