LM2574N-3.3 Equivalent & Substitute Parts

Part Overview

The LM2574N-3.3 is a buck switching regulator IC from Texas Instruments' SIMPLE SWITCHER® series, designed for step-down voltage conversion with a fixed 3.3V output. This through-hole 8-DIP package device delivers 500mA output current across an input voltage range of 4V to 40V, operating at a 52kHz switching frequency without synchronous rectification.

The LM2574N-3.3 is classified as obsolete. Identifying equivalent substitute parts is necessary to ensure design continuity, maintain supply chain reliability, and support legacy system maintenance or redesigns requiring this functional specification.

Substiute Parts

LM2574N-3.3

Texas InstrumentsIn Stock: 3465LM2574N-3.3 Datasheet

Current PartRFQ

LM2574N-3.3/NOPB

Texas InstrumentsIn Stock: 2922LM2574N-3.3/NOPB Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LM2574N-3.3 are identified based on strict electrical and mechanical parameter matching:

Critical Matching Parameters:

• Output voltage: 3.3V fixed
• Output current capability: 500mA
• Input voltage range: 4V to 40V minimum
• Switching topology: Buck (step-down)
• Package: 8-DIP through-hole form factor
• Operating temperature range: -40°C to 125°C
• Switching frequency: 52kHz

The LM2574N-3.3/NOPB qualifies as a direct substitute because it maintains identical electrical specifications and physical packaging while offering improved product status and compliance certification.

Parameter Comparison

Engineering Selection Recommendations

The LM2574N-3.3/NOPB is the direct substitute for the obsolete LM2574N-3.3. Both parts share identical electrical performance and physical packaging specifications. The primary distinction is product lifecycle status and regulatory compliance:

The LM2574N-3.3/NOPB maintains active product status with Texas Instruments, ensuring continued availability and technical support. This part carries ROHS3 compliance certification, meeting current environmental and material restriction requirements, whereas the original LM2574N-3.3 is RoHS non-compliant.

For new designs or system updates, the LM2574N-3.3/NOPB is the appropriate selection. For legacy system maintenance requiring exact part matching, the LM2574N-3.3 remains functionally equivalent where regulatory compliance is not a constraint.

Frequently Asked Questions (FAQ)

Q: Can the LM2574N-3.3/NOPB be used as a direct replacement for the LM2574N-3.3?

A: Yes. Both parts deliver identical electrical performance: 3.3V fixed output, 500mA current capacity, 4V to 40V input range, and 52kHz switching frequency. The 8-DIP through-hole package is identical, enabling direct PCB substitution without circuit modification.

Q: What does the "/NOPB" suffix indicate?

A: The "/NOPB" suffix designates lead-free, RoHS3-compliant packaging. This indicates the part meets current environmental and material restriction standards. The electrical and functional specifications remain unchanged from the base part number.

Q: Why is the LM2574N-3.3 listed as obsolete?

A: Product obsolescence reflects Texas Instruments' lifecycle management. The LM2574N-3.3/NOPB represents the current active equivalent, incorporating modern compliance standards while maintaining the same functional design.

Q: Are there any differences in thermal performance between these parts?

A: No. Both parts operate across the identical temperature range of -40°C to 125°C (junction temperature) and share the same thermal characteristics within the 8-DIP package.

Q: Can these parts be used interchangeably in existing PCB designs?

A: Yes. The identical package footprint (8-DIP, 0.300" spacing) and pinout enable direct board-level substitution. No PCB layout modifications are required.