STMicroelectronics

LM339N

LM339N Description

The LM339N from STMicroelectronics is a general-purpose quad voltage comparator housed in a 14-pin DIP package. Designed for precision analog signal comparison, it operates over a wide supply voltage range (2V to 32V single supply, ±1V to 16V dual supply), making it versatile for various industrial and consumer applications. With a low input bias current (0.25µA @ 5V) and minimal input offset voltage (5mV @ 30V), the LM339N ensures accurate signal detection even in noisy environments. Although marked as obsolete, it remains widely used due to its robust performance and ROHS3 compliance, meeting modern environmental standards.

LM339N Features

• Quad Comparator Design: Four independent comparators in a single package, reducing board space and cost.
• Wide Voltage Range: Supports 2V–32V single supply or ±1V–16V dual supply, ideal for mixed-voltage systems.
• Low Power Consumption: Quiescent current ≤2.5mA, suitable for battery-operated devices.
• High Output Drive: 16mA sink/source capability at 5V, enabling direct interfacing with logic circuits or small relays.
• Stable Performance: MSL 1 (Unlimited) moisture sensitivity ensures reliability in humid conditions.
• Low Input Bias: 0.25µA max minimizes loading effects on high-impedance sources.

LM339N Applications

The LM339N excels in precision threshold detection, oscillators, and voltage monitoring systems. Key use cases include:

• Power Management: Overvoltage/undervoltage protection circuits in PSUs and battery chargers.
• Industrial Control: Window comparators for sensor signal conditioning (e.g., temperature, pressure).
• Consumer Electronics: Zero-crossing detectors in dimmers or motor control circuits.
• Automotive Systems: Fault detection in 12V/24V vehicle networks due to its wide voltage tolerance.

Conclusion of LM339N

Despite its obsolete status, the LM339N remains a cost-effective, reliable choice for analog comparison tasks. Its low power consumption, high noise immunity, and flexible supply range make it a legacy workhorse in industrial, automotive, and consumer designs. Engineers continue to leverage its simplicity and proven performance where modern alternatives may introduce unnecessary complexity.