RT8475GS LED Driver Controller - Equivalent & Substitute Parts

Part Overview

The RT8475GS is a LED Driver Controller IC manufactured by Richtek USA Inc., designed for power management applications requiring step-down (buck) and step-up (boost) topologies. This device operates across a 4.5V to 36V supply range with a 350kHz switching frequency and supports both analog and PWM dimming for backlight and lighting applications.

The RT8475GS carries a "Not For New Designs" product status, indicating it is in mature or end-of-life phase. Identifying equivalent and substitute parts is essential for ongoing production support, design continuity, and supply chain resilience. The substitute parts listed below maintain functional compatibility within the LED driver controller category while offering active product status and alternative packaging options.

Substiute Parts

RT8475GS

Richtek USA Inc.In Stock: 1051RT8475GS Datasheet

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AT9933LG-G

Microchip TechnologyIn Stock: 3335AT9933LG-G Datasheet

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HVLED002TR

STMicroelectronicsIn Stock: 2870HVLED002TR Datasheet

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LT3755IMSE-1#PBF

Analog Devices Inc.In Stock: 20179LT3755IMSE-1#PBF Datasheet

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LT3796EFE-1#PBF

Analog Devices Inc.In Stock: 2764LT3796EFE-1#PBF Datasheet

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LT8391AEFE#PBF

Analog Devices Inc.In Stock: 998LT8391AEFE#PBF Datasheet

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MAX16831ATJ+

Analog Devices Inc./Maxim IntegratedIn Stock: 1079MAX16831ATJ+ Datasheet

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MP4013GS

Monolithic Power Systems Inc.In Stock: 1063MP4013GS Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution logic for the RT8475GS is based on the following critical parameters that define functional equivalence:

Primary Substitution Criteria:

• Type: DC DC Controller
• Topology: Step-Down (Buck), Step-Up (Boost) capability
• Number of Outputs: 1
• Dimming Support: Analog, PWM or PWM-only
• Internal Switch(s): No (external switch configuration)
• RoHS3 Compliance: Required
• Operating Temperature Range: -40°C minimum and 125°C maximum

Secondary Compatibility Factors:

• Supply Voltage Range: Overlap with 4.5V to 36V input specification
• Switching Frequency: 100kHz to 2MHz range acceptable for LED driver applications
• Package Type: Surface mount variants (SOIC, TSSOP, TQFN, MSOP)
• Mounting Compatibility: All substitutes are surface mount

The substitute parts are grouped into two categories based on product maturity and availability:

Active Status Substitutes (Recommended for new designs and ongoing production):

• AT9933LG-G (Microchip Technology) - 8-SOIC package, automotive qualified
• LT3755IMSE-1#PBF (Analog Devices Inc.) - 16-MSOP-EP package, extended topology support
• LT3796EFE-1#PBF (Analog Devices Inc.) - 28-TSSOP-EP package, high voltage capability
• LT8391AEFE#PBF (Analog Devices Inc.) - 28-TSSOP-EP package, automotive grade
• MAX16831ATJ+ (Analog Devices Inc./Maxim Integrated) - 32-TQFN package, automotive qualified
• MP4013GS (Monolithic Power Systems Inc.) - 16-SOIC package, automotive grade

Active Status Alternative (Different package, functional compatibility):

• HVLED002TR (STMicroelectronics) - 8-SOIC package, narrower voltage range (7V-25V)

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Minimal Design Changes):

MP4013GS is the closest functional equivalent to RT8475GS. Both devices feature 16-pin SOIC packaging, support analog and PWM dimming, and operate within overlapping supply voltage ranges (8V-26V for MP4013GS vs. 4.5V-36V for RT8475GS). MP4013GS carries active product status and automotive grade qualification, making it suitable for production continuity.

For Enhanced Capability and Active Support:

LT8391AEFE#PBF offers superior specifications including automotive qualification, extended supply voltage range (4V-60V), and higher frequency operation (600kHz-2MHz). The 28-TSSOP-EP package provides thermal management advantages through an exposed pad. This part is recommended for new designs requiring the RT8475GS functionality.

MAX16831ATJ+ provides automotive-qualified operation with the widest supply voltage range (5.5V-76V) and integrated thermal management in a 32-TQFN package. This device is suitable for applications requiring high voltage input capability and enhanced reliability.

For Cost-Optimized Solutions:

AT9933LG-G offers automotive AEC-Q100 qualification in a compact 8-SOIC package with PWM dimming support. The narrower pin count reduces board space requirements, though supply voltage specification lacks a minimum value in provided data.

For Narrow Input Voltage Applications:

HVLED002TR operates within a constrained 7V-25V supply range with 250kHz switching frequency. This part is suitable only for applications where input voltage naturally falls within this window.

All substitute parts maintain ROHS3 compliance and operate across the -40°C to 125°C temperature range specified for the RT8475GS.

Frequently Asked Questions (FAQ)

Q: Can I directly replace RT8475GS with MP4013GS without PCB modifications?

A: MP4013GS shares the same 16-SOIC package footprint as RT8475GS, enabling direct pin-compatible replacement. However, verify that the 8V minimum supply voltage requirement of MP4013GS aligns with your application's input voltage specification. The RT8475GS operates down to 4.5V, so applications with lower input voltages require alternative substitutes.

Q: What is the key difference between LT3755IMSE-1#PBF and LT3796EFE-1#PBF?

A: Both are Analog Devices LED driver controllers with analog and PWM dimming support. LT3755IMSE-1#PBF operates in the 4.5V-40V range with 100kHz-1MHz frequency in a 16-MSOP-EP package. LT3796EFE-1#PBF extends to 6V-100V supply range in a larger 28-TSSOP-EP package. Select LT3755IMSE-1#PBF for space-constrained designs; choose LT3796EFE-1#PBF for high-voltage applications.

Q: Why does HVLED002TR have a narrower supply voltage range than RT8475GS?

A: HVLED002TR is specified for 7V-25V operation, which is narrower than RT8475GS (4.5V-36V). This part is suitable only for applications where input voltage naturally remains within the 7V-25V window. For applications requiring the full 4.5V-36V range, select LT8391AEFE#PBF, LT3755IMSE-1#PBF, or MAX16831ATJ+.

Q: Are all substitute parts automotive qualified?

A: Automotive qualification varies. AT9933LG-G, LT8391AEFE#PBF, and MAX16831ATJ+ carry automotive grades (AEC-Q100 or automotive designation). LT3755IMSE-1#PBF, LT3796EFE-1#PBF, and HVLED002TR do not list automotive qualification in provided specifications. For automotive applications, prioritize AT9933LG-G, LT8391AEFE#PBF, or MAX16831ATJ+.

Q: What packaging options are available for RT8475GS substitutes?

A: Substitute parts span multiple surface-mount packages: 8-SOIC (AT9933LG-G, HVLED002TR), 14-SOIC (RT8475GS original), 16-SOIC (MP4013GS), 16-MSOP-EP (LT3755IMSE-1#PBF), 28-TSSOP-EP (LT3796EFE-1#PBF, LT8391AEFE#PBF), and 32-TQFN (MAX16831ATJ+). Verify PCB layout compatibility before selecting a substitute with different pin count or package dimensions.

Q: Does the RT8475GS "Not For New Designs" status affect substitute selection?

A: Yes. The "Not For New Designs" status indicates the RT8475GS is in end-of-life phase. All recommended substitutes carry "Active" product status, ensuring long-term availability and manufacturer support. For new designs, select from active-status substitutes: MP4013GS, LT3755IMSE-1#PBF, LT3796EFE-1#PBF, LT8391AEFE#PBF, MAX16831ATJ+, or AT9933LG-G.

Q: Can I use LT8391AEFE#PBF in applications requiring the full 4.5V minimum input voltage?

A: LT8391AEFE#PBF operates down to 4V minimum supply voltage, which is compatible with the 4.5V minimum of RT8475GS. This part is suitable for applications requiring low-voltage input operation.