LM2576-3.3BU TR Equivalent & Substitute Parts

Part Overview

The LM2576-3.3BU TR is a buck switching regulator IC manufactured by Microchip Technology, designed for positive fixed 3.3V output applications with 3A output current capability. This part operates across a 4V to 40V input voltage range with a switching frequency of 52kHz and is housed in a TO-263-6 D2PAK package with 5 leads plus tab.

The LM2576-3.3BU TR is classified as obsolete. Identifying equivalent and substitute parts is necessary to ensure design continuity, maintain supply chain reliability, and support ongoing production requirements for applications currently utilizing this component.

Key Parameters

Parameter	Value
Manufacturer	Microchip Technology
Function	Step-Down (Buck)
Output Voltage	3.3V Fixed
Output Current	3A
Input Voltage Range	4V to 40V
Switching Frequency	52kHz
Package Type	TO-263-6 D2PAK (5 Leads + Tab)
Operating Temperature	-40°C to 125°C (TJ)
Mounting Type	Surface Mount
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution eligibility for the LM2576-3.3BU TR is determined by the following critical parameters:

Output voltage: 3.3V fixed
Package type: TO-263-6 D2PAK (5 Leads + Tab)
Operating temperature range: -40°C to 125°C
Mounting type: Surface Mount
Output configuration: Positive

Substitute parts are grouped into two categories based on output current capability and input voltage specifications:

Category 1: Direct Current Equivalent (3A Output) LM2576-3.3WU-TR maintains identical 3A output current, making it a direct functional replacement with improved product status (Active vs. Obsolete).

Category 2: Reduced Current Substitutes (1A Output) Texas Instruments LM2575 and LM2591 series parts provide 1A output current. These are suitable for applications where the full 3A capacity is not required. The LM2591 series extends input voltage capability to 60V maximum, while LM2575 series maintains the 40V maximum input specification.

Parameter Comparison

Parameter	LM2576-3.3BU TR	LM2576-3.3WU-TR	LM2575S-3.3/NOPB	LM2575SX-3.3/NOPB	LM2591HVS-3.3/NOPB	LM2591HVSX-3.3/NOPB	TL2575-33IKTTR	TL2575HV-33IKTTR
Manufacturer	Microchip	Microchip	Texas Instruments	Texas Instruments	Texas Instruments	Texas Instruments	Texas Instruments	Texas Instruments
Output Voltage	3.3V	3.3V	3.3V	3.3V	3.3V	3.3V	3.3V	3.3V
Output Current	3A	3A	1A	1A	1A	1A	1A	1A
Input Voltage (Min)	4V	4V	4V	4V	4.5V	4.5V	4.75V	4.75V
Input Voltage (Max)	40V	40V	40V	40V	60V	60V	40V	60V
Switching Frequency	52kHz	52kHz	52kHz	52kHz	150kHz	150kHz	52kHz	52kHz
Package Type	TO-263-6 D2PAK	TO-263-6 D2PAK	TO-263-6 D2PAK	TO-263-6 D2PAK	TO-263-6 D2PAK	TO-263-6 D2PAK	TO-263-6 D2PAK	TO-263-6 D2PAK
Operating Temperature	-40°C to 125°C	-40°C to 125°C	-40°C to 125°C	-40°C to 125°C	-40°C to 125°C	-40°C to 125°C	-40°C to 125°C	-40°C to 125°C
RoHS Status	Non-compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Product Status	Obsolete	Active	Active	Active	Active	Active	Active	Active

Engineering Selection Recommendations

Primary Recommendation: LM2576-3.3WU-TR

The LM2576-3.3WU-TR is the direct equivalent replacement for the obsolete LM2576-3.3BU TR. Both parts share identical electrical specifications including 3A output current, 52kHz switching frequency, and 4V to 40V input voltage range. The LM2576-3.3WU-TR maintains active product status and achieves ROHS3 compliance, addressing regulatory requirements while preserving full functional compatibility. This part is recommended for applications requiring no design modifications.

Secondary Recommendations: Texas Instruments LM2575 Series

The LM2575S-3.3/NOPB and LM2575SX-3.3/NOPB are suitable substitutes for applications where 1A output current meets design requirements. Both maintain the 52kHz switching frequency and 4V to 40V input voltage range. These parts are ROHS3 compliant and carry active product status. The LM2575SX-3.3/NOPB offers higher inventory availability (17,530 units) compared to the tube-packaged LM2575S-3.3/NOPB variant.

Extended Input Voltage Option: Texas Instruments LM2591 Series

The LM2591HVS-3.3/NOPB and LM2591HVSX-3.3/NOPB extend maximum input voltage to 60V while maintaining 1A output current and 3.3V fixed output. These parts operate at 150kHz switching frequency, enabling smaller external component sizing. Selection of LM2591 series is appropriate for applications requiring higher input voltage tolerance or where switching frequency characteristics provide design advantages.

Alternative: Texas Instruments TL2575 Series

The TL2575-33IKTTR and TL2575HV-33IKTTR provide 1A output current with 52kHz switching frequency. The TL2575-33IKTTR maintains 4V to 40V input range, while TL2575HV-33IKTTR extends to 60V maximum input. Both are ROHS3 compliant with active product status.

Frequently Asked Questions (FAQ)

Q: Can LM2576-3.3WU-TR directly replace LM2576-3.3BU TR without circuit modifications?

A: Yes. The LM2576-3.3WU-TR is electrically and mechanically identical to the LM2576-3.3BU TR. Both parts feature 3A output current, 52kHz switching frequency, TO-263-6 D2PAK packaging, and identical input/output voltage specifications. No circuit modifications are required.

Q: What is the primary difference between LM2576 and LM2575 series substitutes?

A: The LM2576-3.3WU-TR provides 3A output current, while LM2575 series parts deliver 1A output current. Selection depends on application current requirements. If the design draws less than 1A, LM2575 series parts are suitable. If 3A capacity is required, LM2576-3.3WU-TR is the appropriate choice.

Q: Why do LM2591 series parts operate at 150kHz instead of 52kHz?

A: The LM2591 series is designed with a higher switching frequency of 150kHz. This characteristic enables use of smaller external inductors and capacitors in the power supply circuit. The higher frequency does not affect output voltage regulation or compatibility with standard TO-263-6 D2PAK packaging.

Q: Are all substitute parts ROHS3 compliant?

A: All recommended substitute parts except the original LM2576-3.3BU TR are ROHS3 compliant. The LM2576-3.3BU TR is classified as RoHS non-compliant. If RoHS compliance is a design requirement, the LM2576-3.3WU-TR or any Texas Instruments substitute is appropriate.

Q: What is the difference between tube and tape & reel packaging options?

A: Tube packaging (LM2575S-3.3/NOPB, LM2591HVS-3.3/NOPB) is suitable for lower-volume applications and manual assembly. Tape & Reel (TR) and Cut Tape (CT) & Digi-Reel packaging options (LM2575SX-3.3/NOPB, LM2591HVSX-3.3/NOPB, TL2575-33IKTTR, TL2575HV-33IKTTR) are designed for automated pick-and-place assembly. Packaging selection depends on production volume and assembly equipment capabilities.

Q: Can LM2591 series parts be used in applications designed for LM2575 series?

A: Yes, with design considerations. LM2591 series parts are pin-compatible and functionally compatible with LM2575 series in TO-263-6 D2PAK packaging. The higher 150kHz switching frequency of LM2591 series may allow optimization of external component values. Input voltage range extends to 60V on LM2591HV variants, providing additional design flexibility for higher input voltage applications.

Q: What inventory considerations apply to substitute part selection?

A: LM2575SX-3.3/NOPB offers the highest inventory availability at 17,530 units. LM2576-3.3WU-TR provides 3,505 units. Other substitutes range from 1,011 to 3,697 units. Inventory levels should be evaluated against production volume and supply chain requirements.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message