LM318MX Equivalent & Substitute Parts

Part Overview

The LM318MX is a general-purpose operational amplifier manufactured by Texas Instruments in an 8-SOIC surface mount package. This device is classified as obsolete, though 3900 units remain in stock. The LM318MX operates across a supply voltage range of 10V to 40V with a slew rate of 70V/µs and gain bandwidth product of 15 MHz, making it suitable for general-purpose amplification applications requiring moderate bandwidth and speed.

Due to its obsolete status, identifying equivalent and substitute parts is necessary for design continuity, long-term availability assurance, and potential performance improvements. Active alternatives are available from both Texas Instruments and other manufacturers that maintain compatible electrical and mechanical specifications.

Substiute Parts

LM318MX

Texas InstrumentsIn Stock: 3942LM318MX Datasheet

Current PartRFQ

LM318MX/NOPB

Texas InstrumentsIn Stock: 12607LM318MX/NOPB Datasheet

DirectRFQ

AD797ARZ

Analog Devices Inc.In Stock: 15615AD797ARZ Datasheet

MFR RecommendedRFQ

AD797ARZ-REEL

Analog Devices Inc.In Stock: 889338AD797ARZ-REEL Datasheet

MFR RecommendedRFQ

AD797ARZ-REEL7

Analog Devices Inc.In Stock: 16660AD797ARZ-REEL7 Datasheet

MFR RecommendedRFQ

AD797BRZ

Analog Devices Inc.In Stock: 3439AD797BRZ Datasheet

MFR RecommendedRFQ

AD797BRZ-REEL

Analog Devices Inc.In Stock: 2027AD797BRZ-REEL Datasheet

MFR RecommendedRFQ

AD797BRZ-REEL7

Analog Devices Inc.In Stock: 5219AD797BRZ-REEL7 Datasheet

MFR RecommendedRFQ

LM201ADR2G

onsemiIn Stock: 25409LM201ADR2G Datasheet

MFR RecommendedRFQ

LM201ADT

STMicroelectronicsIn Stock: 271787LM201ADT Datasheet

MFR RecommendedRFQ

LM201AVDR2G

onsemiIn Stock: 355310LM201AVDR2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM318MX is determined by strict compatibility across electrical and mechanical parameters. The following criteria define valid substitutes:

Primary Compatibility Criteria:

• Package / Case: 8-SOIC (0.154", 3.90mm Width) — mandatory for PCB layout compatibility
• Mounting Type: Surface Mount — required for assembly process compatibility
• Amplifier Type: General Purpose — functional category match
• Number of Circuits: 1 — single amplifier per package

Electrical Parameter Ranges for Substitution:

• Voltage - Supply Span: Minimum ≥ 10V, Maximum ≥ 40V (LM318MX operates 10V–40V)
• Slew Rate: ≥ 70V/µs (LM318MX: 70V/µs)
• Gain Bandwidth Product: ≥ 15 MHz (LM318MX: 15 MHz)
• Current - Input Bias: ≤ 150 nA (LM318MX: 150 nA)
• Voltage - Input Offset: ≤ 4 mV (LM318MX: 4 mV)
• Current - Supply: ≤ 5 mA (LM318MX: 5 mA)

Compliance & Status Considerations:

• Product Status: Active substitutes are preferred over obsolete parts
• RoHS Status: ROHS3 Compliant substitutes are available
• Regulatory: REACH Unaffected and EAR99 classification maintained across all substitutes

Substitutes are grouped into two categories based on electrical performance relative to the LM318MX baseline:

Category A — Direct Electrical Equivalents (Texas Instruments LM318 Series): LM318MX/NOPB meets all electrical parameters identically to LM318MX. This is the primary direct substitute, differing only in product status (Active vs. Obsolete) and RoHS compliance (ROHS3 Compliant vs. non-compliant).

Category B — Enhanced Performance Alternatives (Analog Devices AD797 Series): AD797ARZ, AD797ARZ-REEL, AD797ARZ-REEL7, AD797BRZ, AD797BRZ-REEL, and AD797BRZ-REEL7 exceed LM318MX electrical specifications. These parts operate within the required 10V–30V supply range (subset of LM318MX's 10V–40V), but deliver superior performance: slew rate of 20V/µs (vs. 70V/µs required), gain bandwidth product of 110 MHz (vs. 15 MHz required), and lower input offset voltage (10–25 µV vs. 4 mV). These are suitable for applications where enhanced precision and bandwidth are beneficial.

Category C — Lower Performance Alternatives (onsemi/STMicroelectronics LM201 Series): LM201ADR2G, LM201ADT, and LM201AVDR2G do not meet the electrical parameter requirements for direct substitution. Slew rate is 0.5V/µs (below 70V/µs requirement), gain bandwidth product is 1 MHz (below 15 MHz requirement), and input offset voltage is 700 µV (below 4 mV requirement). These parts are listed for reference only and are not suitable substitutes for LM318MX applications.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: LM318MX/NOPB

The LM318MX/NOPB is the optimal substitute for the obsolete LM318MX. This part is manufactured by Texas Instruments and maintains identical electrical specifications across all critical parameters: 70V/µs slew rate, 15 MHz gain bandwidth product, 150 nA input bias current, 4 mV input offset voltage, and 5 mA supply current. The 8-SOIC package and surface mount configuration are identical, ensuring direct PCB compatibility without layout modifications.

The LM318MX/NOPB differs from the original LM318MX in two aspects: it carries Active product status (vs. Obsolete) and is ROHS3 Compliant (vs. non-compliant). These differences represent improvements for long-term supply chain reliability and regulatory compliance. Inventory availability is significantly higher at 12,568 units compared to 3,900 units of the original part. This part is suitable for all applications currently using LM318MX without circuit redesign.

Secondary Recommendation: AD797ARZ-REEL or AD797ARZ-REEL7

The Analog Devices AD797 series (AD797ARZ, AD797ARZ-REEL, AD797ARZ-REEL7, AD797BRZ, AD797BRZ-REEL, AD797BRZ-REEL7) represents an enhanced performance alternative. These parts maintain the 8-SOIC package and surface mount configuration, ensuring mechanical compatibility. All AD797 variants are Active products with ROHS3 Compliance.

The AD797 series operates within a 10V–30V supply range, which is a subset of the LM318MX's 10V–40V range. Applications operating above 30V supply voltage cannot use AD797 substitutes. For applications within the 10V–30V range, the AD797 series offers superior performance: 110 MHz gain bandwidth product (vs. 15 MHz), 20V/µs slew rate (vs. 70V/µs), and significantly lower input offset voltage (10–25 µV vs. 4 mV). The AD797BRZ and AD797BRZ-REEL7 variants offer the lowest input offset voltage at 10 µV.

AD797ARZ-REEL offers the highest inventory availability at 889,288 units in Tape & Reel packaging, suitable for high-volume production. AD797ARZ-REEL7 provides 16,620 units in Cut Tape & Digi-Reel format for smaller quantity requirements.

Regulatory & Compliance Status:

All recommended substitutes maintain EAR99 export classification and REACH Unaffected status, matching the original LM318MX. All substitutes carry MSL 1 (Unlimited) moisture sensitivity rating. The transition from RoHS non-compliant (LM318MX) to ROHS3 Compliant (LM318MX/NOPB and AD797 series) aligns with current regulatory requirements for electronic components in most markets.

Frequently Asked Questions (FAQ)

Q1: Can LM318MX/NOPB be used as a direct replacement for LM318MX without circuit modifications?

A: Yes. The LM318MX/NOPB is electrically and mechanically identical to LM318MX. All electrical parameters—slew rate, bandwidth, input bias current, input offset voltage, and supply current—are identical. The 8-SOIC package dimensions and surface mount configuration are unchanged. No PCB layout modifications or circuit redesign is required. The only differences are product status (Active vs. Obsolete) and RoHS compliance (ROHS3 vs. non-compliant), both of which are improvements.

Q2: What is the key difference between LM318MX and the AD797 series?

A: The LM318MX and AD797 series differ in performance specifications and supply voltage range. The LM318MX operates at 10V–40V supply with 70V/µs slew rate and 15 MHz bandwidth. The AD797 series operates at 10V–30V supply with 20V/µs slew rate and 110 MHz bandwidth. The AD797 series provides higher bandwidth and lower input offset voltage (10–25 µV vs. 4 mV), making it suitable for precision applications. However, the AD797 cannot be used in circuits requiring supply voltages above 30V.

Q3: Are all AD797 variants (ARZ, ARZ-REEL, ARZ-REEL7, BRZ, BRZ-REEL, BRZ-REEL7) electrically equivalent?

A: The AD797 variants are electrically equivalent within their respective grades. AD797ARZ and AD797ARZ-REEL variants have 25 µV input offset voltage. AD797BRZ and AD797BRZ-REEL variants have 10 µV input offset voltage, offering superior precision. The differences between variants are packaging format (Tube, Tape & Reel, or Cut Tape & Digi-Reel) and inventory availability, not electrical performance. Select the variant based on packaging requirements and quantity needs.

Q4: Can the LM201 series (LM201ADR2G, LM201ADT, LM201AVDR2G) substitute for LM318MX?

A: No. The LM201 series does not meet the electrical requirements for LM318MX substitution. The LM201 series has 0.5V/µs slew rate (vs. 70V/µs required), 1 MHz gain bandwidth product (vs. 15 MHz required), and 700 µV input offset voltage (vs. 4 mV required). These parts are significantly slower and less precise. The LM201 series is suitable only for low-speed, low-precision applications and cannot replace LM318MX in existing designs.

Q5: What packaging options are available for the recommended substitutes?

A: LM318MX/NOPB is available in Cut Tape (CT) & Digi-Reel format. The AD797 series offers multiple packaging options: AD797ARZ (Tube), AD797ARZ-REEL (Tape & Reel), AD797ARZ-REEL7 (Cut Tape & Digi-Reel), AD797BRZ (Tube), AD797BRZ-REEL (unspecified), and AD797BRZ-REEL7 (Cut Tape & Digi-Reel). Select packaging based on assembly process requirements: Tube for manual or small-batch assembly, Tape & Reel for automated high-volume production, and Cut Tape & Digi-Reel for mixed-volume requirements.

Q6: What is the operating temperature range difference between LM318MX and its substitutes?

A: The LM318MX operates from 0°C to 70°C. The LM318MX/NOPB maintains the same 0°C to 70°C range. The AD797 series extends the operating range to -40°C to 85°C, providing wider temperature coverage. For applications requiring operation below 0°C or above 70°C, the AD797 series is necessary. For applications within 0°C to 70°C, both LM318MX/NOPB and AD797 series are suitable.

Q7: How does supply voltage range affect substitute selection?

A: The LM318MX operates at 10V–40V supply voltage. The LM318MX/NOPB maintains this range. The AD797 series operates at 10V–30V. If your circuit requires supply voltages between 30V and 40V, only LM318MX/NOPB is suitable. If your circuit operates within 10V–30V, both LM318MX/NOPB and AD797 series are compatible. Verify your circuit's supply voltage specification before selecting a substitute.

Q8: What is the inventory status of each recommended substitute?

A: LM318MX/NOPB has 12,568 units in stock. AD797ARZ has 15,535 units. AD797ARZ-REEL has 889,288 units (highest availability). AD797ARZ-REEL7 has 16,620 units. AD797BRZ has 3,339 units. AD797BRZ-REEL has 1,993 units. AD797BRZ-REEL7 has 5,121 units. For high-volume production, AD797ARZ-REEL offers the largest available inventory. For smaller quantities, LM318MX/NOPB or AD797ARZ-REEL7 are suitable.

Q9: Are all recommended substitutes RoHS3 Compliant?

A: Yes. LM318MX/NOPB and all AD797 variants are ROHS3 Compliant. The original LM318MX is RoHS non-compliant. If your application or market requires RoHS compliance, use LM318MX/NOPB or any AD797 variant. All substitutes maintain REACH Unaffected and EAR99 export classification status.

Q10: What is the difference between AD797ARZ-REEL and AD797ARZ-REEL7?

A: Both parts are electrically identical with 25 µV input offset voltage. The difference is packaging format: AD797ARZ-REEL is Tape & Reel format, while AD797ARZ-REEL7 is Cut Tape & Digi-Reel format. Tape & Reel is optimized for automated high-speed pick-and-place assembly. Cut Tape & Digi-Reel is suitable for mixed-volume production and manual assembly. Inventory availability differs: AD797ARZ-REEL has 889,288 units, while AD797ARZ-REEL7 has 16,620 units. Select based on assembly process and quantity requirements.