1N459A_L99Z Equivalent & Substitute Parts

Part Overview

The 1N459A_L99Z is a general-purpose rectifier diode manufactured by onsemi, rated for 200 V DC reverse voltage and 500 mA average rectified current in a DO-35 through-hole package. This component is classified as obsolete, which necessitates identification of equivalent and substitute parts for ongoing design support and procurement continuity. The diode operates with standard recovery characteristics and is suitable for general rectification applications requiring moderate voltage and current ratings.

Substiute Parts

1N459A_L99Z

onsemiIn Stock: 8031N459A_L99Z Datasheet

Current PartRFQ

1N459A

Microchip TechnologyIn Stock: 8361N459A Datasheet

SimilarRFQ

1N459-T50R

Fairchild SemiconductorIn Stock: 611371N459-T50R Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 1N459A_L99Z is determined by the following critical parameters:

Primary Substitution Criteria:

• Voltage - DC Reverse (Vr) (Max): Must equal or exceed 200 V
• Current - Average Rectified (Io): Must equal or exceed 500 mA
• Package / Case: Must be DO-35 or DO-204AH (axial through-hole)
• Mounting Type: Must be through-hole compatible

Secondary Compatibility Factors:

• Voltage - Forward (Vf) (Max) @ If: 1 V @ 100 mA
• Speed: Standard recovery characteristics
• Operating Temperature - Junction: Must support 175°C maximum

Substitute parts are grouped into two categories:

Parametric Equivalent: Parts matching all primary criteria with identical electrical performance specifications.

Similar Substitute: Parts matching voltage and package requirements but with reduced current rating, suitable only where application current demands do not exceed the substitute part's rating.

Parameter Comparison

Engineering Selection Recommendations

1N459-T50R (Fairchild Semiconductor) - Parametric Equivalent

The 1N459-T50R is a parametric equivalent to the 1N459A_L99Z, matching all primary electrical specifications: 200 V reverse voltage, 500 mA average rectified current, standard recovery speed, and identical forward voltage characteristics. Both parts share the same DO-35 package configuration and maximum junction temperature rating of 175°C. Although classified as obsolete, this part maintains 61,105 units in current inventory stock. This substitute is suitable for direct replacement in applications requiring full 500 mA current capacity.

1N459A (Microchip Technology) - Similar Substitute with Current Derating

The 1N459A from Microchip Technology matches the 200 V reverse voltage rating and DO-35 package requirements but is rated for 150 mA average rectified current, representing a 70% reduction from the original 500 mA specification. This part is currently active in production status, ensuring long-term availability. The maximum junction temperature is limited to 150°C, which is 25°C lower than the original specification. Reverse leakage current is specified at 1 µA @ 200 V, compared to 25 nA @ 175 V for the original part. This substitute is applicable only in applications where the circuit current demand does not exceed 150 mA and where the reduced temperature rating is acceptable. The part carries RoHS non-compliant status.

Frequently Asked Questions (FAQ)

Q: Can the 1N459A (Microchip Technology) be used as a direct replacement for the 1N459A_L99Z?

A: The 1N459A is not a direct replacement due to current rating mismatch. The Microchip part is rated for 150 mA average rectified current, while the original part is rated for 500 mA. Use this substitute only in applications where circuit current does not exceed 150 mA. Additionally, the maximum junction temperature is reduced to 150°C.

Q: What is the difference between the 1N459-T50R and the original 1N459A_L99Z?

A: The 1N459-T50R is a parametric equivalent with identical electrical specifications: 200 V reverse voltage, 500 mA average rectified current, 1 V forward voltage @ 100 mA, and 175°C maximum junction temperature. Both parts use the DO-35 package. The primary difference is manufacturer (Fairchild Semiconductor versus onsemi) and product status (both obsolete).

Q: Are all three parts compatible with the same PCB footprint?

A: Yes. All three parts use the DO-35 axial through-hole package (DO-204AH), which provides identical physical dimensions and pin spacing. PCB footprints designed for the 1N459A_L99Z accommodate all listed substitutes without modification.

Q: What is the significance of the "Standard Recovery" speed specification?

A: Standard recovery speed (>500 ns for currents > 200 mA) indicates the diode's switching characteristics. Both the 1N459A_L99Z and 1N459-T50R share this specification, making them suitable for identical application classes. The Microchip 1N459A is classified as "Small Signal," indicating different recovery behavior suitable only for lower current applications.

Q: Why does the Microchip 1N459A show higher reverse leakage current?

A: The Microchip part specifies 1 µA @ 200 V, while the original specifies 25 nA @ 175 V. These measurements are taken at different voltage and temperature conditions. The higher leakage value at the higher voltage point reflects the part's leakage characteristics under those specific test conditions and does not necessarily indicate inferior performance in all operating scenarios.

Q: Is inventory availability a factor in part selection?

A: Inventory levels are provided for reference: 1N459A_L99Z has 776 units, 1N459A (Microchip) has 768 units, and 1N459-T50R has 61,105 units in stock. However, part selection should be based on electrical compatibility and application requirements rather than inventory status alone.