4N25 Optoisolator Transistor Equivalent & Substitute Parts

Part Overview

The 4N25 is a single-channel optoisolator with transistor output and base connection, designed for DC input applications requiring galvanic isolation. This component is classified as Active and maintains full production status. The 4N25 series provides isolation voltage of 7.5Vpk with a current transfer ratio minimum of 20% at 10mA input. Finding equivalent or substitute parts becomes necessary when addressing specific application requirements such as higher isolation voltage ratings, increased output current capacity, or alternative packaging and delivery formats while maintaining functional compatibility within the 6-DIP form factor.

Substiute Parts

4N25

Isocom Components 2004 LTDIn Stock: 384994N25 Datasheet

Current PartRFQ

4N25-000E

Broadcom LimitedIn Stock: 30614N25-000E Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 4N25 optoisolator is determined by strict alignment of the following critical parameters:

Mandatory Compatibility Parameters:

• Single-channel configuration (Number of Channels = 1)
• Transistor output with base connection (Output Type)
• DC input type
• 6-DIP through-hole package format (0.300", 7.62mm)
• Operating temperature range: -55°C to 100°C
• Current transfer ratio minimum of 20% @ 10mA
• Maximum output voltage of 30V
• Vce saturation maximum of 500mV

Allowable Variation Parameters:

• Isolation voltage: The 4N25 operates at 7.5Vpk. Substitute parts may feature higher isolation ratings (such as 2500Vrms) while maintaining all other electrical and mechanical specifications.
• Output current capacity: The 4N25 supports 50mA per channel. Substitute parts may provide equal or greater output current ratings.
• Rise/Fall time: Variations in switching speed (2µs for 4N25 versus 3µs for alternatives) are acceptable provided output switching characteristics remain within application requirements.
• Forward current maximum: The 4N25 specifies 60mA maximum DC forward current. Substitutes may accommodate higher forward current ratings.

The 4N25-000E variant meets all mandatory compatibility criteria while offering enhanced isolation voltage (2500Vrms) and increased output current capacity (100mA), making it a direct functional substitute within the same package footprint.

Parameter Comparison

Engineering Selection Recommendations

Both the 4N25 and 4N25-000E maintain Active product status and full ROHS3 compliance, ensuring continued availability and regulatory alignment for new designs. The 4N25-000E variant is suitable for applications requiring enhanced galvanic isolation (2500Vrms versus 7.5Vpk) and higher output current capacity (100mA versus 50mA per channel). The identical package footprint (6-DIP through-hole) and matching operating temperature range (-55°C to 100°C) enable direct board-level substitution without layout modification. Selection between these parts depends on isolation voltage requirements and maximum output current demands of the target application. Both components maintain identical current transfer ratio specifications (20% minimum @ 10mA) and output voltage ratings (30V maximum), ensuring functional equivalence in DC input optoisolation circuits.

Frequently Asked Questions (FAQ)

Q: Can the 4N25-000E replace the 4N25 in existing designs?

A: Yes. The 4N25-000E is a direct substitute for the 4N25 in the same 6-DIP through-hole package. Both components share identical pin configurations, operating temperature ranges, and core electrical characteristics including current transfer ratio and output voltage ratings. The 4N25-000E provides higher isolation voltage (2500Vrms) and increased output current capacity (100mA), making it functionally compatible and superior in these specifications.

Q: What are the key differences between 4N25 and 4N25-000E?

A: The primary differences are isolation voltage rating (7.5Vpk for 4N25 versus 2500Vrms for 4N25-000E), output current capacity (50mA versus 100mA), maximum DC forward current (60mA versus 80mA), and rise/fall time (2µs versus 3µs). All other parameters including package format, pin count, operating temperature, and current transfer ratio remain identical.

Q: Are both parts suitable for high-isolation applications?

A: The 4N25 provides 7.5Vpk isolation, suitable for standard signal isolation. The 4N25-000E provides 2500Vrms isolation, appropriate for applications requiring enhanced galvanic separation between circuits. Selection depends on the specific isolation voltage requirement of the application.

Q: Do these parts require different PCB layouts?

A: No. Both the 4N25 and 4N25-000E use identical 6-DIP (0.300", 7.62mm) through-hole packages with matching pin assignments. PCB layouts designed for the 4N25 accommodate the 4N25-000E without modification.

Q: What is the current transfer ratio specification for both parts?

A: Both the 4N25 and 4N25-000E specify a minimum current transfer ratio of 20% at 10mA input current. This parameter is identical across both variants.

Q: Are both parts RoHS compliant?

A: Yes. Both the 4N25 and 4N25-000E are ROHS3 compliant and maintain Active product status, ensuring regulatory compliance and continued manufacturing availability.