LP8557IAYFQR LED Driver IC Equivalent & Substitute Parts

Part Overview

The LP8557IAYFQR is a Texas Instruments LED Driver IC featuring 6 output channels with integrated DC-DC Step-Up (Boost) topology and PWM dimming capability. This Active status component operates across a 2.7V to 5.5V supply range, delivering 28V output at 25mA per channel in a compact 16-DSBGA package. The device is designed for backlight applications requiring regulated multi-channel LED drive capability.

Equivalent and substitute parts are identified to address supply availability, packaging preferences, performance requirements, or design optimization needs while maintaining functional compatibility within specified electrical and mechanical parameters.

Substiute Parts

LP8557IAYFQR

Texas InstrumentsIn Stock: 26155LP8557IAYFQR Datasheet

Current PartRFQ

LP8557AYFQR

Texas InstrumentsIn Stock: 16399LP8557AYFQR Datasheet

Parametric EquivalentRFQ

LP8557AYFQT

Texas InstrumentsIn Stock: 1671LP8557AYFQT Datasheet

Parametric EquivalentRFQ

LP8557IAYFQT

Texas InstrumentsIn Stock: 1587LP8557IAYFQT Datasheet

Parametric EquivalentRFQ

BD9470AEFV-E2

Rohm SemiconductorIn Stock: 938BD9470AEFV-E2 Datasheet

MFR RecommendedRFQ

FAN5701UMP15X

Fairchild SemiconductorIn Stock: 8648FAN5701UMP15X Datasheet

MFR RecommendedRFQ

LT3598EFE#TRPBF

Analog Devices Inc.In Stock: 16550LT3598EFE#TRPBF Datasheet

MFR RecommendedRFQ

LT3598IFE#PBF

Analog Devices Inc.In Stock: 1962LT3598IFE#PBF Datasheet

MFR RecommendedRFQ

MP3387LGRT-Z

Monolithic Power Systems Inc.In Stock: 8246MP3387LGRT-Z Datasheet

MFR RecommendedRFQ

RT8532GQW

Richtek USA Inc.In Stock: 26054RT8532GQW Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts are classified into two categories based on substitution criteria:

Parametric Equivalents (Direct Substitutes): Parts LP8557AYFQR, LP8557AYFQT, and LP8557IAYFQT share identical electrical specifications, topology, output configuration, and package type with the main part. These differ only in temperature grade or packaging format (Tape & Reel vs. alternative reels) and are interchangeable within the same design without circuit modification.

Manufacturer Recommended Alternatives: Parts from Rohm Semiconductor (BD9470AEFV-E2), Fairchild Semiconductor (FAN5701UMP15X), Analog Devices (LT3598EFE#TRPBF, LT3598IFE#PBF), Monolithic Power Systems (MP3387LGRT-Z), and Richtek (RT8532GQW) are functionally equivalent but operate under different electrical constraints. Substitution requires design verification based on the following key parameters:

• Supply voltage range compatibility
• Output voltage capability
• Current delivery per channel
• Switching frequency
• Package footprint and thermal characteristics
• Operating temperature range
• Dimming control method (PWM, Analog, or combined)

Parameter Comparison

Engineering Selection Recommendations

Direct Substitution (No Design Changes Required): LP8557AYFQR, LP8557AYFQT, and LP8557IAYFQT are functionally identical to the LP8557IAYFQR. All are Active status, ROHS3 compliant, and carry MSL 1 rating. Selection among these three is based on packaging format (Tape & Reel variants) and current inventory availability.

Cross-Manufacturer Substitution (Design Verification Required):

BD9470AEFV-E2 (Rohm Semiconductor) operates at higher supply voltages (9V-35V minimum) and delivers 250mA per channel, making it unsuitable for 2.7V-5.5V input designs without external voltage regulation. MSL rating is 3 (168 Hours), requiring controlled storage conditions.

FAN5701UMP15X (Fairchild Semiconductor) uses Switched Capacitor topology instead of Step-Up Boost, limiting output voltage capability and current delivery to 15mA per channel. Supply range matches (2.7V-5.5V), but reduced current capacity restricts application scope. MSL 1 rating and extended temperature range (-40°C to 85°C) provide advantages for harsh environments.

LT3598EFE#TRPBF and LT3598IFE#PBF (Analog Devices) support wider supply ranges (3V-30V) and higher output voltage (44V) with 30mA per channel. Extended operating temperature to 125°C (junction) and dual dimming control (Analog + PWM) offer design flexibility. Packaging differs (24-TSSOP vs. 16-DSBGA), requiring PCB layout modification. Both are Active status and ROHS3 compliant with MSL 1 rating.

MP3387LGRT-Z (Monolithic Power Systems) delivers 45mA per channel with Analog and PWM dimming in 24-TQFN package. Supply range (3V-25V) overlaps partially with the main part. Extended temperature range (-40°C to 125°C) and higher current capability support demanding applications. MSL 1 rating and ROHS3 compliance confirmed.

RT8532GQW (Richtek) provides 50mA per channel with 43V output capability across 2.5V-24V supply range. Frequency range (400kHz-1.2MHz) overlaps with the main part. 20-WQFN package (3x3) differs from 16-DSBGA, requiring layout redesign. MSL 3 rating (168 Hours) requires moisture control. ROHS3 compliant and Active status.

Frequently Asked Questions (FAQ)

Q: Can LP8557AYFQR replace LP8557IAYFQR directly without circuit changes? A: Yes. Both parts are parametrically identical with matching supply voltage (2.7V-5.5V), output voltage (28V), current per channel (25mA), topology (Step-Up Boost), and package (16-DSBGA). Differences are limited to packaging format (Tape & Reel variants). No design modification is required.

Q: What is the key difference between the Texas Instruments LP8557 series and the Analog Devices LT3598 series? A: The LP8557 operates at lower supply voltages (2.7V-5.5V) with fixed 28V output and PWM-only dimming. The LT3598 accepts wider supply ranges (3V-30V), delivers higher output voltage (44V), supports both Analog and PWM dimming, and operates at higher junction temperatures (up to 125°C). Package footprints differ (16-DSBGA vs. 24-TSSOP), requiring PCB redesign.

Q: Is the Fairchild FAN5701UMP15X suitable as a drop-in replacement? A: No. While the FAN5701 matches the supply voltage range (2.7V-5.5V) and package size category (16-pin), it uses Switched Capacitor topology instead of Step-Up Boost, limiting output voltage and current delivery to 15mA per channel. This reduced current capacity makes it unsuitable for applications requiring 25mA per channel.

Q: What are the packaging implications of switching from LP8557IAYFQR to RT8532GQW? A: The LP8557IAYFQR uses 16-DSBGA (0.5mm pitch), while the RT8532GQW uses 20-WQFN (3x3mm, 0.5mm pitch). Although both are fine-pitch packages, the footprint geometry differs significantly, requiring complete PCB layout redesign. Via placement, trace routing, and thermal management strategies must be re-evaluated.

Q: Does the Rohm BD9470AEFV-E2 work with 2.7V-5.5V supply designs? A: No. The BD9470AEFV-E2 requires a minimum supply voltage of 9V, making it incompatible with designs operating at 2.7V-5.5V without external step-up regulation. This part is intended for higher-voltage backlight applications.

Q: What is the significance of MSL rating differences between parts? A: MSL 1 (Unlimited) parts like LP8557IAYFQR, LT3598EFE#TRPBF, and MP3387LGRT-Z have no moisture sensitivity restrictions and can be stored indefinitely at room temperature. MSL 3 parts like BD9470AEFV-E2 and RT8532GQW require controlled storage (168 hours maximum at 30°C/60% RH before baking), adding supply chain complexity.

Q: Can I use RT8532GQW if my design requires 50mA per channel instead of 25mA? A: Yes, if your circuit topology and thermal design accommodate the higher current. The RT8532GQW delivers 50mA per channel with 43V output across a 2.5V-24V supply range. However, PCB layout must be redesigned for the 20-WQFN package, and thermal management must account for increased power dissipation. Verify that your supply voltage remains within the 2.5V-24V range.

Q: Are all substitute parts ROHS3 compliant? A: Yes. All parts listed—LP8557 variants, BD9470AEFV-E2, FAN5701UMP15X, LT3598 variants, MP3387LGRT-Z, and RT8532GQW—are confirmed ROHS3 compliant and REACH unaffected.