LM311N Equivalent & Substitute Parts

Part Overview

The LM311N is a general-purpose comparator IC manufactured by Texas Instruments, housed in an 8-DIP package for through-hole mounting. This device is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing design support and procurement. The LM311N provides single-element comparison functionality with multiple output types including DTL, MOS, Open-Collector, Open-Emitter, RTL, and TTL configurations, making it suitable for applications requiring flexible output interfacing across legacy and modern circuit designs.

Substiute Parts

LM311N

Texas InstrumentsIn Stock: 7447LM311N Datasheet

Current PartRFQ

LM311N/NOPB

Texas InstrumentsIn Stock: 5394LM311N/NOPB Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM311N is determined by strict equivalence across the following critical parameters:

• Functional Type: General Purpose Comparator with single element
• Output Configuration: DTL, MOS, Open-Collector, Open-Emitter, RTL, TTL compatibility
• Supply Voltage Range: 5V ~ 36V single supply or ±2.5V ~ 18V dual supply
• Input Offset Voltage: Maximum 7.5mV @ ±15V
• Input Bias Current: Maximum 0.25µA @ ±15V
• Output Current Capability: Typical 50mA
• Quiescent Current: Maximum 7.5mA
• Operating Temperature Range: 0°C ~ 70°C
• Package Format: 8-DIP through-hole mounting

The LM311N/NOPB variant meets all electrical and mechanical parameters of the original LM311N while offering improved product status and compliance characteristics. Both parts share identical base product designation (LM311) and are pin-compatible within the 8-DIP package specification.

Parameter Comparison

Engineering Selection Recommendations

The LM311N/NOPB is the direct functional equivalent of the LM311N, maintaining complete electrical and mechanical compatibility while offering superior product lifecycle status. The LM311N/NOPB is classified as Active, ensuring continued availability and manufacturer support. Additionally, the LM311N/NOPB achieves ROHS3 compliance, addressing regulatory requirements for new designs and procurement in regulated industries, whereas the original LM311N is RoHS non-compliant.

For applications requiring the LM311N, the LM311N/NOPB should be selected as the primary substitute. Both devices are supplied in 8-DIP through-hole packages and require no circuit modifications for direct replacement. The electrical performance characteristics remain identical across all specified parameters, ensuring functional equivalence in existing circuit designs.

Frequently Asked Questions (FAQ)

Q: Can the LM311N/NOPB directly replace the LM311N in existing designs?

A: Yes. The LM311N/NOPB is electrically and mechanically equivalent to the LM311N. Both devices share identical pin configurations, supply voltage ranges, input offset specifications, output current capabilities, and operating temperature ranges. Direct substitution requires no circuit modifications.

Q: What is the significance of the "/NOPB" suffix in the LM311N/NOPB part number?

A: The "/NOPB" designation indicates lead-free (no lead) and RoHS3 compliant packaging. This suffix reflects manufacturing and environmental compliance standards without affecting electrical performance or pin compatibility.

Q: Are there differences in packaging between LM311N and LM311N/NOPB?

A: Both devices use the 8-DIP (0.300", 7.62mm) through-hole package format. The LM311N/NOPB is supplied in Tube packaging, while the original LM311N packaging specification is not detailed. Both are compatible with standard through-hole PCB layouts.

Q: Why is the LM311N classified as obsolete?

A: The LM311N has reached end-of-life status with Texas Instruments. The LM311N/NOPB represents the active continuation of this product line, offering the same functionality with modern compliance certifications.

Q: What are the key electrical parameters that define substitution compatibility?

A: Substitution compatibility is determined by: supply voltage range (5V ~ 36V or ±2.5V ~ 18V), input offset voltage (7.5mV maximum), input bias current (0.25µA maximum), output current capability (50mA typical), quiescent current (7.5mA maximum), and operating temperature range (0°C ~ 70°C). All substitute parts must match these specifications exactly.

Q: Is the LM311N/NOPB suitable for new product designs?

A: Yes. The LM311N/NOPB is classified as Active and meets current RoHS3 compliance requirements, making it appropriate for new designs requiring general-purpose comparator functionality with flexible output configurations.