LM311M General Purpose Comparator IC – Equivalent & Substitute Parts

Part Overview

The LM311M is a general purpose comparator IC manufactured by Texas Instruments in 8-SOIC surface mount packaging. This device operates across a wide supply voltage range (5V ~ 36V single supply, ±2.5V ~ 18V dual supply) and features multiple output types including DTL, MOS, Open-Collector, Open-Emitter, RTL, and TTL configurations. The LM311M is currently in Last Time Buy status with 16,903 units in stock. Due to its discontinuation trajectory, identifying functionally equivalent alternatives is essential for long-term design reliability and supply chain continuity.

Substiute Parts

LM311M

Texas InstrumentsIn Stock: 16979LM311M Datasheet

Current PartRFQ

LM311M/NOPB

Texas InstrumentsIn Stock: 2836LM311M/NOPB Datasheet

DirectRFQ

LM211DR2G

onsemiIn Stock: 16142LM211DR2G Datasheet

MFR RecommendedRFQ

LM211DT

STMicroelectronicsIn Stock: 46505LM211DT Datasheet

MFR RecommendedRFQ

LM311D

National SemiconductorIn Stock: 2157LM311D Datasheet

MFR RecommendedRFQ

LM311DR2G

onsemiIn Stock: 516974LM311DR2G Datasheet

MFR RecommendedRFQ

LM311DT

STMicroelectronicsIn Stock: 59659LM311DT Datasheet

MFR RecommendedRFQ

LT1011CS8#PBF

Analog Devices Inc.In Stock: 1365LT1011CS8#PBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM311M is determined by strict alignment across the following critical parameters:

Primary Substitution Criteria:

• Package / Case: 8-SOIC (0.154", 3.90mm Width) – mandatory for PCB compatibility
• Mounting Type: Surface Mount – required for assembly process compatibility
• Type: General Purpose – functional classification
• Number of Elements: 1 – single comparator configuration
• Output Type: Must include Open-Collector capability (core LM311M function)
• Voltage - Supply Range: Minimum 5V ~ 30V single supply or equivalent dual supply
• Voltage - Input Offset (Max): ≤ 7.5mV @ ±15V
• Current - Input Bias (Max): ≤ 0.25µA @ ±15V
• Current - Quiescent (Max): ≤ 7.5mA

Substitute parts are grouped into two categories: Direct Equivalents (identical electrical specifications and packaging) and Functional Equivalents (compatible electrical performance within specified tolerances, same package, different manufacturers or product status).

Parameter Comparison

Engineering Selection Recommendations

Tier 1 – Direct Equivalents (Recommended for Immediate Substitution):

LM311M/NOPB (Texas Instruments) and LM311DR2G (onsemi) are direct functional equivalents with identical electrical specifications to the LM311M. Both maintain the full 5V ~ 36V / ±2.5V ~ 18V supply range, 7.5mV input offset specification, and 0.25µA input bias current. LM311DR2G offers significantly higher inventory (516,900 units) and Active product status, making it the preferred long-term substitute. LM311M/NOPB maintains Texas Instruments sourcing with Active status and 2,775 units available.

Tier 2 – Functional Equivalents with Enhanced Performance:

LM211DR2G (onsemi) and LM211DT (STMicroelectronics) are LM211-series comparators with improved electrical characteristics: 3mV input offset (versus 7.5mV) and 0.1µA input bias current (versus 0.25µA). Both are ROHS3 compliant and Active. Supply voltage range is reduced to 5V ~ 30V / ±2.5V ~ 15V, which remains compatible with standard industrial applications. LM211DT extends operating temperature to -40°C ~ 105°C and provides 50mA output current capability. These parts are suitable for designs where enhanced precision and extended temperature range provide system benefits.

Tier 3 – Alternative Topology:

LT1011CS8#PBF (Analog Devices Inc.) is a precision comparator with superior specifications: 2mV input offset, 0.065µA input bias, 115dB CMRR, and 4mA quiescent current. However, output type is limited to Open-Collector only (versus the multi-output LM311M). This part is suitable for applications requiring only open-collector output and can operate across 3V ~ 36V / ±1.5V ~ 18V supply range. Inventory is limited to 1,278 units.

Not Recommended:

LM311D (National Semiconductor) is Obsolete and RoHS non-compliant. While electrically similar, its discontinued status and regulatory non-compliance make it unsuitable for new designs or long-term supply assurance.

Frequently Asked Questions (FAQ)

Q: Can I use LM211DR2G as a direct replacement for LM311M?

A: LM211DR2G is functionally compatible with LM311M in applications operating within 5V ~ 30V / ±2.5V ~ 15V supply range. Electrical performance is superior (3mV vs. 7.5mV input offset). The primary difference is reduced maximum supply voltage (30V vs. 36V). If your design operates at or below 30V, LM211DR2G is a valid substitute with improved precision.

Q: What is the difference between LM311DR2G and LM311DT?

A: Both are LM311-series comparators with identical electrical specifications and 8-SOIC packaging. LM311DR2G is manufactured by onsemi and supplied in Cut Tape & Digi-Reel packaging. LM311DT is manufactured by STMicroelectronics with identical specifications. Both are Active and ROHS3 compliant. Selection depends on supplier availability and packaging preference (tape & reel vs. cut tape).

Q: Why does LT1011CS8#PBF have different output types?

A: LT1011CS8#PBF is a precision comparator from Analog Devices with Open-Collector output only. The LM311M supports multiple output types (DTL, MOS, Open-Collector, Open-Emitter, RTL, TTL). LT1011CS8#PBF is suitable only for designs requiring open-collector output topology. If your circuit requires DTL, RTL, or TTL outputs, LT1011CS8#PBF is not compatible.

Q: Is the 8-SOIC package identical across all substitute parts?

A: Yes. All listed substitute parts use 8-SOIC (0.154", 3.90mm Width) surface mount packaging. PCB footprints and assembly processes are identical. No layout or manufacturing changes are required when substituting between these parts.

Q: Which substitute part has the best long-term availability?

A: LM311DR2G (onsemi) has the highest inventory at 516,900 units and Active product status, providing the strongest supply assurance. LM311DT (STMicroelectronics) with 59,590 units is the second choice. Both are suitable for designs requiring extended production runs.

Q: Can I use LM211DT in applications requiring -40°C to 105°C operation?

A: Yes. LM211DT is rated for -40°C ~ 105°C operating temperature, compared to LM311M's 0°C ~ 70°C. If your application requires extended temperature range, LM211DT provides this capability while maintaining electrical compatibility within the 5V ~ 30V / ±2.5V ~ 15V supply range.

Q: Are all substitute parts ROHS3 compliant?

A: All substitute parts except LM311D are ROHS3 compliant. LM311D is RoHS non-compliant and Obsolete. For new designs and regulatory compliance, use only ROHS3-compliant alternatives: LM311M/NOPB, LM211DR2G, LM211DT, LM311DR2G, LM311DT, or LT1011CS8#PBF.