LM2575-12BU TR Buck Switching Regulator Equivalent & Substitute Parts

Part Overview

The LM2575-12BU TR is a buck switching regulator IC manufactured by Microchip Technology, designed for step-down voltage conversion with a fixed 12V output and 1A current capacity. This part operates across an input voltage range of 4V to 40V with a switching frequency of 52kHz and is housed in a TO-263-6 D2PAK package with 5 leads plus tab.

The LM2575-12BU TR is classified as obsolete. Identifying equivalent and substitute parts is necessary to ensure design continuity, maintain supply chain reliability, and access components with active product status and improved compliance certifications.

Substiute Parts

LM2575-12BU TR

Microchip TechnologyIn Stock: 943LM2575-12BU TR Datasheet

Current PartRFQ

LM2575-12WU-TR

Microchip TechnologyIn Stock: 1522LM2575-12WU-TR Datasheet

DirectRFQ

LM2596S-12/NOPB

Texas InstrumentsIn Stock: 2014LM2596S-12/NOPB Datasheet

MFR RecommendedRFQ

LM2596SX-12/NOPB

Texas InstrumentsIn Stock: 35465LM2596SX-12/NOPB Datasheet

MFR RecommendedRFQ

NCV2575D2T-12R4G

onsemiIn Stock: 5844NCV2575D2T-12R4G Datasheet

MFR RecommendedRFQ

TL2575-12IKTTR

Texas InstrumentsIn Stock: 3027TL2575-12IKTTR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM2575-12BU TR is determined by the following critical parameters:

• Output Voltage: Must be fixed at 12V
• Package / Case: Must be TO-263-6, D2PAK (5 Leads + Tab)
• Mounting Type: Must be Surface Mount
• Output Configuration: Must be Positive
• Topology: Must be Buck
• Number of Outputs: Must be 1
• Operating Temperature Range: Must support -40°C to 125°C (TJ)

Substitute parts are grouped into two categories based on output current capacity:

Category 1: Direct Current Rating Match (1A Output) Parts with 1A output current maintain identical electrical performance characteristics and can serve as direct replacements in applications designed for the original 1A specification.

Category 2: Higher Current Rating (3A Output) Parts with 3A output current provide increased current capacity while maintaining all other critical parameters. These parts are suitable for applications where the original 1A rating is sufficient but higher current headroom is desired.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: LM2575-12WU-TR

The LM2575-12WU-TR is the direct equivalent to the LM2575-12BU TR. Both parts share identical electrical specifications, output current rating (1A), switching frequency (52kHz), and package configuration. The LM2575-12WU-TR holds active product status and meets ROHS3 compliance, addressing the obsolescence and compliance limitations of the original part. This part is the preferred choice for direct replacement in existing designs.

Secondary Recommendation: TL2575-12IKTTR

The TL2575-12IKTTR, manufactured by Texas Instruments, maintains the same 1A output current, 52kHz switching frequency, and TO-263-6 D2PAK package as the original part. It is actively produced and ROHS3 compliant. The minimum input voltage specification is 4.75V compared to 4V for the original part; this difference is acceptable in most applications where the input voltage floor exceeds 4.75V.

Alternative Recommendation: LM2596S-12/NOPB or LM2596SX-12/NOPB

The LM2596S-12/NOPB and LM2596SX-12/NOPB are higher-current alternatives (3A output) suitable for applications requiring increased current capacity. Both parts maintain the 12V fixed output, TO-263-6 D2PAK package, and -40°C to 125°C operating temperature range. The switching frequency increases to 150kHz, which may reduce output filter component sizes. These parts are actively produced and ROHS3 compliant. Selection of these parts is appropriate when design margins or future current requirements justify the higher rating.

Not Recommended: NCV2575D2T-12R4G

While the NCV2575D2T-12R4G matches the 1A output current and 52kHz switching frequency, it carries obsolete product status. Additionally, the minimum input voltage specification is 4.75V. This part should not be selected as a replacement for the LM2575-12BU TR.

Frequently Asked Questions (FAQ)

Q: Can the LM2575-12WU-TR be used as a direct replacement for the LM2575-12BU TR?

A: Yes. The LM2575-12WU-TR is electrically and mechanically identical to the LM2575-12BU TR. Both parts deliver 12V at 1A output, operate at 52kHz switching frequency, and use the TO-263-6 D2PAK package. The LM2575-12WU-TR is actively produced and ROHS3 compliant, making it the preferred replacement.

Q: What is the difference between the 1A and 3A output current variants?

A: The 1A variants (LM2575-12BU TR, LM2575-12WU-TR, TL2575-12IKTTR, NCV2575D2T-12R4G) are designed for applications requiring up to 1A output current. The 3A variants (LM2596S-12/NOPB, LM2596SX-12/NOPB) provide three times the current capacity. Selection depends on the actual load current requirement. If the application draws less than 1A, either variant is suitable; if higher current is needed, the 3A parts are appropriate.

Q: Does the switching frequency difference between 52kHz and 150kHz affect circuit design?

A: Yes. The LM2596 series operates at 150kHz compared to 52kHz for the LM2575 series. Higher switching frequency allows for smaller output filter inductors and capacitors, reducing board space and component cost. However, designs optimized for 52kHz operation may require recalculation of filter component values if switching to the 150kHz variant. The higher frequency may also increase switching losses in certain applications.

Q: Are all substitute parts available in the same packaging options?

A: All substitute parts listed use the TO-263-6 D2PAK (5 Leads + Tab) package for surface mount applications. However, packaging options (Tape & Reel, Cut Tape, Tube) differ by manufacturer and part number. Verify packaging availability with your supplier based on procurement requirements.

Q: What is the significance of RoHS compliance for this part?

A: The original LM2575-12BU TR is RoHS non-compliant. All recommended substitutes (LM2575-12WU-TR, TL2575-12IKTTR, LM2596S-12/NOPB, LM2596SX-12/NOPB) are ROHS3 compliant. ROHS3 compliance is required for products sold into markets with RoHS regulations and is increasingly mandated by OEMs and contract manufacturers. Selection of ROHS3 compliant parts ensures regulatory compliance and future supply chain compatibility.

Q: What does Moisture Sensitivity Level (MSL) mean for component handling?

A: MSL indicates the maximum time a component can be exposed to ambient conditions (typically 30°C, 85% relative humidity) before baking is required prior to soldering. MSL 3 (168 Hours) allows 168 hours of exposure; MSL 1 (Unlimited) has no time restriction. The NCV2575D2T-12R4G has MSL 1, providing more flexible handling. Most other parts have MSL 3, requiring baking if storage time exceeds 168 hours in high-humidity environments.

Q: Can I use the LM2596 series as a drop-in replacement if my application only requires 1A?

A: Electrically, yes. The LM2596S-12/NOPB and LM2596SX-12/NOPB can deliver 1A without issue. However, the 150kHz switching frequency requires recalculation of output filter components (inductor and capacitor values) compared to the 52kHz design. Additionally, the minimum input voltage is 4.5V instead of 4V. Verify that your input voltage floor meets the 4.5V minimum and that filter component recalculation is acceptable for your design timeline.