LM4905LD/NOPB Equivalent & Substitute Parts

Part Overview

The LM4905LD/NOPB is a Class AB mono audio amplifier IC manufactured by Texas Instruments, part of the Boomer® series. This device delivers 1.07W output power at 8Ω load in a compact 8-WSON (3x3) surface mount package. The product is currently classified as obsolete, necessitating identification of active equivalent alternatives that maintain functional and electrical compatibility for ongoing design support and production requirements.

Substiute Parts

LM4905LD/NOPB

Texas InstrumentsIn Stock: 1440LM4905LD/NOPB Datasheet

Current PartRFQ

LM4879SD/NOPB

Texas InstrumentsIn Stock: 2195LM4879SD/NOPB Datasheet

MFR RecommendedRFQ

TS4990IQT

STMicroelectronicsIn Stock: 26274TS4990IQT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM4905LD/NOPB is determined by the following critical parameters:

Electrical Compatibility Requirements:

• Amplifier topology: Class AB
• Channel configuration: 1-Channel (Mono)
• Supply voltage range: 2.2V ~ 5.5V (must encompass or match)
• Operating temperature range: -40°C ~ 85°C
• Output power capability: minimum 1.07W @ 8Ω load

Mechanical & Packaging Compatibility:

• Mounting type: Surface Mount
• Package footprint: 8-pin DFN/WSON variants with 3x3mm or compatible dimensions
• Exposed pad configuration

Regulatory & Environmental Compliance:

• RoHS3 compliance required
• MSL rating: 1 (Unlimited)

The identified substitute parts meet all electrical parameters within acceptable tolerances and maintain full regulatory compliance. Package variations (8-WSON 4x4 and 8-DFN 3x3) are mechanically compatible with standard PCB design practices for this device class.

Parameter Comparison

Engineering Selection Recommendations

LM4879SD/NOPB (Texas Instruments - Recommended Primary Substitute)

The LM4879SD/NOPB is the manufacturer-recommended direct substitute. It maintains identical electrical specifications and feature set while offering active product status and higher inventory availability (2100 pcs). The package footprint increases from 3x3mm to 4x4mm; this requires PCB layout verification but presents no functional incompatibility. Tape & Reel packaging supports high-volume production requirements.

TS4990IQT (STMicroelectronics - Alternative Substitute)

The TS4990IQT provides cross-manufacturer substitution with superior output power capability (1.2W vs. 1.07W) and enhanced feature integration including differential inputs and standby mode. The 8-DFN (3x3) package maintains the original footprint dimensions, eliminating PCB redesign requirements. Exceptional inventory availability (26200 pcs) supports supply chain continuity. This option is suitable for applications requiring extended feature functionality.

Both substitutes satisfy all regulatory compliance requirements (ROHS3, MSL-1) and maintain the full operating temperature range of the original device.

Frequently Asked Questions (FAQ)

Q: Can the LM4879SD/NOPB replace the LM4905LD/NOPB without PCB modifications?

A: The LM4879SD/NOPB requires PCB layout verification due to package size increase from 8-WSON (3x3) to 8-WSON (4x4). Pin configuration remains compatible; however, the larger footprint may necessitate minor layout adjustments. Pinout compatibility must be confirmed against your specific schematic.

Q: What is the primary advantage of the TS4990IQT substitute?

A: The TS4990IQT maintains the original 3x3mm package footprint, eliminating PCB redesign. It delivers 1.2W output power (12% higher than the original 1.07W specification) and includes differential input capability and standby mode functionality. Supply availability is significantly higher at 26200 pcs.

Q: Are all three devices pin-compatible?

A: All three devices are 8-pin configurations with identical electrical pin assignments for audio amplifier operation. Physical package dimensions differ (3x3mm vs. 4x4mm vs. 3x3mm), requiring footprint verification during PCB layout.

Q: Do the substitute parts maintain the same thermal protection characteristics?

A: Yes. All three devices include thermal protection as a core feature. The LM4879SD/NOPB and TS4990IQT maintain identical thermal management specifications to the LM4905LD/NOPB.

Q: What is the impact of the TS4990IQT's differential inputs feature?

A: Differential inputs provide enhanced noise rejection and signal integrity compared to single-ended input configurations. This feature is transparent to existing single-ended designs but enables improved performance in noise-sensitive applications without circuit modification.

Q: Are moisture sensitivity levels identical across all three parts?

A: Yes. All three devices carry MSL rating 1 (Unlimited), indicating no moisture sensitivity restrictions during storage, handling, or assembly processes.

Q: Which substitute offers the best supply chain continuity?

A: The TS4990IQT provides the highest inventory availability at 26200 pcs, followed by LM4879SD/NOPB at 2100 pcs. Both are active products with ongoing manufacturing support.