1N4448 BK Equivalent & Substitute Parts

Part Overview

The 1N4448 BK is a general-purpose small signal diode manufactured by Central Semiconductor Corp, rated for 100 V DC reverse voltage and 150 mA average rectified current in a DO-35 through-hole package. This part is classified as obsolete, which necessitates identification of active equivalent and substitute components for ongoing design and procurement requirements. Equivalent parts maintain identical electrical and mechanical specifications, while substitute parts provide functional alternatives within acceptable parameter ranges for the DO-35 diode category.

Key Parameters

Parameter	Value	Unit
Voltage - DC Reverse (Vr) (Max)	100	V
Current - Average Rectified (Io)	150	mA
Voltage - Forward (Vf) (Max) @ If	720 mV @ 5 mA	mV @ mA
Reverse Recovery Time (trr)	4	ns
Current - Reverse Leakage @ Vr	25	nA @ 20 V
Capacitance @ Vr, F	4	pF @ 0V, 1MHz
Mounting Type	Through Hole	-
Package / Case	DO-204AH, DO-35, Axial	-
Operating Temperature - Junction	-65 to 200	°C
Technology	Standard	-
Speed Classification	Small Signal ≤ 200mA (Io), Any Speed	-

Substitute Part Grouping Explanation

Substitution logic for the 1N4448 BK is based on the following critical parameters that define functional compatibility within the DO-35 small signal diode category:

Primary Substitution Criteria:

Voltage - DC Reverse (Vr) (Max): Must equal or exceed 100 V
Package / Case: Must be DO-204AH, DO-35, or Axial equivalent
Mounting Type: Must be Through Hole
Speed Classification: Must support Small Signal ≤ 200mA (Io) or higher current classifications
Technology: Standard diode technology

Secondary Compatibility Parameters:

Current - Average Rectified (Io): 150 mA baseline; parts rated 150 mA, 200 mA, or 300 mA are acceptable
Reverse Recovery Time (trr): 4 ns or 8 ns acceptable
Operating Temperature Range: Must support minimum -55°C to 175°C or broader range
RoHS Status: Active parts must be ROHS3 Compliant

Parts are grouped into two categories: Direct Equivalents (matching 150 mA current rating) and Functional Substitutes (higher current ratings with compatible electrical characteristics).

Parameter Comparison

Part Number	Manufacturer	Vr (Max) V	Io mA	Vf (Max) @ If	trr ns	Ir @ Vr	Package	Status	RoHS
1N4448 BK	Central Semiconductor Corp	100	150	720 mV @ 5 mA	4	25 nA @ 20 V	DO-35	Obsolete	Request verification
1N4448 A0G	Taiwan Semiconductor Corporation	100	150	720 mV @ 5 mA	4	5 µA @ 75 V	DO-35	Active	ROHS3 Compliant
1N4448TR	Vishay General Semiconductor - Diodes Division	100	150	1 V @ 100 mA	8	5 µA @ 75 V	DO-35	Active	ROHS3 Compliant
1N914B A0G	Taiwan Semiconductor Corporation	100	150	720 mV @ 5 mA	4	5 µA @ 75 V	DO-35	Active	ROHS3 Compliant
1N4148-T26A	onsemi	100	200	1 V @ 10 mA	4	5 µA @ 75 V	DO-35	Active	ROHS3 Compliant
1N4148TR	Fairchild Semiconductor	100	200	1 V @ 10 mA	4	5 µA @ 75 V	DO-35	Active	ROHS3 Compliant
1N914TAP	Vishay General Semiconductor - Diodes Division	100	300	1 V @ 10 mA	4	5 µA @ 75 V	DO-35	Active	ROHS3 Compliant
1N914TR	Fairchild Semiconductor	100	200	1 V @ 10 mA	4	5 µA @ 75 V	DO-35	Active	ROHS3 Compliant

Engineering Selection Recommendations

Direct Equivalents (150 mA Rating):

The 1N4448 A0G (Taiwan Semiconductor Corporation) and 1N914B A0G (Taiwan Semiconductor Corporation) are direct electrical equivalents with identical 150 mA current ratings and matching forward voltage characteristics (720 mV @ 5 mA). Both parts are active, ROHS3 compliant, and available in high inventory quantities (1119 and 812 units respectively). These parts are recommended as primary replacements for the obsolete 1N4448 BK.

The 1N4448TR (Vishay General Semiconductor - Diodes Division) maintains the 150 mA current rating and DO-35 package but specifies forward voltage at 1 V @ 100 mA and reverse recovery time of 8 ns. This part is active and ROHS3 compliant with 19,900 units in inventory.

Functional Substitutes (200 mA Rating):

The 1N4148-T26A (onsemi) and 1N4148TR (Fairchild Semiconductor) are rated for 200 mA average rectified current, exceeding the 150 mA baseline. Both maintain 100 V reverse voltage rating, DO-35 package, and 4 ns reverse recovery time. These parts are active and ROHS3 compliant with substantial inventory availability (248,250 and 240,400 units respectively). Selection of 200 mA rated parts provides design margin for applications requiring higher current capacity within the same package footprint.

The 1N914TR (Fairchild Semiconductor) provides 200 mA rating with identical electrical characteristics to the 1N4148 series, offering an alternative source from the same manufacturer.

Higher Current Substitute (300 mA Rating):

The 1N914TAP (Vishay General Semiconductor - Diodes Division) is rated for 300 mA average rectified current in the DO-35 package. This part includes AEC-Q101 automotive qualification and is classified as Fast Recovery ≤ 500ns, > 200mA (Io). With 63,368 units in inventory, this part is suitable for applications requiring maximum current capacity within the DO-35 form factor.

Compliance and Availability:

All recommended substitute parts are ROHS3 compliant and REACH unaffected. All parts share ECCN EAR99 and HTSUS 8541.10.0070 classifications with the original 1N4448 BK. Selection should prioritize active parts with confirmed inventory status and compliance certifications appropriate to the end application.

Frequently Asked Questions (FAQ)

Q: Can the 1N4148-T26A replace the 1N4448 BK in all applications?

A: The 1N4148-T26A is electrically compatible based on 100 V reverse voltage rating, DO-35 package, and small signal diode classification. The 200 mA current rating exceeds the 150 mA baseline, providing design margin. Forward voltage specification differs (1 V @ 10 mA versus 720 mV @ 5 mA), which may affect circuit performance in precision applications. Verify forward voltage requirements in the specific circuit design before substitution.

Q: What is the difference between 1N4448 A0G and 1N914B A0G?

A: Both parts are rated 100 V, 150 mA, with identical forward voltage (720 mV @ 5 mA) and reverse recovery time (4 ns). The primary difference is the base product number designation: 1N4448 versus 1N914. Both are manufactured by Taiwan Semiconductor Corporation, are ROHS3 compliant, and are functionally equivalent for DO-35 applications. Selection between these parts may be based on design documentation requirements or supplier availability.

Q: Why would I select the 1N914TAP (300 mA) over the 1N4448 A0G (150 mA)?

A: The 1N914TAP provides higher current capacity (300 mA) in the same DO-35 package, offering design margin for applications with variable or peak current demands. The 1N914TAP is classified as Fast Recovery with AEC-Q101 automotive qualification, making it suitable for automotive or high-reliability applications. Selection depends on circuit current requirements and qualification standards applicable to the end product.

Q: Are all substitute parts available in the same packaging options?

A: All recommended substitute parts are available in DO-35 through-hole package. Packaging variants differ: 1N4448 A0G is available in Tape & Box (TB), 1N4148-T26A in Cut Tape (CT), 1N4448TR in Cut Tape (CT), and 1N914TAP in Cut Tape (CT). Verify packaging requirements for assembly processes before final part selection.

Q: What is the operating temperature range consideration for substitution?

A: The original 1N4448 BK specifies -65°C to 200°C junction temperature. Substitute parts specify narrower ranges: 1N4448 A0G (-65°C to 150°C), 1N4148-T26A (-55°C to 175°C), 1N4148TR (-65°C to 175°C), and 1N914TAP (-65°C to 175°C). For applications requiring operation above 175°C, verify that the selected substitute part's maximum junction temperature meets system requirements.

Q: Can I use these parts interchangeably in existing PCB designs?

A: All recommended parts share DO-35 axial package dimensions and through-hole mounting, ensuring mechanical compatibility with existing PCB layouts. Electrical interchangeability depends on circuit-specific requirements for forward voltage, reverse recovery time, and current capacity. Conduct circuit simulation or prototype testing to confirm functional equivalence before production implementation.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message