1N4148 Equivalent & Substitute Parts

Part Overview

The 1N4148 is a general-purpose small-signal diode rated for 75 V DC reverse voltage and 150 mA average rectified current in a DO-35 through-hole package. This device is classified as obsolete, indicating that direct procurement from the original manufacturer (Micro Commercial Co) may be limited. Equivalent and substitute parts are necessary to maintain design continuity and ensure component availability for new production runs, repairs, and legacy system support.

Key Parameters

Parameter	Value	Unit
Voltage - DC Reverse (Vr) (Max)	75	V
Current - Average Rectified (Io)	150	mA
Voltage - Forward (Vf) (Max) @ If	1 V @ 10 mA	V
Reverse Recovery Time (trr)	4	ns
Current - Reverse Leakage @ Vr	5 µA @ 75 V	µA
Mounting Type	Through Hole	—
Package / Case	DO-204AH, DO-35, Axial	—
Operating Temperature - Junction	-65 to 175	°C
Technology	Standard	—

Substitute Part Grouping Explanation

Substitution of the 1N4148 is determined by the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

Voltage - DC Reverse (Vr) (Max): Must equal or exceed 75 V
Current - Average Rectified (Io): Must equal or exceed 150 mA
Reverse Recovery Time (trr): Must equal or be faster than 4 ns
Mounting Type: Must be Through Hole
Package / Case: Must be DO-204AH, DO-35, or Axial equivalent
Forward Voltage (Vf): Must not exceed 1 V @ 10 mA

Substitution Categories:

Direct Equivalents meet all primary criteria with identical or superior electrical performance and active product status. These parts are recommended for new designs and production.

Functional Equivalents meet all primary criteria but may have different product status (obsolete or discontinued). These parts are suitable for legacy system support and repairs where exact specifications are required.

Enhanced Substitutes exceed one or more primary parameters (higher voltage rating, higher current capacity, or improved temperature range) while maintaining compatibility. These parts provide design margin and are suitable when higher performance is acceptable.

Parameter Comparison

Part Number	Manufacturer	Vr (Max) [V]	Io [mA]	Vf (Max) @ If [V]	trr [ns]	Ir @ Vr [µA]	Tj (Max) [°C]	Product Status	RoHS Status
1N4148	Micro Commercial Co	75	150	1 @ 10 mA	4	5 @ 75 V	175	Obsolete	Non-compliant
1N4448	Microchip Technology	75	200	1 @ 100 mA	4	25 nA @ 20 V	150	Discontinued	Non-compliant
1N4454 TR PBFREE	Central Semiconductor Corp	75	150	1 @ 10 mA	4	100 nA @ 50 V	200	Active	ROHS3 Compliant
1N4454-TAP	Vishay General Semiconductor - Diodes Division	75	150	1 @ 10 mA	4	5 µA @ 75 V	175	Active	ROHS3 Compliant
1N4454-TR	Vishay General Semiconductor - Diodes Division	75	150	1 @ 10 mA	4	5 µA @ 75 V	175	Active	ROHS3 Compliant
1N4148-1	Microchip Technology	75	200	1.2 @ 100 mA	20	500 nA @ 75 V	175	Active	Non-compliant
1N4148-G	Comchip Technology	75	150	1 @ 10 mA	—	5 µA @ 75 V	200	Obsolete	ROHS3 Compliant
1N4148-T26A	onsemi	100	200	1 @ 10 mA	4	5 µA @ 75 V	175	Active	ROHS3 Compliant
1N4148-T50A	Fairchild Semiconductor	100	200	1 @ 10 mA	4	5 µA @ 75 V	175	Active	—
1N4148-T50R	onsemi	100	200	1 @ 10 mA	4	5 µA @ 75 V	175	Active	ROHS3 Compliant
1N4148-TAP	Vishay General Semiconductor - Diodes Division	75	300	1 @ 10 mA	8	25 nA @ 20 V	150	Active	ROHS3 Compliant

Engineering Selection Recommendations

Recommended Direct Substitutes (Active Status, RoHS3 Compliant):

The 1N4454-TAP and 1N4454-TR from Vishay General Semiconductor - Diodes Division are the primary recommended substitutes for new designs and production. Both parts meet all electrical specifications of the original 1N4148, maintain identical voltage and current ratings, and offer active product status with ROHS3 compliance. The 1N4454-TAP is supplied in Tape & Box packaging, while the 1N4454-TR is supplied in Tape & Reel packaging. Selection between these two depends on assembly process requirements.

Alternative Direct Substitute (Active Status, RoHS3 Compliant):

The 1N4454 TR PBFREE from Central Semiconductor Corp is an active alternative with identical electrical specifications. This part offers an extended maximum junction temperature of 200°C compared to the original 175°C specification, providing additional thermal margin. ROHS3 compliance is confirmed.

Enhanced Substitutes (Higher Voltage Rating, Active Status, RoHS3 Compliant):

The 1N4148-T26A and 1N4148-T50R from onsemi, and 1N4148-T50A from Fairchild Semiconductor, provide enhanced voltage ratings of 100 V while maintaining the same 150 mA current capacity and 4 ns recovery time. These parts are suitable for applications where higher reverse voltage margin is required. All three maintain active product status and ROHS3 compliance (where specified).

Functional Equivalent (Obsolete Status, RoHS3 Compliant):

The 1N4148-G from Comchip Technology meets all electrical specifications and offers ROHS3 compliance with an extended temperature range to 200°C. However, this part is classified as obsolete and should be used only for legacy system repairs where exact specification matching is critical.

Not Recommended:

The 1N4448 from Microchip Technology and 1N4148-1 from Microchip Technology do not meet the recommended criteria. The 1N4448 is discontinued at DiGi Electronics with a reduced maximum junction temperature of 150°C. The 1N4148-1 exhibits degraded reverse recovery time (20 ns versus 4 ns) and higher reverse leakage current (500 nA versus 5 µA), making it unsuitable as a direct substitute.

Frequently Asked Questions (FAQ)

Q: Can the 1N4454-TAP and 1N4454-TR be used interchangeably with the 1N4148?

A: Yes. Both parts meet all electrical specifications of the 1N4148, including voltage rating (75 V), current capacity (150 mA), forward voltage (1 V @ 10 mA), and reverse recovery time (4 ns). The difference between these two parts is packaging: 1N4454-TAP is supplied in Tape & Box format, while 1N4454-TR is supplied in Tape & Reel format. Selection depends on your assembly process requirements.

Q: What is the difference between the 1N4148-T50R and the original 1N4148?

A: The 1N4148-T50R has a higher reverse voltage rating of 100 V compared to the original 75 V specification. All other electrical parameters are identical: 150 mA current capacity, 1 V forward voltage @ 10 mA, and 4 ns reverse recovery time. The higher voltage rating provides additional design margin and is suitable for applications where higher reverse voltage stress may occur.

Q: Why is the 1N4148-TAP from Vishay not recommended as a direct substitute?

A: The 1N4148-TAP has a higher current rating (300 mA versus 150 mA) and a slower reverse recovery time (8 ns versus 4 ns). While the higher current capacity is not detrimental, the slower recovery time may affect circuit performance in high-frequency switching applications. This part is suitable only when higher current capacity is required.

Q: Are there RoHS3 compliant alternatives available?

A: Yes. The 1N4454-TAP, 1N4454-TR, 1N4454 TR PBFREE, 1N4148-G, 1N4148-T26A, and 1N4148-T50R are all ROHS3 compliant. The original 1N4148 is RoHS non-compliant. For applications requiring RoHS3 compliance, any of these alternatives are suitable based on your specific electrical and packaging requirements.

Q: Can I use the 1N4148-T26A or 1N4148-T50A in place of the 1N4148?

A: Yes, with design margin consideration. Both parts have a higher reverse voltage rating (100 V versus 75 V) and higher current capacity (200 mA versus 150 mA). All other critical parameters match the original specification. These parts are suitable for applications where higher voltage and current margins are acceptable or beneficial.

Q: What is the difference between the 1N4454 TR PBFREE and the 1N4454-TAP?

A: The 1N4454 TR PBFREE is supplied in Cut Tape packaging and has a maximum junction temperature of 200°C. The 1N4454-TAP is supplied in Tape & Box packaging and has a maximum junction temperature of 175°C. Both parts meet all electrical specifications of the original 1N4148. Selection depends on your assembly process and thermal requirements.

Q: Why is the 1N4448 not recommended?

A: The 1N4448 is discontinued at DiGi Electronics and has a reduced maximum junction temperature of 150°C compared to the original 175°C. While the electrical specifications are similar, the discontinued status and reduced thermal rating make it unsuitable for new designs. The 1N4454 series is the preferred alternative.

Q: Can the 1N4148-1 be used as a substitute?

A: The 1N4148-1 is not recommended. Although it has the same voltage rating (75 V), it exhibits significantly degraded performance: reverse recovery time is 20 ns (versus 4 ns) and reverse leakage current is 500 nA (versus 5 µA). These parameters make it unsuitable for applications requiring fast switching or low leakage characteristics.

Q: What packaging options are available for the recommended substitutes?

A: The 1N4454-TAP is supplied in Tape & Box format, and the 1N4454-TR is supplied in Tape & Reel format. Both are through-hole DO-35 packages. The 1N4454 TR PBFREE is supplied in Cut Tape format. Selection depends on your assembly equipment and process requirements.

Q: Are all recommended substitutes available in high volume?

A: The 1N4454-TAP has 892 pieces in stock, the 1N4454-TR has 1,093 pieces in stock, and the 1N4454 TR PBFREE has 31,494 pieces in stock. The enhanced substitutes 1N4148-T50R and 1N4148-T26A have 39,503 and 248,250 pieces in stock respectively. Inventory levels should be verified with your supplier for current availability.

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