US1JFA Equivalent & Substitute Parts

Part Overview

The US1JFA is a general-purpose rectifier diode manufactured by onsemi, rated for 600 V DC reverse voltage and 1 A average rectified current in a surface mount SOD-123FA package. This device is classified as "Not For New Designs," indicating it has been superseded in onsemi's product portfolio. Identifying equivalent substitute parts is necessary for applications requiring continued sourcing, legacy system maintenance, or design flexibility where alternative manufacturers' components meet the same electrical and mechanical specifications.

Substiute Parts

US1JFA

onsemiIn Stock: 35213US1JFA Datasheet

Current PartRFQ

VS-1EFU06-M3/I

Vishay General Semiconductor - Diodes DivisionIn Stock: 4375VS-1EFU06-M3/I Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the US1JFA is determined by equivalence in the following critical parameters:

• Voltage Rating: 600 V DC reverse voltage (Vr) maximum
• Current Rating: 1 A average rectified current (Io)
• Speed Classification: Fast recovery diode with reverse recovery time ≤ 500 ns for currents > 200 mA
• Mounting Technology: Surface mount configuration
• Temperature Range: Operating junction temperature capability
• Regulatory Compliance: RoHS3 compliance and REACH status

The VS-1EFU06-M3/I from Vishay General Semiconductor - Diodes Division satisfies all substitution criteria. Both devices operate at identical voltage and current ratings, maintain fast recovery characteristics, and are surface mount components with equivalent regulatory compliance. Package geometry differences (SOD-123FA versus DO-219AB) require physical layout verification but do not affect electrical substitutability.

Parameter Comparison

Engineering Selection Recommendations

The VS-1EFU06-M3/I is a direct electrical equivalent to the US1JFA for applications requiring 600 V, 1 A fast recovery rectification. Both components meet ROHS3 compliance and REACH requirements, ensuring regulatory compatibility in end-use applications.

The VS-1EFU06-M3/I offers the following advantages:

• Active Product Status: Vishay maintains this component in active production, ensuring long-term availability and supply chain stability compared to the onsemi US1JFA, which is not recommended for new designs.
• Improved Performance Characteristics: Lower forward voltage drop (1.2 V versus 1.7 V at 1 A) and faster reverse recovery time (32 ns versus 75 ns) reduce power dissipation and switching losses.
• Extended Temperature Range: Maximum junction temperature of 175°C versus 150°C provides additional thermal margin in high-temperature applications.
• Lower Reverse Leakage: 3 µA at 600 V versus 5 µA reduces standby current consumption.

Package geometry differs between the two devices (SOD-123FA versus DO-219AB). Physical layout and footprint compatibility must be evaluated for the specific application before implementation.

Frequently Asked Questions (FAQ)

Q: Can the VS-1EFU06-M3/I directly replace the US1JFA without circuit modification?

A: Electrical substitution is valid. Both devices share identical voltage and current ratings, fast recovery characteristics, and regulatory compliance. However, package geometry differs (SOD-123FA versus DO-219AB), requiring PCB footprint and layout verification. No circuit modifications are necessary if physical placement is accommodated.

Q: What is the significance of the "Not For New Designs" status on the US1JFA?

A: This designation indicates that onsemi has discontinued active development and marketing of this component. While existing inventory may be available, the manufacturer does not recommend its use in new product designs. The VS-1EFU06-M3/I, with active product status, is the appropriate choice for new applications.

Q: How do the forward voltage drop differences affect circuit performance?

A: The VS-1EFU06-M3/I exhibits a lower forward voltage drop (1.2 V versus 1.7 V at 1 A). This 0.5 V reduction decreases power dissipation in the diode and improves overall circuit efficiency. Applications sensitive to voltage drop or thermal management benefit from this characteristic.

Q: Are there package compatibility considerations for PCB assembly?

A: Yes. The US1JFA uses SOD-123FA packaging, while the VS-1EFU06-M3/I uses DO-219AB (SMF) packaging. These packages have different physical dimensions and footprints. PCB layout, solder pad geometry, and component placement must be verified for compatibility. Consult package datasheets for precise dimensional specifications.

Q: Do both devices meet the same regulatory and compliance standards?

A: Yes. Both the US1JFA and VS-1EFU06-M3/I are ROHS3 compliant, REACH unaffected, and classified under ECCN EAR99 with identical HTSUS codes. Regulatory requirements are satisfied by either component.

Q: What is the practical difference in reverse recovery time between these devices?

A: The VS-1EFU06-M3/I has a reverse recovery time of 32 ns compared to 75 ns for the US1JFA. Faster recovery reduces switching losses and electromagnetic interference in high-frequency applications. This improvement is particularly beneficial in power supply circuits and switching applications operating above 100 kHz.