RT8476AGSP LED Driver IC Equivalent & Substitute Parts

Part Overview

The RT8476AGSP is an LED Driver IC manufactured by Richtek USA Inc., designed for power management applications in lighting and signage systems. This device functions as a DC-DC regulator with both step-down (buck) and step-up (boost) topology, featuring analog and PWM dimming capabilities. The part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The RT8476AGSP operates across a 4.5V to 40V supply range and is housed in an 8-SOP-EP package with automotive-grade qualification.

Key Parameters

Parameter	RT8476AGSP
Manufacturer	Richtek USA Inc.
Product Status	Obsolete
Type	DC DC Regulator
Topology	Step-Down (Buck), Step-Up (Boost)
Number of Outputs	1
Voltage - Supply (Min)	4.5V
Voltage - Supply (Max)	40V
Dimming	Analog, PWM
Applications	Lighting, Signage
Operating Temperature	-40°C ~ 85°C (TA)
Grade	Automotive
Package / Case	8-SOIC (0.154", 3.90mm Width) Exposed Pad
RoHS Status	ROHS3 Compliant
MSL	3 (168 Hours)

Substitute Part Grouping Explanation

Substitution for the RT8476AGSP is determined by the following critical parameters:

Topology: Step-Down (Buck), Step-Up (Boost) capability
Dimming Control: Analog and/or PWM dimming support
Supply Voltage Range: Minimum 4.5V to maximum 40V or higher
Number of Outputs: Single output configuration
Package Compatibility: Surface mount packages suitable for LED driver applications
Product Status: Active parts preferred for long-term availability
Compliance: ROHS3 compliance and automotive qualification where applicable

Substitute parts are grouped into two categories based on topology and dimming capability alignment with the RT8476AGSP specifications.

Parameter Comparison

Parameter	RT8476AGSP	LM3414MRX/NOPB	LT3478EFE-1#TRPBF	LT3478IFE-1#TRPBF	LT3517EFE#PBF	LT3517IFE#PBF	LT3517IUF#TRPBF	MP4601ES-LF	MP46885DN-LF	MPQ2483ADS-AEC1-LF
Type	DC DC Regulator	DC DC Regulator	DC DC Regulator	DC DC Regulator	DC DC Regulator	DC DC Regulator	DC DC Regulator	DC DC Regulator	DC DC Regulator	DC DC Regulator
Topology	Buck, Boost	Buck	Buck, Boost	Buck, Boost	Buck, Boost	Buck, Boost	Buck, Boost	Buck, Boost	Buck	Buck, Boost
Number of Outputs	1	1	1	1	1	1	1	1	1	1
Voltage - Supply (Min)	4.5V	4.5V	2.8V	2.8V	3V	3V	3V	4.5V	4.5V	4.5V
Voltage - Supply (Max)	40V	42V	36V	36V	30V	30V	30V	75V	80V	55V
Dimming	Analog, PWM	Analog, PWM	PWM	PWM	Analog, PWM	Analog, PWM	Analog, PWM	Analog, PWM	PWM	Analog, PWM
Operating Temperature	-40°C ~ 85°C (TA)	-40°C ~ 125°C (TJ)	-40°C ~ 125°C (TJ)	-40°C ~ 125°C (TJ)	-40°C ~ 125°C (TJ)	-40°C ~ 125°C (TJ)	-40°C ~ 125°C (TJ)	-20°C ~ 85°C (TA)	-40°C ~ 85°C (TA)	-40°C ~ 125°C (TJ)
Grade	Automotive	Automotive	-	-	-	-	-	-	Automotive	Automotive
Product Status	Obsolete	Active	Active	Active	Active	Active	Active	Active	Active	Active
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant

Engineering Selection Recommendations

Primary Substitutes (Full Topology & Dimming Match)

LT3517EFE#PBF, LT3517IFE#PBF, and LT3517IUF#TRPBF from Analog Devices Inc. provide the closest functional alignment with the RT8476AGSP. These parts maintain buck-boost topology with analog and PWM dimming support. All three are active products with ROHS3 compliance. The LT3517 series operates across 3V to 30V, which covers the RT8476AGSP's 4.5V to 40V range within the lower portion. The LT3517IUF#TRPBF offers a 16-QFN package alternative to the 8-SOP-EP.

LT3478EFE-1#TRPBF and LT3478IFE-1#TRPBF from Analog Devices Inc. support buck-boost topology with PWM dimming. These parts operate across 2.8V to 36V and are active products with ROHS3 compliance. The supply voltage maximum of 36V falls slightly below the RT8476AGSP's 40V specification.

Secondary Substitutes (Topology or Dimming Variation)

MP4601ES-LF from Monolithic Power Systems Inc. provides buck-boost topology with analog and PWM dimming across 4.5V to 75V, exceeding the RT8476AGSP's voltage range. This part is active with ROHS3 compliance and housed in a 16-SOIC package.

MPQ2483ADS-AEC1-LF from Monolithic Power Systems Inc. maintains buck-boost topology with analog and PWM dimming across 4.5V to 55V. This part carries automotive qualification (AEC-Q100) and ROHS3 compliance in a 14-SOIC package.

LM3414MRX/NOPB from Texas Instruments provides step-down (buck) topology only, limiting its application scope compared to the RT8476AGSP's dual topology. However, it maintains analog and PWM dimming support across 4.5V to 42V with automotive qualification and ROHS3 compliance.

MP46885DN-LF from Monolithic Power Systems Inc. offers step-down (buck) topology with PWM dimming only, across 4.5V to 80V. This part carries automotive qualification and ROHS3 compliance in an 8-SOICE package.

Availability & Compliance

All substitute parts listed are active products with ROHS3 compliance and unlimited or extended moisture sensitivity levels, ensuring long-term availability and manufacturing compatibility. Parts with automotive qualification (LM3414MRX/NOPB, MP46885DN-LF, MPQ2483ADS-AEC1-LF) are recommended for applications requiring automotive-grade components.

Frequently Asked Questions (FAQ)

Q: Can LT3517EFE#PBF directly replace RT8476AGSP in all applications?

A: LT3517EFE#PBF matches the RT8476AGSP in topology (buck-boost) and dimming capability (analog and PWM). However, the LT3517 operates to a maximum of 30V versus the RT8476AGSP's 40V. Direct substitution is valid only if your application's supply voltage does not exceed 30V. Package differences (16-TSSOP versus 8-SOP-EP) require PCB layout modification.

Q: What is the difference between LT3478 and LT3517 series?

A: Both series support buck-boost topology from Analog Devices Inc. The LT3478 series (LT3478EFE-1#TRPBF, LT3478IFE-1#TRPBF) provides PWM dimming only and operates to 36V maximum with 4.5A switch current. The LT3517 series (LT3517EFE#PBF, LT3517IFE#PBF, LT3517IUF#TRPBF) provides analog and PWM dimming and operates to 30V maximum with 1.5A switch current. Selection depends on dimming control requirements and current capacity needs.

Q: Why is LM3414MRX/NOPB listed as a substitute if it only supports buck topology?

A: LM3414MRX/NOPB is included because it was explicitly listed in the RT8476AGSP's substitute field in the source data. While it provides only step-down (buck) topology versus the RT8476AGSP's dual topology, it maintains analog and PWM dimming support, automotive qualification, and operates across 4.5V to 42V. This part is suitable for applications requiring buck-only regulation.

Q: Are all substitute parts automotive-qualified?

A: No. Automotive qualification is specified for LM3414MRX/NOPB, MP46885DN-LF, and MPQ2483ADS-AEC1-LF. The Analog Devices LT3517 and LT3478 series, and MP4601ES-LF do not carry automotive grade designation. For automotive applications, select from the qualified parts listed above.

Q: What package options are available among substitutes?

A: Substitute parts are available in multiple packages: 8-SOIC (LM3414MRX/NOPB, MP46885DN-LF), 14-SOIC (MPQ2483ADS-AEC1-LF), 16-SOIC (MP4601ES-LF), 16-TSSOP (LT3478EFE-1#TRPBF, LT3478IFE-1#TRPBF, LT3517EFE#PBF, LT3517IFE#PBF), and 16-QFN (LT3517IUF#TRPBF). The original RT8476AGSP uses 8-SOP-EP. Package selection affects PCB layout and thermal management considerations.

Q: Which substitute offers the widest supply voltage range?

A: MP46885DN-LF supports 4.5V to 80V, the widest range among substitutes. MP4601ES-LF supports 4.5V to 75V. Both exceed the RT8476AGSP's 40V maximum. These parts are suitable for applications requiring extended voltage headroom.

Q: Do all substitutes maintain ROHS3 compliance?

A: Yes. All substitute parts listed carry ROHS3 compliance status, matching the RT8476AGSP's environmental certification.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message