LM5035ASQ/NOPB Equivalent & Substitute Parts

Part Overview

The LM5035ASQ/NOPB is a half-bridge regulator controller IC manufactured by Texas Instruments, designed for positive output, isolation-capable step-up/step-down DC-DC applications. This device operates across a 13V to 105V supply voltage range with selectable switching frequencies of 200kHz or 500kHz. The part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity.

Substiute Parts

LM5035ASQ/NOPB

Texas InstrumentsIn Stock: 704LM5035ASQ/NOPB Datasheet

Current PartRFQ

LM5035BSQ/NOPB

Texas InstrumentsIn Stock: 1419LM5035BSQ/NOPB Datasheet

Parametric EquivalentRFQ

LM5035BSQX/NOPB

Texas InstrumentsIn Stock: 4075LM5035BSQX/NOPB Datasheet

Parametric EquivalentRFQ

LM5035CSQ/NOPB

Texas InstrumentsIn Stock: 2014LM5035CSQ/NOPB Datasheet

Parametric EquivalentRFQ

LM5035CSQX/NOPB

Texas InstrumentsIn Stock: 3181LM5035CSQX/NOPB Datasheet

Parametric EquivalentRFQ

LM5039SQX/NOPB

Texas InstrumentsIn Stock: 1014LM5039SQX/NOPB Datasheet

Parametric EquivalentRFQ

LTC3769EUF#TRPBF

Analog Devices Inc.In Stock: 18319LTC3769EUF#TRPBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM5035ASQ/NOPB is determined by strict parametric equivalence across the following critical criteria:

Primary Equivalence Parameters:

• Output Type: Transistor Driver
• Function: Step-Up/Step-Down
• Output Configuration: Positive, Isolation Capable
• Topology: Half-Bridge
• Number of Outputs: 1
• Output Phases: 1
• Voltage - Supply (Vcc/Vdd): 13V ~ 105V
• Frequency - Switching: 200kHz, 500kHz
• Synchronous Rectifier: Yes
• Clock Sync: Yes
• Control Features: Frequency Control, Ramp, Soft Start
• Operating Temperature: -40°C ~ 125°C (TJ)
• Package / Case: 24-WFQFN Exposed Pad
• Supplier Device Package: 24-WQFN (4x5)
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level (MSL): 1 (Unlimited)
• REACH Status: REACH Unaffected

Substitute Categories:

Category 1: Texas Instruments LM5035 Series (Parametric Equivalents) Parts LM5035BSQ/NOPB, LM5035BSQX/NOPB, LM5035CSQ/NOPB, and LM5035CSQX/NOPB meet all primary equivalence parameters. These variants differ only in product status and packaging designation (TR vs. standard), with no functional or electrical differences affecting circuit performance.

Category 2: Texas Instruments LM5039 Series (Parametric Equivalent) Part LM5039SQX/NOPB maintains identical electrical specifications and topology to the LM5035ASQ/NOPB, with the same supply voltage range, switching frequencies, and control features. The base product number differs, but parametric compatibility is complete.

Category 3: Analog Devices LTC3769EUF#TRPBF (Manufacturer Recommended Alternative) The LTC3769EUF#TRPBF is designated as a manufacturer-recommended alternative. While it shares the half-bridge topology, transistor driver output type, and identical package footprint (24-WFQFN), it operates across a different supply voltage range (4.5V ~ 60V) and supports Boost and SEPIC topologies in addition to step-up/step-down operation. This part is suitable for applications where the lower supply voltage range is acceptable and the extended topology support is beneficial.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Electrical and Functional Performance):

Select LM5035BSQX/NOPB or LM5035CSQX/NOPB as primary alternatives. Both parts are active products with full parametric equivalence to the LM5035ASQ/NOPB. LM5035BSQX/NOPB offers the highest inventory availability (4055 units) and active product status, making it the optimal choice for new designs and production continuity. LM5035CSQX/NOPB provides an additional active alternative with substantial inventory (3140 units).

For Last-Time-Buy Scenarios:

LM5035BSQ/NOPB and LM5035CSQ/NOPB are designated as Last Time Buy products. These parts maintain complete parametric equivalence but have limited remaining availability. Selection should be based on packaging requirements and inventory allocation.

For Extended Supply Voltage Range Applications:

LTC3769EUF#TRPBF is designated as a manufacturer-recommended alternative. This part operates across a lower supply voltage range (4.5V ~ 60V) compared to the LM5035ASQ/NOPB (13V ~ 105V). The LTC3769EUF#TRPBF supports additional topologies (Boost and SEPIC) and includes enhanced control features (Current Limit, Enable, Power Good). Selection of this part requires circuit redesign validation and is appropriate only when the lower supply voltage range and extended topology support align with application requirements. The LTC3769EUF#TRPBF does not support Clock Sync functionality.

Compliance and Regulatory Considerations:

All substitute parts maintain ROHS3 compliance, MSL 1 (Unlimited) moisture sensitivity rating, and REACH Unaffected status, ensuring regulatory alignment with the original LM5035ASQ/NOPB.

Frequently Asked Questions (FAQ)

Q: Can LM5035BSQX/NOPB be used as a direct drop-in replacement for LM5035ASQ/NOPB?

A: Yes. LM5035BSQX/NOPB is parametrically equivalent across all electrical specifications, control features, and package footprint. The 24-WQFN (4x5) package dimensions and pinout are identical, enabling direct PCB substitution without circuit modification.

Q: What is the difference between LM5035BSQ/NOPB and LM5035BSQX/NOPB?

A: Both parts are parametrically identical. The primary difference is product status: LM5035BSQ/NOPB is Last Time Buy, while LM5035BSQX/NOPB is Active. The "X" designation in LM5035BSQX/NOPB indicates extended availability. For new designs, LM5035BSQX/NOPB is recommended due to active product status and higher inventory levels.

Q: Why is LTC3769EUF#TRPBF listed as a manufacturer-recommended alternative if it has different electrical specifications?

A: LTC3769EUF#TRPBF is designated as a manufacturer-recommended alternative because it addresses the obsolescence of the LM5035ASQ/NOPB while maintaining the same package footprint and core half-bridge topology. However, the reduced supply voltage range (4.5V ~ 60V vs. 13V ~ 105V) and absence of Clock Sync require application-level validation. This part is suitable for designs where the lower supply voltage range is acceptable and the extended topology support (Boost, SEPIC) provides additional functionality.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All substitute parts listed—LM5035BSQ/NOPB, LM5035BSQX/NOPB, LM5035CSQ/NOPB, LM5035CSQX/NOPB, LM5039SQX/NOPB, and LTC3769EUF#TRPBF—are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity and REACH Unaffected status.

Q: What is the package footprint difference between 24-WQFN (4x5) and 24-QFN (4x4)?

A: The 24-WQFN (4x5) package used by the LM5035 series measures 4mm × 5mm, while the 24-QFN (4x4) package used by the LTC3769EUF#TRPBF measures 4mm × 4mm. Although both are 24-pin QFN packages with exposed pads, the dimensional difference requires PCB layout modification if substituting with the LTC3769EUF#TRPBF.

Q: Can LM5039SQX/NOPB be used interchangeably with LM5035 variants?

A: Yes. LM5039SQX/NOPB maintains identical electrical specifications, control features, and package footprint as the LM5035 series. The base product number differs, but parametric compatibility is complete, enabling direct substitution without circuit modification.

Q: What inventory considerations should guide part selection?

A: LM5035BSQX/NOPB offers the highest inventory availability (4055 units) among active products, followed by LM5035CSQX/NOPB (3140 units). For applications requiring immediate availability, LTC3769EUF#TRPBF has the largest inventory (18248 units). Last Time Buy products (LM5035BSQ/NOPB and LM5035CSQ/NOPB) have limited remaining stock and should be selected only when specific packaging or qualification requirements mandate their use.