1N5240B-TP Zener Diode Equivalent & Substitute Parts

Part Overview

The 1N5240B-TP is a 10 V, 500 mW Zener diode manufactured by Micro Commercial Co in a DO-35 through-hole axial package. This component is classified as obsolete, though 884 pieces remain in stock as new original inventory. The part is ROHS3 compliant and suitable for voltage regulation and protection applications requiring nominal Zener voltage of 10 V with ±5% tolerance.

Due to the obsolete product status, equivalent and substitute parts from active manufacturers are necessary for ongoing design support, production continuity, and long-term component availability. Substitute parts maintain the core electrical specifications while offering improved availability and extended product lifecycles.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nom)	10	V
Tolerance	±5	%
Power - Max	500	mW
Impedance (Max)	17	Ohms
Current - Reverse Leakage @ Vr	3	µA @ 8 V
Voltage - Forward (Vf) (Max) @ If	1.1	V @ 200 mA
Operating Temperature	-55 to 150	°C
Mounting Type	Through Hole
Package / Case	DO-35 (DO-204AH)

Substitute Part Grouping Explanation

Substitution of the 1N5240B-TP is determined by the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

Voltage - Zener (Nom): 10 V (exact match required)
Tolerance: ±5% (exact match required)
Mounting Type: Through Hole (required for mechanical compatibility)
Package / Case: DO-35 or equivalent axial package (required for PCB fit)

Secondary Compatibility Parameters:

Power - Max: 500 mW or greater (equal or higher rating acceptable)
Impedance (Max): 17 Ohms or lower (lower impedance acceptable)
Current - Reverse Leakage: 3 µA @ 8 V or lower (lower leakage acceptable)
Operating Temperature Range: Must encompass or exceed -55°C to 150°C

Substitute parts are grouped into two categories:

Category A - Direct Equivalents (DO-35 Package, 500 mW): Parts maintaining identical power rating and package form factor. These include 1N5240B, 1N5240BTR, 1N961B-1, and BZX79C10.

Category B - Higher Power Alternatives (DO-41 Package, 1 W or Greater): Parts with increased power dissipation capability in larger packages. These include 1N4740A and 1N4740ATR. The 1N5067 represents a 3 W alternative for applications requiring enhanced thermal performance.

Parameter Comparison

Part Number	Manufacturer	Vz (Nom)	Tolerance	Power Max	Zzt (Max)	Ir @ Vr	Vf (Max) @ If	Temp Range	Package	Status
1N5240B-TP	Micro Commercial Co	10 V	±5%	500 mW	17 Ω	3 µA @ 8 V	1.1 V @ 200 mA	-55 to 150°C	DO-35	Obsolete
1N5240B	Microchip Technology	10 V	±5%	500 mW	17 Ω	3 µA @ 8 V	1.5 V @ 200 mA	-65 to 175°C	DO-35	Active
1N5240BTR	Fairchild Semiconductor	10 V	±5%	500 mW	17 Ω	3 µA @ 8 V	1.2 V @ 200 mA	-65 to 200°C	DO-35	Active
1N961B-1	Microchip Technology	10 V	±5%	500 mW	8.5 Ω	10 µA @ 7.6 V	1.1 V @ 200 mA	-65 to 175°C	DO-35	Active
BZX79C10	Taiwan Semiconductor Corporation	10 V	±5%	500 mW	20 Ω	200 nA @ 7 V	1.5 V @ 100 mA	-65 to 175°C	DO-35	Active
1N4740A	Lumimax Optoelectronic Technology	10 V	±5%	1 W	7 Ω	10 µA @ 7.6 V	1.2 V @ 200 mA	-65 to 200°C	DO-41	Active
1N4740ATR	onsemi	10 V	±5%	1 W	7 Ω	10 µA @ 7.6 V	Not specified	-65 to 200°C	DO-41	Active
1N5067	Microchip Technology	10 V	±5%	3 W	4 Ω	40 µA @ 7.6 V	Not specified	-65 to 175°C	Axial	Active

Engineering Selection Recommendations

For Direct Replacement (DO-35 Package, 500 mW Rating):

The 1N5240B from Microchip Technology is the primary direct equivalent. It maintains identical electrical specifications, operates across an extended temperature range (-65 to 175°C), and holds active product status with RoHS compliance. This part is suitable for applications where the original 1N5240B-TP specifications are required without modification.

The 1N5240BTR from Fairchild Semiconductor provides an alternative direct equivalent with extended upper operating temperature limit (200°C) and active product status. This part is appropriate for applications requiring enhanced thermal margin.

The 1N961B-1 from Microchip Technology offers improved impedance characteristics (8.5 Ω versus 17 Ω) while maintaining 500 mW power rating and DO-35 package. This part is suitable for applications where lower dynamic impedance is beneficial.

The BZX79C10 from Taiwan Semiconductor Corporation provides ROHS3 compliance with exceptionally low reverse leakage current (200 nA @ 7 V). This part is appropriate for precision voltage reference applications requiring minimal leakage.

For Higher Power Applications (1 W Rating):

The 1N4740A from Lumimax Optoelectronic Technology and 1N4740ATR from onsemi both provide 1 W power dissipation in DO-41 package. These parts are suitable for applications requiring increased thermal capacity beyond 500 mW. PCB layout modification is required to accommodate the larger DO-41 package footprint.

For Maximum Power Dissipation (3 W Rating):

The 1N5067 from Microchip Technology provides 3 W power rating with superior impedance characteristics (4 Ω). This part is suitable for high-current voltage regulation applications. Axial package configuration requires PCB layout accommodation.

Compliance Considerations:

All substitute parts maintain REACH Unaffected status and EAR99 classification. RoHS compliance varies: 1N5240B is RoHS non-compliant, while 1N5240BTR, BZX79C10, and 1N4740A hold RoHS or ROHS3 compliance. Selection should account for end-product RoHS requirements.

Frequently Asked Questions (FAQ)

Q: Can the 1N5240B-TP be directly replaced with 1N5240B?

A: Yes. The 1N5240B from Microchip Technology maintains identical nominal Zener voltage (10 V), tolerance (±5%), power rating (500 mW), impedance (17 Ω), and package (DO-35). The primary difference is extended operating temperature range (-65 to 175°C versus -55 to 150°C) and active product status. Direct PCB substitution is possible without layout modification.

Q: What is the difference between DO-35 and DO-41 packages?

A: DO-35 and DO-41 are both axial through-hole packages for diodes. DO-35 is the smaller package used in the original 1N5240B-TP and direct equivalents. DO-41 is a larger package used in 1 W rated parts (1N4740A, 1N4740ATR). PCB footprint modification is required when substituting between these packages. DO-41 provides improved thermal dissipation due to larger physical dimensions.

Q: Can I use a 1 W Zener diode (1N4740A) in place of a 500 mW part (1N5240B-TP)?

A: Yes, provided PCB layout accommodates the larger DO-41 package. The 1N4740A maintains identical Zener voltage (10 V) and tolerance (±5%). The higher power rating (1 W versus 500 mW) and lower impedance (7 Ω versus 17 Ω) provide improved thermal performance and dynamic characteristics. This substitution is appropriate for applications where the original 500 mW rating is marginal or where enhanced reliability is required.

Q: What are the implications of different impedance values?

A: Impedance (Zzt) affects dynamic voltage regulation performance. Lower impedance values provide better voltage stability under changing load conditions. The 1N961B-1 (8.5 Ω) and 1N4740A (7 Ω) offer superior dynamic performance compared to the original 1N5240B-TP (17 Ω). The BZX79C10 (20 Ω) exhibits slightly higher impedance. Selection depends on circuit requirements for voltage regulation accuracy.

Q: Are there RoHS compliance differences between substitute parts?

A: Yes. The original 1N5240B-TP is ROHS3 compliant. The 1N5240B from Microchip is RoHS non-compliant. The 1N5240BTR, BZX79C10, and 1N4740A are RoHS or ROHS3 compliant. End-product RoHS requirements must be verified before final part selection.

Q: What is the significance of reverse leakage current differences?

A: Reverse leakage current affects circuit performance in precision applications. The BZX79C10 exhibits exceptionally low leakage (200 nA @ 7 V), while the original 1N5240B-TP specifies 3 µA @ 8 V. Lower leakage is beneficial in high-impedance circuits and precision voltage reference applications. Higher leakage has minimal impact in standard voltage regulation circuits.

Q: Can I substitute parts with different operating temperature ranges?

A: Yes, provided the substitute part's temperature range encompasses the application requirements. The original 1N5240B-TP operates from -55 to 150°C. All substitute parts extend this range to at least -65 to 175°C, providing improved margin for extreme environment applications. Verify that the substitute part's temperature range meets or exceeds application specifications.

Q: What packaging options are available for 10 V, 500 mW Zener diodes?

A: The 10 V, 500 mW rating is available in DO-35 (DO-204AH) axial package only. This includes 1N5240B, 1N5240BTR, 1N961B-1, and BZX79C10. Higher power ratings (1 W and 3 W) are available in larger packages (DO-41 and Axial) to accommodate increased thermal dissipation requirements.

Q: How do I determine which substitute part is appropriate for my application?

A: Identify the critical parameters: required Zener voltage (10 V for this family), tolerance (±5%), minimum power dissipation requirement, operating temperature range, and PCB package constraints. For direct replacement without layout modification, select from DO-35 package alternatives (1N5240B, 1N5240BTR, 1N961B-1, BZX79C10). For applications requiring enhanced thermal performance or lower impedance, consider 1 W alternatives (1N4740A, 1N4740ATR). Verify RoHS compliance requirements before final selection.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message