LM139DG4

Overview

The LM139DG4 is a quad general-purpose differential voltage comparator manufactured by Texas Instruments. It operates from a single power supply ranging from 2 V to 36 V or dual supplies of ±1 V to ±18 V. The device features four independent channels in a 14-pin SOIC package with an industrial temperature range of -55°C to +125°C. Key electrical specifications include a maximum input offset voltage of 5 mV, a typical response time of 300 ns, and a quiescent current of 500 µA. Each channel provides an open-collector output capable of sinking up to 6 mA.

Feature Summary

• Quad differential input architecture for multi-channel signal comparison
• Open-collector outputs compatible with various logic families including TTL and CMOS
• Wide single-supply operating range extending down to 2 V
• Industrial-grade thermal stability across extended temperature limits

Applications

• Overvoltage and undervoltage detection circuits
• Window comparator configurations
• Logic level shifting between different voltage domains
• Pulse width modulation generation

Procurement Notes

Verify the specific suffix 'G4' indicates lead-free compliance and RoHS status as per manufacturer documentation. Confirm the SOIC-14 package dimensions match PCB footprint requirements. Ensure the industrial temperature rating aligns with environmental constraints. Cross-reference ordering part numbers with official distributor catalogs to avoid obsolete variants.

Selection Notes

Select this component when multiple independent comparisons are required within a single integrated circuit. The open-collector output allows flexible pull-up resistor selection for interfacing with diverse logic levels. Consider the 300 ns propagation delay for timing-sensitive applications. Evaluate the low supply current for battery-operated systems requiring minimal quiescent drain.

Part Context

The LM139DG4 belongs to the LM139 family of analog comparators, which are designed for high-gain differential amplification without feedback. This series is distinct from operational amplifiers, offering faster switching speeds and saturation tolerance. The device serves as a foundational building block for threshold detection and waveform shaping in mixed-signal designs.

Replacement Considerations

LM139DR: Pin-compatible tape-and-reel variant of the same comparator core.