LM2575SX-12 Equivalent & Substitute Parts

Part Overview

The LM2575SX-12 is a buck switching regulator IC from Texas Instruments, classified as a Power Management (PMIC) component. It delivers a fixed 12V output at 1A from an input range of 4V to 40V, operating at a switching frequency of 52kHz. The device is packaged in TO-263-6 (D2PAK with 5 leads plus tab) and is rated for operation from -40°C to 125°C junction temperature.

The LM2575SX-12 is currently listed as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or maintenance requirements.

Key Parameters

Parameter	Value
Manufacturer	Texas Instruments
Function	Step-Down (Buck)
Output Voltage	12V Fixed
Output Current	1A
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)
Synchronous Rectifier	No
Mounting Type	Surface Mount

Substitute Part Grouping Explanation

Substitution for the LM2575SX-12 is determined by the following critical parameters:

Output Voltage: Must be fixed at 12V
Output Current: Minimum 1A (higher current ratings are acceptable for drop-in replacement)
Input Voltage Range: Must accommodate 4V to 40V minimum
Package Type: TO-263-6 or D2PAK-5 (pin-compatible)
Switching Frequency: 52kHz (standard for this topology)
Topology: Buck (step-down) configuration
Operating Temperature Range: -40°C to 125°C or wider

Substitute parts are grouped into two categories:

Direct Equivalents (1A Output Current): Parts with identical 1A output current rating, same package, and matching electrical specifications.

Higher Current Alternatives (3A Output Current): Parts with 3A output capability in the same package. These provide enhanced current handling while maintaining full backward compatibility with 1A designs.

Parameter Comparison

Part Number	Manufacturer	Output Current	Input Voltage (Min)	Input Voltage (Max)	Package	Product Status	RoHS Status
LM2575SX-12	Texas Instruments	1A	4V	40V	TO-263-6	Obsolete	Non-compliant
LM2575SX-12/NOPB	Texas Instruments	1A	4V	40V	TO-263-6	Active	ROHS3 Compliant
LM2575-12WU	Microchip Technology	1A	4V	40V	TO-263-6	Active	ROHS3 Compliant
LM2575D2T-12R4G	onsemi	1A	4.75V	40V	D2PAK-5	Active	ROHS3 Compliant
NCV2575D2T-12R4G	onsemi	1A	4.75V	40V	D2PAK-5	Obsolete	ROHS3 Compliant
LM2576-12WU	Microchip Technology	3A	4V	40V	TO-263-6	Active	ROHS3 Compliant
LM2576-12WU-TR	Microchip Technology	3A	4V	40V	TO-263-6	Active	ROHS3 Compliant
LM2576D2TR4-012G	onsemi	3A	7V	40V	D2PAK-5	Active	ROHS3 Compliant

Engineering Selection Recommendations

For Direct Replacement (1A Applications)

LM2575SX-12/NOPB is the primary direct equivalent. It maintains identical electrical specifications and package configuration while offering active product status and ROHS3 compliance, addressing the obsolescence of the original LM2575SX-12.

LM2575-12WU (Microchip Technology) and LM2575D2T-12R4G (onsemi) are functionally equivalent alternatives. Both are active products with ROHS3 compliance. The onsemi variant specifies a minimum input voltage of 4.75V versus 4V for the Microchip part; this difference is acceptable for most applications but should be verified against specific circuit requirements.

NCV2575D2T-12R4G is not recommended for new designs despite ROHS3 compliance, as it carries obsolete product status.

For Higher Current Applications (3A Capability)

LM2576-12WU and LM2576-12WU-TR (Microchip Technology) provide 3A output current in the same TO-263-6 package. These are suitable for designs requiring enhanced current capacity while maintaining full pin compatibility. The -TR variant specifies tape and reel packaging; the non-TR variant is supplied in tube packaging.

LM2576D2TR4-012G (onsemi) offers 3A output in D2PAK-5 package with active status and ROHS3 compliance. Note that this variant specifies a minimum input voltage of 7V, which may limit applicability in designs requiring operation below 7V input.

Compliance Considerations

All recommended active substitutes are ROHS3 compliant, addressing regulatory requirements for new production. The original LM2575SX-12 is non-compliant and should not be used in new designs subject to RoHS regulations.

Frequently Asked Questions (FAQ)

Q: Can I use LM2576 (3A) parts as a direct replacement for LM2575 (1A) designs?

A: Yes. The LM2576 series maintains identical pin configuration, package type, and electrical interface. The higher current rating (3A versus 1A) does not prevent operation in 1A applications. The device will operate within its rated specifications at lower current levels. No circuit modifications are required.

Q: What is the difference between TO-263-6 and D2PAK-5 packages?

A: Both designations refer to the same physical package format (5 leads plus tab). TO-263-6 and D2PAK-5 are equivalent package types with identical pin layouts and thermal characteristics. Parts specified with either designation are mechanically and electrically interchangeable.

Q: Why do some substitutes specify 4.75V minimum input while others specify 4V?

A: This reflects manufacturer-specific design margins and characterization. Both specifications accommodate the intended 4V to 40V input range for practical applications. If your circuit operates below 4.75V, select parts specifying 4V minimum input (LM2575SX-12/NOPB or LM2575-12WU).

Q: Is the LM2576D2TR4-012G suitable for designs requiring 4V input operation?

A: No. This part specifies a 7V minimum input voltage, which exceeds the original LM2575SX-12 specification of 4V minimum. Use this part only in applications where input voltage remains at or above 7V.

Q: What packaging options are available for substitutes?

A: Microchip Technology supplies LM2575-12WU and LM2576-12WU in tube packaging, while LM2576-12WU-TR is supplied in tape and reel format. onsemi parts are supplied in tape and reel. Texas Instruments LM2575SX-12/NOPB is available in cut tape and digi-reel packaging. Select based on your procurement and assembly requirements.

Q: Are all recommended substitutes ROHS3 compliant?

A: All active product substitutes listed are ROHS3 compliant. The original LM2575SX-12 is non-compliant. For applications subject to RoHS regulations, use only the compliant alternatives.

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