LP3944ISQX LED Driver IC Equivalent & Substitute Parts

Part Overview

The LP3944ISQX is an 8-output LED driver IC manufactured by Texas Instruments, designed for power switch applications with I2C/SMBus dimming control. This device integrates a shift register topology with internal power switches, delivering 25mA per output channel across a 2.3V to 5.5V supply range. The LP3944ISQX is classified as obsolete, which necessitates identification of active equivalent parts for new designs and ongoing production requirements. Substitute parts maintain identical electrical and mechanical specifications while offering improved product status and compliance certifications.

Substiute Parts

LP3944ISQX

Texas InstrumentsIn Stock: 5958LP3944ISQX Datasheet

Current PartRFQ

LP3944ISQX/NOPB

Texas InstrumentsIn Stock: 1814LP3944ISQX/NOPB Datasheet

DirectRFQ

LP3944ISQ/NOPB

Texas InstrumentsIn Stock: 25301LP3944ISQ/NOPB Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LP3944ISQX are identified based on strict parameter matching across electrical and mechanical specifications. The substitution logic is based on the following critical parameters:

• Number of outputs: 8 channels
• Output current capability: 25mA per channel
• Supply voltage range: 2.3V to 5.5V
• Control interface: I2C/SMBus dimming
• Package type: 24-WQFN (4x4) with exposed pad
• Mounting: Surface mount
• Operating temperature range: -40°C to 85°C
• Internal topology: Shift register with power switches

Two substitute parts meet these criteria: LP3944ISQX/NOPB (direct manufacturer equivalent with improved compliance) and LP3944ISQ/NOPB (parametric equivalent with active product status and higher inventory availability).

Parameter Comparison

Engineering Selection Recommendations

The LP3944ISQX is obsolete and non-compliant with RoHS3 standards. For new designs and production continuity, LP3944ISQ/NOPB is the primary selection due to active product status, ROHS3 compliance, and significantly higher inventory availability (25200 units). This part maintains all electrical and mechanical specifications identical to the original LP3944ISQX.

LP3944ISQX/NOPB serves as a secondary option, offering direct manufacturer equivalence with ROHS3 compliance and active product status. However, inventory levels are lower (1720 units) compared to LP3944ISQ/NOPB.

Both substitute parts are supplied in Tape & Reel packaging, which is standard for production environments and differs from the bulk packaging of the obsolete LP3944ISQX.

Frequently Asked Questions (FAQ)

Q: Can LP3944ISQ/NOPB directly replace LP3944ISQX in existing designs?

A: Yes. All electrical parameters, pin configurations, package dimensions, and functional specifications are identical. The part is pin-compatible and functionally equivalent for all applications.

Q: What is the difference between LP3944ISQX/NOPB and LP3944ISQ/NOPB?

A: Both parts are parametric equivalents with identical electrical and mechanical specifications. The primary differences are packaging format (both Tape & Reel) and inventory availability. LP3944ISQ/NOPB has higher stock levels and is recommended for production orders.

Q: Why is the original LP3944ISQX marked as obsolete?

A: The LP3944ISQX has been discontinued by Texas Instruments. Active equivalent parts (LP3944ISQ/NOPB and LP3944ISQX/NOPB) are available as direct replacements.

Q: Are the substitute parts RoHS compliant?

A: Yes. Both LP3944ISQ/NOPB and LP3944ISQX/NOPB are ROHS3 compliant, whereas the original LP3944ISQX is RoHS non-compliant.

Q: What is the packaging difference between the original and substitute parts?

A: The original LP3944ISQX is supplied in bulk packaging. Both substitute parts (LP3944ISQ/NOPB and LP3944ISQX/NOPB) are supplied in Tape & Reel (TR) format, which is standard for automated assembly processes.

Q: Are there any thermal or electrical performance differences?

A: No. All thermal characteristics, electrical performance parameters, and operating ranges are identical across all three part numbers.

Q: Which substitute part should be selected for new production?

A: LP3944ISQ/NOPB is recommended for new production due to active product status, ROHS3 compliance, and superior inventory availability (25200 units in stock).