LM239J

Overview

The LM239J is a quad differential voltage comparator manufactured by Texas Instruments, designed for operation from a single power supply. It features an open-collector output configuration compatible with TTL, DTL, ECL, MOS, and CMOS logic systems. The device operates within a wide supply voltage range of 2 V to 36 V or dual supplies of ±1 V to ±18 V. Key electrical specifications include a maximum input offset voltage of 5 mV, a typical quiescent current of 2 mA, and a maximum output sink current of 16 mA at 5 V. It supports through-hole mounting in a CDIP-14 package and functions reliably across an operating temperature range of -25 °C to 85 °C.

Feature Summary

• Quad differential input architecture providing four independent comparison channels
• Open-collector outputs enabling direct interfacing with various digital logic families
• Wide single-supply voltage capability allowing operation down to ground potential
• Low power consumption suitable for battery-operated applications

Applications

• Battery-powered monitoring systems requiring low quiescent current
• Voltage level detection circuits interfacing with TTL or CMOS logic
• Window comparator configurations for over-voltage and under-voltage protection
• Analog-to-digital conversion interfaces

Procurement Notes

Verify the specific suffix 'J' indicates the ceramic DIP package variant when sourcing. Confirm RoHS compliance status as older manufacturing runs may contain lead. Ensure the supplier provides official datasheets matching the LM239J designation to distinguish it from plastic package equivalents like the LM239N. Check for active lifecycle status to guarantee long-term availability.

Selection Notes

Select the LM239J when a ruggedized ceramic package is required for high-reliability environments. Consider this part if the design demands open-collector outputs for wired-OR logic connections. Evaluate the 5 mV maximum input offset voltage against system accuracy requirements. Compare the 16 mA output drive capability with load requirements before finalizing the component choice.

Part Context

The LM239J belongs to the LMx39 series of quad comparators from Texas Instruments. This family is characterized by its ability to operate from single supplies while maintaining input common-mode voltage ranges that include ground. The J suffix specifically denotes the ceramic dual in-line package, distinguishing it from plastic variants such as the N suffix. These devices are widely used in industrial control and measurement applications.

Replacement Considerations

The LM239N serves as a pin-compatible alternative offering identical electrical performance in a plastic DIP-14 package. For surface-mount requirements, the LM239DR provides equivalent functionality in an SOIC-14 package. Verify package dimensions and thermal characteristics when substituting between ceramic and plastic variants.