LM321MF Equivalent & Substitute Parts

Part Overview

The LM321MF is a general-purpose operational amplifier manufactured by Texas Instruments in a SOT-23-5 surface mount package. This single-circuit amplifier is designed for applications requiring low-power operation with a supply voltage range of 3V to 30V and operating temperature range of -40°C to 85°C. The LM321MF carries a Last Time Buy product status, indicating discontinued production. Identifying equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain reliability for ongoing production and maintenance applications.

Substiute Parts

LM321MF

Texas InstrumentsIn Stock: 24284LM321MF Datasheet

Current PartRFQ

LM321MF/NOPB

Texas InstrumentsIn Stock: 28956LM321MF/NOPB Datasheet

DirectRFQ

LM321MFX/NOPB

Texas InstrumentsIn Stock: 65392LM321MFX/NOPB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM321MF is determined by electrical and mechanical parameter equivalence across the following critical criteria:

Electrical Parameters (Must Match):

• Amplifier Type: General Purpose
• Number of Circuits: 1
• Slew Rate: 0.4 V/µs
• Gain Bandwidth Product: 1 MHz
• Current - Input Bias: 45 nA
• Voltage - Input Offset: 2 mV
• Current - Supply: 660 µA
• Current - Output / Channel: 40 mA
• Operating Temperature Range: -40°C to 85°C

Mechanical Parameters (Must Match):

• Mounting Type: Surface Mount
• Package / Case: SC-74A, SOT-753
• Supplier Device Package: SOT-23-5

Supply Voltage Compatibility:

• Minimum supply voltage must be ≤ 3V
• Maximum supply voltage must be ≥ 30V

The substitute parts LM321MF/NOPB and LM321MFX/NOPB satisfy all electrical and mechanical equivalence criteria. Both parts maintain identical functional specifications and package configurations, enabling direct substitution in circuit designs.

Parameter Comparison

Engineering Selection Recommendations

LM321MF/NOPB is the direct manufacturer-designated substitute for the LM321MF. This part maintains identical electrical and mechanical specifications while offering Active product status, ensuring continued availability and supply chain stability. The LM321MF/NOPB carries REACH Unaffected compliance status, providing regulatory advantage over the original LM321MF.

LM321MFX/NOPB is the manufacturer-recommended alternative, designated as the preferred long-term solution. This part extends the maximum supply voltage specification to 32V (compared to 30V for LM321MF), providing enhanced voltage margin in applications operating near the upper supply limit. The LM321MFX/NOPB maintains all other electrical parameters identically and carries Active product status with REACH Unaffected compliance.

Both substitute parts are suitable for direct replacement in existing LM321MF circuit designs without modification. Selection between LM321MF/NOPB and LM321MFX/NOPB depends on application supply voltage requirements and long-term availability preferences.

Frequently Asked Questions (FAQ)

Q: Can LM321MF/NOPB be used as a direct replacement for LM321MF?

A: Yes. LM321MF/NOPB is electrically and mechanically equivalent to LM321MF across all specified parameters. Both parts share identical slew rate (0.4 V/µs), gain bandwidth product (1 MHz), input bias current (45 nA), input offset voltage (2 mV), supply current (660 µA), output current (40 mA), supply voltage range (3V to 30V), operating temperature range (-40°C to 85°C), and SOT-23-5 package configuration.

Q: What is the difference between LM321MF/NOPB and LM321MFX/NOPB?

A: The primary difference is the maximum supply voltage specification. LM321MFX/NOPB supports a maximum supply voltage of 32V, while LM321MF/NOPB supports 30V. All other electrical and mechanical parameters are identical. Both parts are Active status products with REACH Unaffected compliance.

Q: Why is the LM321MF marked as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has discontinued production of the LM321MF. Existing inventory is available for purchase, but no future production is planned. LM321MF/NOPB and LM321MFX/NOPB are Active status alternatives that ensure continued supply availability.

Q: Are there any compliance differences between the substitute parts and the original LM321MF?

A: Yes. The original LM321MF carries REACH Affected status, while both LM321MF/NOPB and LM321MFX/NOPB carry REACH Unaffected status. All three parts are ROHS3 Compliant with MSL 1 (Unlimited) moisture sensitivity rating.

Q: Can LM321MFX/NOPB be used in applications designed for LM321MF?

A: Yes. LM321MFX/NOPB is fully compatible with LM321MF circuit designs. The extended maximum supply voltage (32V vs. 30V) provides additional operational margin and does not create incompatibility with existing designs. No circuit modifications are required.

Q: What packaging formats are available for the substitute parts?

A: Both LM321MF/NOPB and LM321MFX/NOPB are available in Cut Tape (CT) and Digi-Reel® packaging formats. The physical package is SC-74A, SOT-753 (SOT-23-5 supplier device package), identical to the original LM321MF.

Q: Are the substitute parts suitable for high-temperature applications?

A: Yes. Both LM321MF/NOPB and LM321MFX/NOPB maintain the operating temperature range of -40°C to 85°C, identical to the original LM321MF. This range is suitable for industrial and automotive applications within the specified temperature limits.