LM4891M/NOPB Equivalent & Substitute Parts

Part Overview

The LM4891M/NOPB is a Class AB mono audio power amplifier IC manufactured by Texas Instruments, designed to deliver 1W output power at 8Ohm load in a compact 8-SOIC surface mount package. This device is classified as Obsolete, necessitating identification of equivalent and substitute components for ongoing production and maintenance applications. The part operates across a 2.2V to 5.5V supply voltage range and includes integrated depop, shutdown, and thermal protection features. Due to its obsolete status, active alternative components with compatible electrical and mechanical specifications are required for design continuity.

Substiute Parts

LM4891M/NOPB

Texas InstrumentsIn Stock: 1224LM4891M/NOPB Datasheet

Current PartRFQ

LM4889MA/NOPB

National SemiconductorIn Stock: 1301LM4889MA/NOPB Datasheet

MFR RecommendedRFQ

TPA741DR

Texas InstrumentsIn Stock: 1424TPA741DR Datasheet

MFR RecommendedRFQ

MAX4364ESA+

Analog Devices Inc./Maxim IntegratedIn Stock: 16214MAX4364ESA+ Datasheet

MFR RecommendedRFQ

MAX4364ESA+T

Analog Devices Inc./Maxim IntegratedIn Stock: 1405MAX4364ESA+T Datasheet

MFR RecommendedRFQ

NCS2211DR2G

onsemiIn Stock: 20167NCS2211DR2G Datasheet

MFR RecommendedRFQ

TPA741D

Texas InstrumentsIn Stock: 1476TPA741D Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM4891M/NOPB is determined by the following critical parameters:

Primary Compatibility Criteria:

• Package Type: 8-SOIC form factor (0.154", 3.90mm Width)
• Mounting Type: Surface Mount
• Output Configuration: 1-Channel (Mono) Class AB amplifier
• Operating Temperature Range: -40°C ~ 85°C (TA)
• Supply Voltage Range: Minimum 2.2V to 5.5V maximum
• Output Power Capability: Minimum 1W at 8Ohm load

Substitution Logic: Substitute parts must maintain identical package geometry and mounting characteristics to ensure PCB compatibility without layout modifications. All candidates operate within the same temperature range and share Class AB amplifier topology. Supply voltage ranges must encompass or exceed the original 2.2V to 5.5V specification. Output power ratings at 8Ohm load must meet or exceed 1W to ensure functional equivalence. All substitute parts maintain ROHS3 compliance and MSL Level 1 rating, ensuring environmental and handling compatibility.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute - LM4889MA/NOPB: The LM4889MA/NOPB from National Semiconductor is the manufacturer-recommended direct substitute. It maintains identical electrical specifications (1W @ 8Ohm, 2.2V to 5.5V supply), matching package geometry, and equivalent feature set including depop, shutdown, and thermal protection. Product status is Active, ensuring long-term availability. This part is the preferred choice for direct replacement in existing designs.

Secondary Substitutes - TPA741DR / TPA741D: The TPA741DR and TPA741D from Texas Instruments are functionally compatible alternatives with identical package and temperature specifications. Output power is rated at 700mW @ 8Ohm, which is lower than the original 1W specification. Supply voltage range begins at 2.5V (versus 2.2V minimum for LM4891M/NOPB), creating a potential constraint in applications requiring operation below 2.5V. Both variants are Active products with ROHS3 compliance. Selection of these parts requires confirmation that 700mW output power is sufficient for the application and that minimum supply voltage of 2.5V is acceptable.

Alternative Substitutes - MAX4364ESA+ / MAX4364ESA+T: The MAX4364ESA+ and MAX4364ESA+T from Analog Devices Inc./Maxim Integrated offer higher output power (1.4W @ 8Ohm) within the same 8-SOIC package. Supply voltage range is 2.7V to 5.5V, establishing a 2.7V minimum constraint. Both parts are classified as Not For New Designs, indicating limited future availability and unsuitability for new product development. These parts are suitable only for legacy system maintenance where existing inventory exists.

Alternative Substitute - NCS2211DR2G: The NCS2211DR2G from onsemi is an Active product with higher output power capability (1.5W @ 4Ohm). This part differs in load impedance specification, with output power rated at 4Ohm rather than 8Ohm. Supply voltage range is 2.7V to 5.5V. Selection requires confirmation that the application load impedance is compatible with the 4Ohm specification and that 2.7V minimum supply voltage is acceptable.

Compliance and Availability: All substitute parts maintain ROHS3 compliance and MSL Level 1 rating. The LM4889MA/NOPB and TPA741 variants (Active status) are recommended for new applications and ongoing production. MAX4364 variants should be limited to legacy support only. NCS2211DR2G is suitable for applications with 4Ohm load impedance requirements.

Frequently Asked Questions (FAQ)

Q: Can the LM4891M/NOPB be directly replaced with the LM4889MA/NOPB without PCB modifications?

A: Yes. The LM4889MA/NOPB maintains identical 8-SOIC package dimensions (0.154", 3.90mm Width), pin configuration, and electrical specifications. No PCB layout changes are required for direct substitution.

Q: What is the primary difference between TPA741DR and TPA741D?

A: Both parts are electrically identical Class AB mono amplifiers with 700mW output power at 8Ohm. The difference is packaging format: TPA741DR is supplied in Cut Tape (CT) & Digi-Reel format, while TPA741D is supplied in Tube format. Selection depends on assembly process requirements.

Q: Can the TPA741 series be used as a substitute if the application requires 1W output power?

A: The TPA741 series is rated for 700mW @ 8Ohm, which is below the 1W specification of the LM4891M/NOPB. Substitution is not recommended for applications requiring 1W output power. The LM4889MA/NOPB or MAX4364 variants are appropriate for 1W+ requirements.

Q: Why are MAX4364ESA+ and MAX4364ESA+T marked as "Not For New Designs"?

A: This designation indicates that these parts are in mature or declining production phases. While currently available, manufacturers do not recommend their use in new product designs due to potential future discontinuation. These parts are suitable only for maintaining existing products or legacy system support.

Q: What is the significance of the NCS2211DR2G output power being specified at 4Ohm instead of 8Ohm?

A: The NCS2211DR2G is rated for 1.5W @ 4Ohm load impedance, whereas the LM4891M/NOPB is rated for 1W @ 8Ohm. These represent different load conditions. The NCS2211DR2G is suitable only for applications with 4Ohm speaker or load impedance. Direct substitution in 8Ohm applications requires verification that the part delivers adequate power at 8Ohm load.

Q: Are all substitute parts ROHS3 compliant?

A: All substitute parts listed are ROHS3 compliant. The LM4891M/NOPB original part is also ROHS3 compliant, ensuring environmental regulation consistency across all options.

Q: What is the minimum supply voltage constraint when selecting between substitutes?

A: The LM4891M/NOPB operates from 2.2V minimum. The LM4889MA/NOPB maintains this 2.2V minimum. TPA741 variants require 2.5V minimum, and MAX4364 and NCS2211 variants require 2.7V minimum. Applications operating below 2.5V must use LM4891M/NOPB or LM4889MA/NOPB.

Q: Is the Boomer® series designation important for substitution?

A: The Boomer® series designation applies to LM4891M/NOPB and LM4889MA/NOPB. This is a product line identifier from Texas Instruments and National Semiconductor. Other substitute parts (TPA741, MAX4364, NCS2211) are not part of the Boomer series but are functionally equivalent Class AB mono amplifiers. Series designation does not affect electrical compatibility.

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

A: LM4889MA/NOPB is supplied in Bulk format. TPA741DR is supplied in Cut Tape (CT) & Digi-Reel format, while TPA741D is supplied in Tube format. MAX4364ESA+ is supplied in Tube format, and MAX4364ESA+T is supplied in Cut Tape (CT) & Digi-Reel format. NCS2211DR2G is supplied in Cut Tape (CT) & Digi-Reel format. Selection depends on assembly process and quantity requirements.