LF25CDT Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LF25CDT is a linear voltage regulator IC manufactured by STMicroelectronics, designed to deliver a fixed 2.5V output at 500mA in a DPAK surface mount package. This device functions as a positive fixed output regulator with integrated over-current and over-temperature protection, suitable for applications requiring stable low-voltage power delivery across an industrial temperature range of -40°C to 125°C.

The LF25CDT carries an obsolete product status. Identifying equivalent and substitute parts is necessary to ensure design continuity, maintain supply chain reliability, and support long-term production requirements for systems currently utilizing this regulator.

Substiute Parts

LF25CDT

STMicroelectronicsIn Stock: 10250LF25CDT Datasheet

Current PartRFQ

LF25CDT-TR

STMicroelectronicsIn Stock: 16946LF25CDT-TR Datasheet

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MC33275DT-2.5G

onsemiIn Stock: 952MC33275DT-2.5G Datasheet

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MC33275DT-2.5RKG

onsemiIn Stock: 2825MC33275DT-2.5RKG Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the LF25CDT is determined by strict alignment of electrical and mechanical parameters. The critical substitution criteria are:

Primary Matching Parameters:

• Fixed output voltage of 2.5V
• Output current capability (minimum 500mA for direct substitution)
• Maximum input voltage rating (minimum 16V)
• DPAK surface mount package (TO-252-3)
• Operating temperature range (-40°C to 125°C)
• Protection features (over-current and over-temperature)

Substitution Logic: Parts are grouped into two categories based on output current capacity. The LF25CDT-TR provides direct electrical equivalence with identical 500mA output current and active product status. The MC33275DT variants (MC33275DT-2.5G and MC33275DT-2.5RKG) operate at reduced output current (300mA) and lower maximum input voltage (13V), making them suitable only for applications with reduced current requirements.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: LF25CDT-TR

The LF25CDT-TR is the recommended substitute for the obsolete LF25CDT. This part maintains complete electrical equivalence with identical output voltage (2.5V), output current (500mA), input voltage rating (16V), and dropout voltage specifications. Both devices share the same DPAK package footprint and operating temperature range. The LF25CDT-TR carries active product status, ensuring long-term availability and supply chain continuity. Both parts are ROHS3 compliant and carry identical regulatory certifications (REACH Unaffected, EAR99 ECCN classification).

Secondary Substitutes: MC33275DT-2.5G and MC33275DT-2.5RKG

The onsemi MC33275DT variants are suitable substitutes only for applications where output current requirements do not exceed 300mA. These parts operate at reduced maximum input voltage (13V versus 16V) and feature lower quiescent current (200 µA versus 1 mA). The MC33275DT-2.5RKG is preferred over the MC33275DT-2.5G due to active product status. Both onsemi parts maintain DPAK package compatibility, identical operating temperature range, and equivalent protection features. These substitutes are appropriate for designs with reduced current demands or where lower quiescent current provides system-level benefits.

Frequently Asked Questions (FAQ)

Q: Can the LF25CDT-TR be used as a direct replacement for the LF25CDT?

A: Yes. The LF25CDT-TR provides complete electrical and mechanical compatibility. Both parts deliver 2.5V at 500mA with identical dropout voltage, input voltage rating, and DPAK package configuration. The primary advantage of LF25CDT-TR is its active product status, ensuring continued availability.

Q: What are the limitations of using MC33275DT variants as substitutes?

A: The MC33275DT-2.5G and MC33275DT-2.5RKG are limited to 300mA output current, compared to the LF25CDT's 500mA capability. Additionally, these parts have a maximum input voltage rating of 13V versus 16V for the LF25CDT. These substitutes are suitable only for applications with reduced current requirements and input voltage constraints.

Q: Are all substitute parts in the same package?

A: Yes. The LF25CDT, LF25CDT-TR, MC33275DT-2.5G, and MC33275DT-2.5RKG all use the TO-252-3 DPAK package with identical pinout and footprint, enabling direct PCB compatibility without layout modifications.

Q: Do the substitute parts meet the same compliance requirements?

A: Yes. All substitute parts listed are ROHS3 compliant, REACH unaffected, and carry EAR99 ECCN classification, matching the regulatory status of the original LF25CDT.

Q: What is the difference between LF25CDT-TR and MC33275DT-2.5RKG in terms of product availability?

A: The LF25CDT-TR carries active product status with higher inventory availability (16,929 units), while the MC33275DT-2.5RKG also carries active status with 2,800 units in stock. Both ensure long-term supply continuity, though LF25CDT-TR offers greater immediate availability.

Q: Can I use the MC33275DT-2.5G if my application requires 500mA output?

A: No. The MC33275DT-2.5G is rated for maximum 300mA output current. Using this part in a 500mA application would exceed its current rating and violate the device's electrical specifications.

Q: How do the PSRR specifications compare between the main part and substitutes?

A: The LF25CDT and LF25CDT-TR provide superior PSRR performance (82dB at 120Hz, declining to 65dB at 10kHz) compared to the MC33275DT variants (75dB at 120Hz). Applications requiring higher power supply rejection ratio should prioritize the STMicroelectronics parts.