LM139J/PB

Overview

The LM139J/PB is a low-power, low-offset voltage quad comparator manufactured by Texas Instruments. It features four independent precision voltage comparators in a single package. The device operates within a supply voltage range of 2V to 36V or ±1V to ±18V. It offers a typical propagation delay of 1.3 µs and a maximum input offset voltage of 2 mV. The component is housed in a 14-pin Ceramic Dual In-Line Package (CDIP-J) and supports an operating temperature range from -55°C to 125°C.

Feature Summary

• Quad configuration providing four independent differential comparators for multi-channel signal processing
• Low offset voltage specification ensuring high precision in voltage comparison applications
• Wide single or dual power supply operation capability for flexible system integration
• Open-collector outputs allowing easy interfacing with various logic families and pull-up configurations

Applications

• Precision voltage monitoring circuits
• Level detection systems
• Analog-to-digital converter front-ends
• Over-voltage protection circuits

Procurement Notes

Verify the package type CDIP-J matches your PCB footprint requirements. Confirm the suffix /PB indicates lead-free compliance if required by your manufacturing process. Check the specific revision of the datasheet for any updates on electrical characteristics or mechanical dimensions before finalizing the design.

Selection Notes

Select this component when multiple independent comparators are needed in a space-constrained environment. Consider the open-collector output structure for compatibility with different voltage levels. Evaluate the 1.3 µs propagation delay against your signal speed requirements to ensure adequate response time for the intended application.

Part Context

The LM139 series is a widely used family of quad comparators known for stability and low power consumption. The J variant specifically denotes the military-grade or high-reliability ceramic package version, offering enhanced durability compared to plastic packages. This part serves as a direct replacement for older LM139 designs requiring higher reliability.

Replacement Considerations

Direct pin-compatible substitutes include other LM139 variants such as LM139N or LM139Q, depending on package and grade requirements. Verify that alternative parts maintain the same quad comparator architecture and open-collector output specifications to ensure circuit compatibility without redesign.