OPA642N/3K Equivalent & Substitute Parts

Part Overview

The OPA642N/3K is a voltage feedback operational amplifier manufactured by Texas Instruments, housed in a SOT-23-5 surface mount package. This device is classified as obsolete, indicating discontinued production and limited availability. The OPA642N/3K delivers a gain bandwidth product of 210 MHz with a slew rate of 380 V/µs, designed for single-supply operation across a 9 V to 11 V range. Due to its obsolete status and finite inventory, identifying equivalent substitute components is essential for design continuity and procurement planning.

Substiute Parts

OPA642N/3K

Texas InstrumentsIn Stock: 3569OPA642N/3K Datasheet

Current PartRFQ

LT1815CS5#TRMPBF

Analog Devices Inc.In Stock: 2232LT1815CS5#TRMPBF Datasheet

MFR RecommendedRFQ

LT1815IS5#TRMPBF

Analog Devices Inc.In Stock: 2467LT1815IS5#TRMPBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the OPA642N/3K is determined by electrical and mechanical compatibility across the following critical parameters:

Electrical Compatibility Criteria:

• Amplifier topology: Voltage feedback configuration
• Single circuit per package
• Gain bandwidth product: Minimum 210 MHz
• Slew rate: Minimum 380 V/µs
• Input bias current: Maximum 25 µA
• Input offset voltage: Maximum 1.5 mV
• Output current capability: Minimum 60 mA per channel
• Supply voltage range: Minimum 9 V to 11 V overlap

Mechanical Compatibility Criteria:

• Surface mount package type
• SOT-23-5 or equivalent pinout compatibility
• Moisture sensitivity level: 1 (Unlimited)

The substitute parts LT1815CS5#TRMPBF and LT1815IS5#TRMPBF, both manufactured by Analog Devices Inc., meet or exceed all electrical parameters of the OPA642N/3K while maintaining mechanical compatibility through identical SOT-23-5 package geometry and pinout.

Parameter Comparison

Engineering Selection Recommendations

LT1815IS5#TRMPBF is the primary substitute for the OPA642N/3K. This device maintains full electrical compatibility with superior performance characteristics across all critical parameters. The LT1815IS5#TRMPBF operates across the complete temperature range of -40°C to 85°C, matching the OPA642N/3K specification. The part is actively manufactured by Analog Devices Inc., ensuring long-term availability and supply chain stability. ROHS3 compliance provides regulatory advantage for new designs and procurement cycles.

LT1815CS5#TRMPBF serves as a secondary substitute with identical electrical performance but operates within a restricted temperature range of 0°C to 70°C. This device is suitable for applications where the full -40°C to 85°C operating range is not required. Both LT1815 variants deliver superior electrical performance, including 1500 V/µs slew rate (3.95× improvement), 220 MHz gain bandwidth product (1.05× improvement), and significantly reduced input bias current and offset voltage.

Both substitute parts are supplied in Tape & Reel packaging, compatible with automated assembly processes. The TSOT-23-5 package maintains mechanical and electrical pinout equivalence with the OPA642N/3K SOT-23-5 package.

Frequently Asked Questions (FAQ)

Q: Can LT1815CS5#TRMPBF and LT1815IS5#TRMPBF be used interchangeably with OPA642N/3K?

A: Both LT1815 variants are electrically compatible with the OPA642N/3K. The primary difference is operating temperature range. LT1815IS5#TRMPBF covers -40°C to 85°C (full range match), while LT1815CS5#TRMPBF covers 0°C to 70°C (restricted range). Select based on application temperature requirements.

Q: What are the key electrical improvements of the LT1815 series over the OPA642N/3K?

A: The LT1815 series provides superior performance: slew rate increases from 380 V/µs to 1500 V/µs, input bias current decreases from 25 µA to 2 µA, and input offset voltage decreases from 1.5 mV to 0.2 mV. Gain bandwidth product increases marginally from 210 MHz to 220 MHz.

Q: Are the package dimensions identical between OPA642N/3K and LT1815 substitutes?

A: Both devices use SOT-23-5 surface mount packages with identical pinout. The LT1815 uses TSOT-23-5 (thin variant), which maintains mechanical compatibility with standard SOT-23-5 footprints. No PCB layout modifications are required.

Q: What is the supply voltage compatibility between these devices?

A: The OPA642N/3K operates at 9 V to 11 V. The LT1815 series operates at 2.5 V to 11 V, providing broader supply voltage flexibility. Both devices are compatible within the OPA642N/3K supply range.

Q: Does RoHS compliance affect substitution decisions?

A: The OPA642N/3K is RoHS non-compliant, while both LT1815 variants are ROHS3 compliant. For new designs or procurement requiring RoHS compliance, the LT1815 series is the appropriate choice. For legacy systems, either part is acceptable based on regulatory requirements.

Q: What is the inventory status of these substitute parts?

A: LT1815IS5#TRMPBF has 2409 pieces in stock, and LT1815CS5#TRMPBF has 2180 pieces in stock. Both are actively manufactured and available through standard distribution channels.