LM6181IM Equivalent & Substitute Parts

Part Overview

The LM6181IM is a Current Feedback Amplifier manufactured by Texas Instruments, housed in a 16-SOIC package. This device is classified as obsolete, necessitating identification of active equivalent and substitute components for ongoing design requirements and production continuity. The LM6181IM operates across a wide supply voltage range (7V to 32V) with a slew rate of 2000V/µs and -3dB bandwidth of 100 MHz, making it suitable for high-speed signal conditioning applications.

Substiute Parts

LM6181IM

Texas InstrumentsIn Stock: 2745LM6181IM Datasheet

Current PartRFQ

OPA694ID

Texas InstrumentsIn Stock: 1697OPA694ID Datasheet

MFR RecommendedRFQ

ISL28177FBZ

Renesas Electronics CorporationIn Stock: 1367ISL28177FBZ Datasheet

MFR RecommendedRFQ

ISL28177FBZ-T13

Renesas Electronics CorporationIn Stock: 2530ISL28177FBZ-T13 Datasheet

MFR RecommendedRFQ

ISL28177FBZ-T7

Renesas Electronics CorporationIn Stock: 1925ISL28177FBZ-T7 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM6181IM requires evaluation based on the following critical parameters:

Functional Compatibility Criteria:

• Amplifier Type: Current Feedback architecture
• Number of Circuits: Single circuit configuration
• Operating Temperature Range: -40°C to 85°C minimum
• Supply Voltage Range: Minimum 7V to maximum 32V overlap
• Slew Rate: 2000V/µs or higher
• Bandwidth: 100 MHz or higher

Package Compatibility:

• Surface Mount technology
• SOIC package family (pin count and pitch compatibility)

Compliance Requirements:

• RoHS3 Compliant
• REACH Unaffected status

The identified substitute parts fall into two functional categories:

1. Direct Current Feedback Amplifier Substitute (OPA694ID): Active product with current feedback architecture, higher bandwidth (1.5 GHz), and comparable slew rate (1700V/µs). Package differs (8-SOIC vs. 16-SOIC), requiring PCB layout modification.

2. General Purpose Amplifier Substitutes (ISL28177FBZ, ISL28177FBZ-T13, ISL28177FBZ-T7): Active products with general purpose amplifier architecture, lower slew rate (0.2V/µs), and extended supply voltage range (6V to 40V). These represent functional alternatives with different performance characteristics and packaging options (Tube vs. Tape & Reel).

Parameter Comparison

Engineering Selection Recommendations

OPA694ID Selection Criteria:

The OPA694ID is an active current feedback amplifier from Texas Instruments, maintaining architectural compatibility with the LM6181IM. This substitute is appropriate when:

• Current feedback amplifier topology is required for the application
• Higher bandwidth performance (1.5 GHz vs. 100 MHz) is acceptable or beneficial
• Supply voltage operation within 7V to 12.6V range is feasible
• Output current requirement does not exceed 80 mA
• PCB redesign to accommodate 8-SOIC package (vs. 16-SOIC) is permissible
• Moisture sensitivity level MSL 2 (1 Year) storage requirements are manageable

ISL28177FBZ / ISL28177FBZ-T13 / ISL28177FBZ-T7 Selection Criteria:

The ISL28177 series (Renesas Electronics) represents general purpose amplifier alternatives with extended supply voltage range (6V to 40V) and superior input offset voltage (150 µV vs. 3.5 mV). These substitutes are appropriate when:

• General purpose amplifier architecture meets application requirements
• Extended supply voltage range (up to 40V) is advantageous
• Lower input offset voltage and input bias current improve signal fidelity
• Reduced slew rate (0.2V/µs vs. 2000V/µs) is acceptable for the application
• Lower output current capability (30 mA vs. 130 mA) is sufficient
• Extended operating temperature range (-40°C to 125°C) provides additional margin
• Packaging format selection between Tube (ISL28177FBZ) or Tape & Reel (ISL28177FBZ-T13, ISL28177FBZ-T7) aligns with production requirements
• Unlimited moisture sensitivity level (MSL 1) is preferred

All substitute parts maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory continuity.

Frequently Asked Questions (FAQ)

Q1: Can OPA694ID directly replace LM6181IM without circuit modification?

A: OPA694ID differs in package (8-SOIC vs. 16-SOIC), supply voltage maximum (12.6V vs. 32V), and output current capability (80 mA vs. 130 mA). PCB layout modification is required. Circuit validation is necessary to confirm compatibility with existing supply voltage and load current specifications.

Q2: What are the key performance differences between OPA694ID and ISL28177 series?

A: OPA694ID maintains current feedback amplifier architecture with 1.5 GHz bandwidth and 1700V/µs slew rate. ISL28177 series uses general purpose amplifier architecture with 600 kHz gain bandwidth product and 0.2V/µs slew rate. Selection depends on whether high-speed current feedback characteristics or extended supply voltage range is prioritized.

Q3: Are ISL28177FBZ, ISL28177FBZ-T13, and ISL28177FBZ-T7 functionally identical?

A: These three parts are functionally identical. The differences are packaging format only: ISL28177FBZ is supplied in Tube packaging, while ISL28177FBZ-T13 and ISL28177FBZ-T7 are supplied in Tape & Reel format. Selection is based on production assembly requirements and inventory management preferences.

Q4: What is the impact of reduced slew rate in ISL28177 series compared to LM6181IM?

A: LM6181IM provides 2000V/µs slew rate while ISL28177 series provides 0.2V/µs. This 10,000x reduction limits ISL28177 suitability to applications with slower signal transitions. High-frequency or fast transient applications require OPA694ID or equivalent current feedback amplifier.

Q5: How does supply voltage range affect substitution selection?

A: LM6181IM operates from 7V to 32V. OPA694ID operates from 7V to 12.6V, limiting use in high-voltage applications. ISL28177 series operates from 6V to 40V, providing extended range capability. Supply voltage compatibility with existing power distribution must be verified before substitution.

Q6: What are the moisture sensitivity implications for long-term storage?

A: LM6181IM and ISL28177 series have MSL 1 (Unlimited), allowing indefinite storage without moisture control. OPA694ID has MSL 2 (1 Year), requiring controlled storage environment or baking before assembly if storage exceeds one year. Production scheduling and inventory management must account for this difference.

Q7: Does package size reduction from 16-SOIC to 8-SOIC affect circuit performance?

A: Package size reduction does not inherently affect electrical performance. However, 8-SOIC packaging provides fewer pins, potentially limiting design flexibility. PCB layout, trace routing, and thermal management may differ. Circuit schematic validation is required to confirm pin compatibility and functionality.

Q8: Are all substitute parts RoHS3 compliant?

A: Yes. LM6181IM, OPA694ID, ISL28177FBZ, ISL28177FBZ-T13, and ISL28177FBZ-T7 are all ROHS3 Compliant with REACH Unaffected status, ensuring regulatory compliance for current manufacturing and distribution requirements.