Texas Instruments LM339J

Overview

LM339J from Texas Instruments is a quad voltage comparator IC with open-collector outputs, designed for single-supply operation from 2 V to 36 V (or ±1 V to ±18 V). It delivers ±3 mV max input offset voltage, 25 nA input bias current, 0.8 mA supply current per comparator, and 250 mV output saturation voltage at 4 mA-enabling precise threshold detection in industrial control and power monitoring circuits.

For engineers reviewing the LM339J datasheet, LM339J pinout, LM339J application, or LM339J equivalent, key selection considerations include its rail-to-rail input common-mode range including GND, TTL/CMOS-compatible output drive, low-power consumption suitable for battery-backed systems, and robust 36 V absolute maximum supply rating.

Technical Context

The LM339J implements four independent PNP-input comparators on a monolithic silicon die, each featuring uncommitted NPN open-collector outputs capable of sinking up to 16 mA. Its input stage allows common-mode voltages down to ground-even under single-supply operation-eliminating need for level-shifting circuitry in low-side sensing applications.

Each comparator exhibits high DC gain (50–200 V/mV), fast response time (300 ns typical for large overdrive), and differential input voltage tolerance up to 36 V. The device draws supply current independent of V+, enabling stable operation across wide voltage rails without recalibration.

Key Specifications

Pinout & Package

LM339J is supplied in a 14-pin Ceramic Dual In-line Package (CDIP) with nominal body size 19.56 mm × 6.67 mm. This hermetically sealed package provides enhanced reliability for military, aerospace, and high-temperature industrial environments.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad comparator applications.

Compared with LM339N and LM2901N, the LM339J offers superior long-term stability and reliability via ceramic hermetic sealing and military-grade screening-critical for aerospace, defense, and life-critical instrumentation where field failure is unacceptable.

Availability

LM339J is available at Aetrix Electronics and suitable for industrial control systems, power supply supervision, battery management, and high-reliability sensor interface applications requiring stable component supply across extended product lifecycles.

Supply support for LM339J includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of experience delivering high-reliability signal-chain components.

The LM339J belongs to TI's legacy precision comparator family-designed specifically for industrial, military, and aerospace applications demanding wide supply range, ground-sensing capability, and robust open-collector outputs.

FAQ

What is the maximum supply voltage rating for LM339J?

The LM339J has an absolute maximum supply voltage rating of 36 V DC in single-supply mode (or ±18 V in dual-supply mode). Exceeding this limit risks permanent damage. Operation within the recommended 2 V to 36 V range ensures full specification compliance-including input common-mode range, output saturation, and offset voltage performance-across the full −55°C to +125°C temperature range.

Does LM339J support true ground-referenced input operation?

Yes, the LM339J explicitly supports input common-mode voltages down to GND-even when powered from a single positive supply. This is enabled by its PNP input stage architecture, allowing direct connection of sensors or references tied to system ground without level-shifting circuitry. The datasheet confirms "input common-mode voltage range includes GND" as a key feature.

Can LM339J outputs be wired together for OR logic?

Yes, the open-collector outputs of LM339J are expressly designed for wired-OR configurations. Connecting multiple outputs to a shared pull-up resistor creates a logical OR function-commonly used in window comparators, fault-bus aggregation, and priority interrupt generation. No additional components or isolation diodes are required due to the uncommitted collector topology.

What is the typical output sink current capability of LM339J?

The LM339J output transistors can sink up to 16 mA while maintaining specified saturation voltage (≤400 mV at 4 mA, ≤700 mV at full load). This allows direct driving of LEDs, small relays, optocouplers, or TTL/CMOS inputs without external buffers-provided the external pull-up resistor is sized to limit current within this range.

How does LM339J differ from LM339N in terms of reliability and use case?

The LM339J uses a hermetically sealed ceramic DIP package with military-grade screening (MIL-PRF-38535), offering superior moisture resistance, thermal cycling endurance, and long-term parameter stability versus the plastic DIP (PDIP) LM339N. LM339J is selected for aerospace, defense, and critical infrastructure where field failure risk must be minimized-while LM339N targets cost-sensitive commercial applications.