LM3430SD LED Driver Controller - Equivalent & Substitute Parts

Part Overview

The LM3430SD is a PWM-controlled LED driver IC manufactured by Texas Instruments, designed for single-output DC-DC controller applications in backlight systems. It operates as a SEPIC/Step-Up (Boost) topology controller with a 2MHz switching frequency and supports PWM dimming. The part is currently discontinued at DiGi Electronics, making equivalent substitutes necessary for new designs and production continuity. With 18,200 units in stock, existing inventory remains available, but long-term sourcing requires identification of compatible alternatives that maintain functional equivalence within the specified electrical and mechanical parameters.

Substiute Parts

LM3430SD

Texas InstrumentsIn Stock: 18226LM3430SD Datasheet

Current PartRFQ

HV9910CLG-G

Microchip TechnologyIn Stock: 17459HV9910CLG-G Datasheet

MFR RecommendedRFQ

LT3755EUD#TRPBF

Analog Devices Inc.In Stock: 3921LT3755EUD#TRPBF Datasheet

MFR RecommendedRFQ

LT3791MPFE#PBF

Analog Devices Inc.In Stock: 883LT3791MPFE#PBF Datasheet

MFR RecommendedRFQ

LT3796EFE#PBF

Analog Devices Inc.In Stock: 2963LT3796EFE#PBF Datasheet

MFR RecommendedRFQ

LT8391AIFE#PBF

Analog Devices Inc.In Stock: 1020LT8391AIFE#PBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM3430SD is determined by the following critical parameters:

Functional Requirements:

• Single output DC-DC controller topology
• PWM dimming capability
• Operating voltage range compatibility (minimum 6V supply)
• Switching frequency suitable for LED driver applications (100kHz to 2MHz range)

Electrical Compatibility:

• Supply voltage range must encompass or overlap with 6V to 40V
• Operating temperature range must support -40°C to 125°C minimum
• Topology must support SEPIC, Step-Up (Boost), or multi-topology configurations that include boost capability

Mechanical Compatibility:

• Surface mount package with exposed pad design
• Pin count and footprint compatibility for board-level integration

The five identified substitutes meet these criteria with varying topology support and voltage specifications. All substitutes are active products with RoHS3 compliance, addressing the discontinued status of the original part.

Parameter Comparison

Engineering Selection Recommendations

LT3755EUD#TRPBF provides the closest functional match to the LM3430SD. It supports SEPIC and Step-Up (Boost) topologies within the 4.5V to 40V supply range, matching the original part's voltage envelope. The 100kHz to 1MHz frequency range encompasses the 2MHz operation point. This part is active, RoHS3 compliant, and available in 16-QFN (3x3) package with exposed pad, suitable for surface mount applications. Operating temperature range of 0°C to 125°C covers the critical lower bound of the original specification.

LT3796EFE#PBF offers identical supply voltage range (6V to 100V) and operating temperature (-40°C to 125°C) to the LM3430SD, with SEPIC topology support. The 100kHz to 1MHz frequency range and 28-TSSOP-EP package provide alternative form factor with higher pin count. This part is active and RoHS3 compliant.

LT8391AIFE#PBF extends the supply range to 4V to 60V and supports Step-Up (Boost) topology with 600kHz to 2MHz frequency range, matching the original 2MHz operation. It includes automotive-grade qualification and is available in 28-TSSOP-EP package. Operating temperature range of -40°C to 125°C matches the original specification exactly.

LT3791MPFE#PBF supports Step-Up (Boost) topology with extended operating temperature (-55°C to 150°C) and 200kHz to 700kHz frequency range. Supply voltage range of 4.7V to 60V encompasses the original 6V to 40V specification. The 38-TSSOP-EP package provides the largest pin count among substitutes.

HV9910CLG-G from Microchip Technology operates as a Step-Down (Buck) controller with 15V to 450V supply range. This topology differs from the original SEPIC/Boost configuration and is suitable only for applications where buck conversion is acceptable. The 8-SOIC package is the smallest form factor available.

All substitute parts are active products with RoHS3 compliance, addressing regulatory and supply chain continuity concerns associated with the discontinued LM3430SD.

Frequently Asked Questions (FAQ)

Q: Can the HV9910CLG-G directly replace the LM3430SD?

A: No. The HV9910CLG-G implements Step-Down (Buck) topology, while the LM3430SD uses SEPIC/Step-Up (Boost) topology. These topologies serve different voltage conversion requirements. The HV9910CLG-G is suitable only if your application requires buck conversion and operates within its 15V to 450V supply range.

Q: Which substitute has the closest electrical compatibility?

A: The LT3755EUD#TRPBF provides the closest match. It supports SEPIC and Step-Up (Boost) topologies, operates within 4.5V to 40V supply range (encompassing the original 6V to 40V), and maintains PWM dimming capability with 100kHz to 1MHz frequency range.

Q: Are all substitutes RoHS compliant?

A: The LM3430SD is RoHS non-compliant. All five substitute parts are RoHS3 compliant, meeting current regulatory requirements for new designs and production.

Q: What are the package differences, and do they affect board design?

A: The LM3430SD uses 12-WSON (3x3) package. Substitutes vary: HV9910CLG-G (8-SOIC), LT3755EUD#TRPBF (16-QFN 3x3), LT3791MPFE#PBF (38-TSSOP-EP), LT3796EFE#PBF (28-TSSOP-EP), and LT8391AIFE#PBF (28-TSSOP-EP). Different packages require PCB layout redesign, including trace routing, thermal management, and decoupling capacitor placement.

Q: Can I use a substitute with a higher maximum supply voltage?

A: Yes, provided the substitute's minimum supply voltage does not exceed your application's operating point. For example, LT3796EFE#PBF supports 6V to 100V, which is compatible with the original 6V to 40V requirement. Verify that the controller's internal voltage regulation and protection circuits are suitable for your specific supply voltage.

Q: What is the significance of the operating temperature range differences?

A: The LM3430SD specifies -40°C to 125°C. LT3755EUD#TRPBF operates 0°C to 125°C, which does not cover the full lower temperature range. LT3791MPFE#PBF extends to -55°C to 150°C, providing wider margin. Verify your application's thermal requirements before selecting a substitute with a narrower temperature range.

Q: Are the frequency specifications interchangeable?

A: Switching frequency affects component selection (inductors, capacitors) and EMI characteristics. The LM3430SD operates at 2MHz. LT8391AIFE#PBF supports 600kHz to 2MHz, matching this specification. Other substitutes operate at lower frequencies (100kHz to 1MHz range), which may require different passive component values and filtering strategies.

Q: Do all substitutes support PWM dimming?

A: Yes. All five substitutes support PWM dimming. HV9910CLG-G, LT3755EUD#TRPBF, LT3791MPFE#PBF, LT3796EFE#PBF, and LT8391AIFE#PBF all include PWM dimming capability, with some also supporting analog dimming control.