LS4448W Equivalent & Substitute Parts

Part Overview

The LS4448W is a fast recovery rectifier diode manufactured by Diodes Incorporated, rated for 100 V DC reverse voltage and 250 mA average rectified current in a 1206 surface mount package. This part is classified as obsolete, necessitating identification of active equivalent components for new designs and ongoing production requirements. The LS4448W operates across a junction temperature range of -65°C to 175°C and complies with RoHS3 and REACH standards.

Substiute Parts

LS4448W

Diodes IncorporatedIn Stock: 1043LS4448W Datasheet

Current PartRFQ

1N4448W-7-F

Diodes IncorporatedIn Stock: 10002301N4448W-7-F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LS4448W is determined by the following electrical and mechanical parameters:

Critical Matching Parameters:

• Current - Average Rectified (Io): 250 mA
• Voltage - Forward (Vf) (Max) @ If: 1.25 V @ 150 mA
• Speed Classification: Fast Recovery ≤ 500ns, > 200mA (Io)
• Reverse Recovery Time (trr): 4 ns
• Capacitance @ Vr, F: 4 pF @ 0V, 1MHz
• Mounting Type: Surface Mount
• RoHS3 Compliance

Allowable Variation Parameters:

• Voltage - DC Reverse (Vr) (Max): Equal or greater than 100 V
• Current - Reverse Leakage @ Vr: Equal or lower than 5 µA @ 75 V
• Operating Temperature - Junction: Equal or greater than -65°C to 175°C range
• Package / Case: Alternative surface mount packages acceptable if footprint compatibility is verified

The substitute part 1N4448W-7-F meets the critical electrical specifications while operating at a reduced maximum reverse voltage of 75 V. This part is classified as active and maintains all fast recovery diode characteristics required for equivalent functionality in applications where the 100 V rating is not mandatory.

Parameter Comparison

Engineering Selection Recommendations

The 1N4448W-7-F is the manufacturer-recommended substitute for the obsolete LS4448W. Selection of this substitute is appropriate based on the following factors:

Product Status Consideration: The LS4448W is classified as obsolete, while the 1N4448W-7-F maintains active product status with high inventory availability (1,000,200 pieces). This ensures long-term supply continuity and manufacturing support.

Compliance Alignment: Both parts maintain RoHS3 compliance and REACH unaffected status, satisfying regulatory requirements for new designs and production environments.

Electrical Equivalence: The substitute part maintains identical specifications for current rating (250 mA), forward voltage (1.25 V @ 150 mA), fast recovery speed classification (≤ 500ns), and reverse recovery time (4 ns). These parameters define the functional performance of the rectifier diode in circuit applications.

Voltage Rating Consideration: The 1N4448W-7-F operates at a maximum reverse voltage of 75 V compared to the LS4448W's 100 V rating. This reduction is acceptable for applications where the circuit design does not require the full 100 V reverse voltage capability.

Temperature Range Consideration: The substitute part operates to a maximum junction temperature of 150°C, compared to the original part's 175°C. Applications requiring operation above 150°C require verification against specific circuit thermal requirements.

Package Transition: The substitute part uses SOD-123 packaging instead of the original 1206 package. PCB layout and footprint modifications are required for implementation.

Frequently Asked Questions (FAQ)

Q: Can the 1N4448W-7-F directly replace the LS4448W without circuit modification?

A: Electrical substitution is valid for applications where the circuit reverse voltage does not exceed 75 V and maximum junction temperature does not exceed 150°C. PCB layout modification is required due to package change from 1206 to SOD-123.

Q: What is the primary difference between these two parts?

A: The LS4448W is rated for 100 V reverse voltage in a 1206 package and is obsolete. The 1N4448W-7-F is rated for 75 V reverse voltage in a SOD-123 package and maintains active product status. All fast recovery diode electrical characteristics remain identical.

Q: Is the lower reverse voltage rating of the 1N4448W-7-F a limitation?

A: The 75 V rating is sufficient for applications designed for this voltage level. Applications requiring 100 V reverse voltage capability must verify that circuit conditions do not exceed 75 V during normal operation or fault conditions.

Q: Does the SOD-123 package affect circuit performance?

A: SOD-123 and 1206 packages are both surface mount technologies with equivalent electrical performance. Package selection affects PCB layout, thermal dissipation characteristics, and board space requirements. Thermal performance differences between packages must be evaluated for high-current applications.

Q: Are there temperature-related limitations with the 1N4448W-7-F?

A: The substitute part is rated to 150°C maximum junction temperature compared to the original 175°C. Applications operating near or above 150°C require thermal analysis to confirm the substitute part remains within acceptable operating limits.

Q: What is the reverse leakage current difference between these parts?

A: The LS4448W specifies 5 µA reverse leakage at 75 V, while the 1N4448W-7-F specifies 2.5 µA at the same voltage. The lower leakage of the substitute part provides improved performance in this parameter.

Q: Are both parts RoHS3 compliant?

A: Yes, both the LS4448W and 1N4448W-7-F are RoHS3 compliant and REACH unaffected, meeting current environmental and regulatory standards.