LM4901LD/NOPB Equivalent & Substitute Parts

Part Overview

The LM4901LD/NOPB is a Class AB mono audio amplifier IC manufactured by Texas Instruments, part of the Boomer® series. This device delivers 1.6W output power at 4Ω load and operates across a 2V to 5.5V supply voltage range. The component features depop and shutdown functionality integrated into a 10-WSON (3x4) surface mount package.

The LM4901LD/NOPB is classified as obsolete. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications currently utilizing this amplifier IC.

Substiute Parts

LM4901LD/NOPB

Texas InstrumentsIn Stock: 933LM4901LD/NOPB Datasheet

Current PartRFQ

LM4951SD/NOPB

Texas InstrumentsIn Stock: 35194LM4951SD/NOPB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM4901LD/NOPB is determined by the following critical parameters:

Functional Compatibility Criteria:

• Amplifier topology: Class AB mono configuration
• Manufacturer: Texas Instruments (same design ecosystem)
• Series: Boomer® (same product family)
• Output type: Single-channel (mono) amplifier
• Core features: Depop and shutdown functionality

Electrical Compatibility Criteria:

• Supply voltage range must accommodate the original operating window or extend it
• Output power capability at specified load impedance
• Operating temperature range: -40°C ~ 85°C

Mechanical Compatibility Criteria:

• Surface mount technology
• 10-WSON package family (pin-compatible or functionally equivalent)
• Exposed pad design

Regulatory & Environmental Criteria:

• RoHS3 compliance
• Moisture sensitivity level (MSL): 1 (Unlimited)
• REACH unaffected status

The LM4951SD/NOPB qualifies as a direct substitute based on these parameters.

Parameter Comparison

Engineering Selection Recommendations

LM4951SD/NOPB as Primary Substitute:

The LM4951SD/NOPB is the manufacturer-recommended substitute for the obsolete LM4901LD/NOPB. Both devices share identical core specifications within the Boomer® amplifier family: Class AB topology, mono output configuration, depop and shutdown features, and matching operating temperature range.

Advantages of LM4951SD/NOPB:

• Active product status ensures long-term availability and supply chain continuity
• Extended supply voltage range (2.7V ~ 9V) provides broader application flexibility compared to the original 2V ~ 5.5V specification
• Integrated thermal protection feature enhances reliability in demanding thermal environments
• Higher inventory availability (35,100 pcs in stock versus 862 pcs for the obsolete part)
• Identical RoHS3 compliance and regulatory certifications

Package Consideration: The LM4951SD/NOPB uses a 10-WSON (4x4) package versus the original 10-WSON (3x4). Both are 10-pin WSON packages with exposed pads. PCB layout verification is required to confirm footprint compatibility, as the die size differs between the two variants.

Compliance Status: Both parts maintain ROHS3 compliance, MSL Level 1 (Unlimited), REACH unaffected status, and identical ECCN and HTSUS classifications, ensuring regulatory continuity in production environments.

Frequently Asked Questions (FAQ)

Q: Can the LM4951SD/NOPB directly replace the LM4901LD/NOPB without PCB modifications?

A: Functional substitution is supported. However, the package footprint differs: LM4901LD/NOPB uses 10-WSON (3x4) while LM4951SD/NOPB uses 10-WSON (4x4). PCB layout review is required to confirm pad compatibility and thermal management adequacy before implementation.

Q: What is the difference in output power between these two parts?

A: The LM4901LD/NOPB delivers 1.6W at 4Ω load. The LM4951SD/NOPB delivers 1.8W at 8Ω load. Output power varies with load impedance; direct comparison requires load-specific measurements.

Q: Does the extended supply voltage range of the LM4951SD/NOPB affect circuit design?

A: The LM4951SD/NOPB operates from 2.7V ~ 9V versus the original 2V ~ 5.5V. If your application operates below 2.7V, the substitute is not suitable. For applications within the original 2V ~ 5.5V window, the substitute operates within specification with no design changes required.

Q: What is the significance of thermal protection in the LM4951SD/NOPB?

A: The LM4951SD/NOPB includes integrated thermal protection, an additional feature not present in the LM4901LD/NOPB. This provides automatic shutdown at excessive junction temperatures, enhancing device reliability without requiring external thermal management circuits.

Q: Are both parts RoHS3 compliant?

A: Yes. Both the LM4901LD/NOPB and LM4951SD/NOPB are ROHS3 compliant with identical regulatory certifications (REACH unaffected, EAR99 ECCN, 8542.33.0001 HTSUS).

Q: Why is the LM4951SD/NOPB recommended over other potential substitutes?

A: The LM4951SD/NOPB is the manufacturer-recommended substitute from Texas Instruments. It maintains identical core functionality (Class AB mono amplifier, Boomer® series), matching feature set (depop, shutdown), and operating temperature range, ensuring design continuity with enhanced reliability and supply availability.