LM27951SDX LED Driver IC Equivalent & Substitute Parts

Part Overview

The LM27951SDX is a 4-output LED driver IC manufactured by Texas Instruments, designed for backlight applications using switched-capacitor (charge pump) topology with PWM dimming capability. The main part number LM27951SDX is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. Active alternatives with identical or compatible electrical and mechanical specifications are available from Texas Instruments and other manufacturers.

Substiute Parts

LM27951SDX

Texas InstrumentsIn Stock: 4626LM27951SDX Datasheet

Current PartRFQ

LM27951SDX/NOPB

Texas InstrumentsIn Stock: 3296LM27951SDX/NOPB Datasheet

DirectRFQ

LM27951SD/NOPB

Texas InstrumentsIn Stock: 6268LM27951SD/NOPB Datasheet

Parametric EquivalentRFQ

LM27952SD/NOPB

National SemiconductorIn Stock: 8348LM27952SD/NOPB Datasheet

Parametric EquivalentRFQ

LM27952SDX/NOPB

Texas InstrumentsIn Stock: 1511LM27952SDX/NOPB Datasheet

Parametric EquivalentRFQ

ISL97692IRTZ

Renesas Electronics CorporationIn Stock: 6182ISL97692IRTZ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM27951SDX is determined by the following critical parameters: topology (switched-capacitor charge pump), number of outputs (4), output voltage range (2.5V to 3.9V), current per channel (30mA), switching frequency (750kHz), PWM dimming capability, package type (14-WSON 4x3), and operating temperature range (-40°C to 85°C).

Substitute parts are grouped into two categories:

Direct Equivalents (Texas Instruments LM27951 Series): Parts LM27951SDX/NOPB and LM27951SD/NOPB maintain identical electrical specifications and package configuration. These parts differ only in product status (active vs. obsolete) and RoHS compliance level.

Parametric Equivalents (LM27952 Series): Parts LM27952SDX/NOPB and LM27952SD/NOPB share the same topology, output count, frequency, dimming method, and package but feature a minimum supply voltage of 3V instead of 2.8V. These are functionally compatible in applications where the supply voltage remains at or above 3V.

Alternative Topology (Renesas ISL97692IRTZ): This part uses step-up (boost) topology instead of charge pump, with higher output current (40mA per channel) and higher output voltage (26V). It is listed as manufacturer-recommended but represents a different circuit topology and requires application-level validation.

Parameter Comparison

Engineering Selection Recommendations

For applications currently using the obsolete LM27951SDX, the recommended substitution path is LM27951SDX/NOPB or LM27951SD/NOPB. Both parts maintain identical electrical and mechanical specifications while offering active product status and ROHS3 compliance, eliminating the need for circuit redesign or PCB layout modification.

The LM27952SDX/NOPB and LM27952SD/NOPB variants are suitable substitutes only when the application supply voltage is guaranteed to remain at 3V or above. The minimum supply voltage specification of 3V (versus 2.8V for LM27951 variants) represents the only electrical difference in this group.

The ISL97692IRTZ from Renesas Electronics represents a different circuit topology (step-up boost converter) with higher output voltage capability (26V) and higher per-channel current (40mA). This part is not a direct substitute and requires full application circuit redesign and validation. Selection of this part should be based on specific application requirements that cannot be met by the LM27951 or LM27952 families.

All recommended substitutes maintain ROHS3 compliance and REACH unaffected status, supporting modern procurement and environmental requirements.

Frequently Asked Questions (FAQ)

Q: Can LM27951SDX/NOPB be used as a direct replacement for LM27951SDX?

A: Yes. LM27951SDX/NOPB is a direct equivalent with identical electrical specifications, package configuration, and pin assignment. The primary differences are product status (active vs. obsolete) and RoHS compliance certification. No circuit or layout changes are required.

Q: What is the key difference between LM27951 and LM27952 variants?

A: The minimum supply voltage specification differs. LM27951 variants support 2.8V minimum input, while LM27952 variants require 3V minimum. All other electrical parameters, topology, output count, frequency, and package remain identical. Selection depends on the application's minimum supply voltage requirement.

Q: Can ISL97692IRTZ replace LM27951SDX in existing designs?

A: No. ISL97692IRTZ uses step-up (boost) topology instead of switched-capacitor charge pump, produces 26V output instead of 2.5V to 3.9V, and uses a different package (16-TQFN vs. 14-WSON). Full circuit redesign and application validation are required.

Q: What is the significance of the /NOPB suffix in part numbers?

A: The /NOPB suffix indicates lead-free (no-lead) and RoHS-compliant packaging. Parts with this suffix meet modern environmental and regulatory requirements. Parts without this suffix may contain lead and may not meet current RoHS standards.

Q: Are there any moisture sensitivity differences between substitute parts?

A: LM27951SDX, LM27951SDX/NOPB, LM27951SD/NOPB, LM27952SDX/NOPB, and LM27952SD/NOPB all carry MSL rating 1 (unlimited moisture sensitivity level), indicating no special moisture handling requirements. ISL97692IRTZ carries MSL rating 3 (168 hours), requiring controlled storage and handling conditions.

Q: Which substitute part offers the best inventory availability?

A: LM27952SD/NOPB shows the highest inventory level at 8,318 pieces. LM27951SD/NOPB offers 6,200 pieces. Both are suitable for high-volume procurement. Specific availability should be confirmed with the component supplier.