6N138-V Optoisolator Equivalent & Substitute Parts

Part Overview

The 6N138-V is an optoisolator with Darlington output and integrated base resistor, manufactured by Everlight Electronics Co Ltd. This component provides 5000Vrms isolation between input and output circuits in a single-channel configuration. The part is currently in active production status with 1101 pieces available in inventory.

Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained across critical parameters including isolation voltage, current transfer ratio, output type, package configuration, and operating temperature range. The 6N138-V has documented substitutes within the optoisolator category that maintain functional equivalence.

Substiute Parts

6N138-V

Everlight Electronics Co LtdIn Stock: 11186N138-V Datasheet

Current PartRFQ

6N138

Fairchild SemiconductorIn Stock: 121646N138 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 6N138-V is determined by strict equivalence across the following critical parameters:

Isolation Voltage: 5000Vrms minimum required Number of Channels: 1 channel only Output Configuration: Darlington with Base output type Package Type: 8-DIP (0.300", 7.62mm) through-hole mounting Current Transfer Ratio: Minimum 300% @ 1.6mA Maximum Output Current: 60mA per channel Input Type: DC input Maximum Output Voltage: 7V

Substitute parts must maintain all of these parameters within the specified tolerances. Deviations in isolation voltage, channel count, output type, or package configuration disqualify a part from substitution consideration.

Parameter Comparison

Engineering Selection Recommendations

Primary Selection: 6N138-V (Everlight Electronics)

The 6N138-V is the recommended primary choice for new designs and production applications. This part maintains active product status with confirmed inventory availability of 1101 pieces. The component is ROHS3 compliant, meeting current environmental and regulatory requirements for commercial and industrial applications.

Substitute Selection: 6N138 (Fairchild Semiconductor)

The 6N138 from Fairchild Semiconductor is electrically equivalent to the 6N138-V across all critical isolation, switching, and output parameters. However, this part carries obsolete product status and is non-compliant with RoHS standards. The Fairchild 6N138 is suitable only for legacy system maintenance, repair, or applications where RoHS compliance is not required. The extended operating temperature range (-55°C ~ 100°C) compared to the 6N138-V (-40°C ~ 85°C) provides additional thermal margin in specific applications, though this does not override the obsolescence and compliance limitations.

Compliance Consideration: Applications subject to RoHS regulations, environmental directives, or procurement policies requiring active product status must use the 6N138-V. The Fairchild 6N138 is restricted to non-compliant applications only.

Frequently Asked Questions (FAQ)

Q: Can the 6N138 (Fairchild) be used as a direct replacement for the 6N138-V (Everlight)?

A: Electrical substitution is valid. Both parts share identical isolation voltage (5000Vrms), current transfer ratio (300% @ 1.6mA), output type (Darlington with Base), package configuration (8-DIP), and output current rating (60mA). However, the Fairchild part is obsolete and RoHS non-compliant. Substitution is restricted to applications where these limitations are acceptable.

Q: What are the key parameters that determine substitution eligibility?

A: Substitution requires equivalence in: isolation voltage (5000Vrms), number of channels (1), output type (Darlington with Base), package type (8-DIP through-hole), current transfer ratio (minimum 300% @ 1.6mA), maximum output current (60mA), input type (DC), and maximum output voltage (7V). Deviation in any of these parameters disqualifies substitution.

Q: Are there differences in switching speed between the 6N138-V and 6N138?

A: Minor differences exist. The 6N138-V has turn-on/turn-off times of 1.4µs and 8µs respectively, while the Fairchild 6N138 specifies 1.35µs and 7.6µs. These differences are within typical application tolerances for optoisolator circuits and do not affect functional compatibility.

Q: What is the operating temperature difference between these parts?

A: The 6N138-V operates from -40°C to 85°C, while the Fairchild 6N138 operates from -55°C to 100°C. The Fairchild part provides extended low-temperature and high-temperature capability. However, this advantage is offset by obsolescence and RoHS non-compliance status.

Q: Can these parts be used interchangeably in PCB designs?

A: Yes, from a mechanical and electrical standpoint. Both parts use identical 8-DIP (0.300", 7.62mm) through-hole packaging with the same pin configuration and functional output characteristics. PCB layouts designed for one part accommodate the other without modification.

Q: Why is RoHS compliance important for part selection?

A: RoHS3 compliance indicates the part meets current environmental regulations restricting hazardous substances in electrical and electronic equipment. The 6N138-V's compliance status makes it suitable for applications subject to regulatory requirements, export restrictions, or corporate procurement policies. The Fairchild 6N138's non-compliance restricts its use to legacy or non-regulated applications.

Q: Is the 6N138 still available for purchase?

A: The Fairchild 6N138 carries obsolete product status, indicating discontinued production. While inventory may exist through secondary distributors, availability is limited and declining. The 6N138-V from Everlight is the recommended choice for assured supply and long-term availability.