TLC5949DBQ LED Driver IC Equivalent & Substitute Parts

Part Overview

The TLC5949DBQ is a 16-output linear LED driver IC manufactured by Texas Instruments, designed for shift register-based PWM dimming applications in signage systems. The device features 45mA per-channel output capability and operates across a 3V to 3.6V supply range. This part is currently classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production support.

Substiute Parts

TLC5949DBQ

Texas InstrumentsIn Stock: 1222TLC5949DBQ Datasheet

Current PartRFQ

LED1642GWXTTR

STMicroelectronicsIn Stock: 2370LED1642GWXTTR Datasheet

MFR RecommendedRFQ

PCA9685BS,118

NXP USA Inc.In Stock: 5325PCA9685BS,118 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the TLC5949DBQ is determined by the following critical parameters:

• Number of Outputs: Must be 16 outputs to maintain circuit compatibility
• Dimming Capability: Must support PWM dimming for functional equivalence
• Topology: Must be linear shift register-based architecture
• Internal Switching: Must include internal switches
• Operating Temperature Range: Must support -40°C ~ 85°C minimum
• Supply Voltage Compatibility: Substitute must operate within or encompass the 3V to 3.6V range
• Output Current: Substitute must meet or exceed 45mA per-channel requirement for direct replacement
• Mounting Type: Surface mount packages only
• Compliance: ROHS3 compliant and REACH unaffected status required

The identified substitute parts meet these core substitution criteria while offering extended supply voltage ranges and active product status.

Parameter Comparison

Engineering Selection Recommendations

LED1642GWXTTR (STMicroelectronics): This substitute provides the closest functional match to the TLC5949DBQ. It maintains 16 outputs, linear shift register topology, and PWM dimming capability across the required -40°C to 85°C operating range. The part is currently in active production status with ROHS3 compliance. The output current specification of 40mA is slightly lower than the original 45mA; applications requiring the full 45mA per-channel must be evaluated for current margin. The extended supply voltage range (3V to 5.5V) provides broader system compatibility. Package transition from 24-SSOP to 24-TSSOP-EP requires PCB layout modification.

PCA9685BS,118 (NXP USA Inc.): This substitute offers 16 outputs with PWM dimming and operates across -40°C to 85°C. The part is in active production with ROHS3 compliance. The output current specification of 25mA is significantly lower than the original 45mA and is suitable only for applications with reduced current requirements. The extended supply voltage range (2.3V to 5.5V) provides maximum system flexibility. Package transition to 28-HVQFN (6x6) requires significant PCB redesign and is recommended only when current reduction is acceptable.

Both substitute parts are ROHS3 compliant and REACH unaffected, meeting regulatory requirements equivalent to the original part.

Frequently Asked Questions (FAQ)

Q: Can the LED1642GWXTTR directly replace the TLC5949DBQ without circuit modification?

A: The LED1642GWXTTR maintains functional equivalence in output count, topology, and dimming capability. However, the 40mA per-channel output versus the original 45mA requires current margin verification for your specific application. Package differences (24-SSOP to 24-TSSOP-EP) necessitate PCB layout changes.

Q: What is the primary limitation of the PCA9685BS,118 as a substitute?

A: The PCA9685BS,118 provides only 25mA per-channel output current, which is 44% lower than the TLC5949DBQ specification of 45mA. This substitute is suitable only for applications with reduced current demands. The 28-HVQFN package also requires substantial PCB redesign.

Q: Are both substitute parts suitable for signage applications?

A: The LED1642GWXTTR is specified for signage applications and is the preferred substitute. The PCA9685BS,118 is specified for backlight applications; use in signage requires application-specific current and thermal analysis.

Q: Do the substitute parts support the same supply voltage as the original TLC5949DBQ?

A: Both substitutes support the 3V to 3.6V range of the original part. Both also extend the maximum supply voltage to 5.5V, providing additional system design flexibility.

Q: What are the package considerations for substitution?

A: The TLC5949DBQ uses 24-SSOP packaging. The LED1642GWXTTR uses 24-TSSOP-EP (similar footprint with exposed pad), requiring minor PCB modifications. The PCA9685BS,118 uses 28-HVQFN (6x6), requiring complete PCB redesign and is not recommended for direct substitution without significant engineering effort.

Q: Are both substitute parts ROHS3 compliant?

A: Yes, both the LED1642GWXTTR and PCA9685BS,118 are ROHS3 compliant and REACH unaffected, meeting the same regulatory requirements as the original TLC5949DBQ.