6N139SD Optoisolator Equivalent & Substitute Parts

Part Overview

The 6N139SD is an optoisolator with Darlington output and base connection, manufactured by onsemi. It provides 2500Vrms isolation with 1 channel in an 8-SMD gull wing package. The device is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility across isolation voltage, output type, channel configuration, and thermal operating range.

Key Parameters

Parameter	Value
Manufacturer Part Number	6N139SD
Manufacturer	onsemi
Category	Optoisolators
Number of Channels	1
Voltage - Isolation	2500Vrms
Current Transfer Ratio (Min)	500% @ 1.6mA
Output Type	Darlington with Base
Voltage - Output (Max)	18V
Current - Output / Channel	60mA
Operating Temperature	-40°C ~ 85°C
Package / Case	8-SMD, Gull Wing
Mounting Type	Surface Mount
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution for the 6N139SD is determined by the following critical parameters:

Output Type: Darlington with Base (required for pin-compatible replacement)
Number of Channels: 1 channel (functional requirement)
Voltage - Isolation: Minimum 2500Vrms (equal or higher isolation acceptable)
Voltage - Output (Max): 18V (maximum output voltage capability)
Current - Output / Channel: 60mA (output current capability)
Package / Case: 8-SMD, Gull Wing (physical and electrical compatibility)
Mounting Type: Surface Mount (assembly compatibility)

Substitute parts are grouped into two categories:

Direct Manufacturer Equivalent: 6N139SDM (onsemi) — same base product family with enhanced isolation rating (5000Vrms) and improved thermal range (-40°C ~ 100°C), available in Tape & Reel packaging.

Cross-Manufacturer Alternatives: HCPL-4701 series (Broadcom Limited) — functionally equivalent Darlington optoisolators with isolation ratings from 3750Vrms to 5000Vrms, available in multiple packaging and Current Transfer Ratio configurations.

Parameter Comparison

Parameter	6N139SD	6N139SDM	HCPL-4701#300	HCPL-4701-300E	HCPL-4701-320E	HCPL-4701-360E	HCPL-4701-500E	HCPL-4701-520E	HCPL-4701-560E
Manufacturer	onsemi	onsemi	Broadcom Limited	Broadcom Limited	Broadcom Limited	Broadcom Limited	Broadcom Limited	Broadcom Limited	Broadcom Limited
Number of Channels	1	1	1	1	1	1	1	1	1
Voltage - Isolation	2500Vrms	5000Vrms	3750Vrms	3750Vrms	5000Vrms	3750Vrms	3750Vrms	5000Vrms	3750Vrms
Current Transfer Ratio (Min)	500% @ 1.6mA	500% @ 1.6mA	600% @ 500µA	600% @ 500µA	600% @ 500µA	600% @ 500µA	600% @ 500µA	600% @ 500µA	600% @ 500µA
Current Transfer Ratio (Max)	—	—	8000% @ 500µA	8000% @ 500µA	8000% @ 500µA	8000% @ 500µA	8000% @ 500µA	8000% @ 500µA	8000% @ 500µA
Turn On / Turn Off Time (Typ)	1.5µs, 7µs	240ns, 1.3µs	3µs, 34µs	3µs, 34µs	3µs, 34µs	3µs, 34µs	3µs, 34µs	3µs, 34µs	3µs, 34µs
Output Type	Darlington with Base	Darlington with Base	Darlington with Base	Darlington with Base	Darlington with Base	Darlington with Base	Darlington with Base	Darlington with Base	Darlington with Base
Voltage - Output (Max)	18V	18V	18V	18V	18V	18V	18V	18V	18V
Current - Output / Channel	60mA	60mA	60mA	60mA	60mA	60mA	60mA	60mA	60mA
Voltage - Forward (Vf) (Typ)	1.3V	1.3V	1.25V	1.25V	1.25V	1.25V	1.25V	1.25V	1.25V
Current - DC Forward (If) (Max)	20mA	20mA	10mA	10mA	10mA	10mA	10mA	10mA	10mA
Operating Temperature	-40°C ~ 85°C	-40°C ~ 100°C	0°C ~ 70°C	0°C ~ 70°C	0°C ~ 70°C	0°C ~ 70°C	0°C ~ 70°C	0°C ~ 70°C	0°C ~ 70°C
Package / Case	8-SMD, Gull Wing	8-SMD, Gull Wing	8-SMD, Gull Wing	8-SMD, Gull Wing	8-SMD, Gull Wing	8-SMD, Gull Wing	8-SMD, Gull Wing	8-SMD, Gull Wing	8-SMD, Gull Wing
Mounting Type	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount
Product Status	Obsolete	Active	Active	Active	Active	Active	Active	Active	Active
RoHS Status	—	ROHS3 Compliant	RoHS non-compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Packaging	—	Tape & Reel (TR)	Tube	Tube	Tube	Tube	Tape & Reel (TR)	Tape & Reel (TR)	Tape & Reel (TR)

Engineering Selection Recommendations

6N139SDM (onsemi) is the primary direct equivalent. It maintains the same base product family, output configuration, and package format. The 6N139SDM offers enhanced isolation (5000Vrms vs. 2500Vrms) and extended operating temperature range (-40°C ~ 100°C vs. -40°C ~ 85°C). It is ROHS3 compliant and available in active production status with Tape & Reel packaging suitable for automated assembly.

HCPL-4701 series (Broadcom Limited) provides cross-manufacturer alternatives with functional equivalence. Selection within this series depends on isolation voltage requirement and operating temperature constraints:

HCPL-4701-320E and HCPL-4701-520E offer 5000Vrms isolation matching the enhanced 6N139SDM specification.
HCPL-4701-300E, HCPL-4701-360E, and HCPL-4701-560E provide 3750Vrms isolation, suitable for applications requiring minimum 2500Vrms.
HCPL-4701-500E offers 3750Vrms isolation in Tape & Reel packaging.

All HCPL-4701 variants are ROHS3 compliant and in active production. Operating temperature range is limited to 0°C ~ 70°C, which is narrower than the 6N139SD specification. Applications requiring operation below 0°C or above 70°C must use 6N139SDM.

The HCPL-4701 series exhibits higher Current Transfer Ratio (600% minimum, up to 8000% maximum) compared to the 6N139SD (500% minimum), providing improved switching characteristics and faster response times (3µs turn-on vs. 1.5µs, 34µs turn-off vs. 7µs).

Frequently Asked Questions (FAQ)

Q: Can 6N139SDM directly replace 6N139SD in existing designs?

A: Yes. The 6N139SDM maintains identical pin configuration, output type (Darlington with Base), package format (8-SMD gull wing), and electrical ratings. The enhanced isolation voltage (5000Vrms) and extended temperature range provide improved performance margins. No circuit modifications are required.

Q: What are the key differences between 6N139SDM and HCPL-4701 series?

A: Both are functionally equivalent Darlington optoisolators with identical output voltage (18V max) and current (60mA) ratings. Primary differences are: (1) Operating temperature range — 6N139SDM supports -40°C ~ 100°C while HCPL-4701 series is limited to 0°C ~ 70°C; (2) Current Transfer Ratio — HCPL-4701 series specifies both minimum (600%) and maximum (8000%) values, while 6N139SD/6N139SDM specify minimum only (500%); (3) Switching speed — HCPL-4701 series exhibits slower response (3µs turn-on, 34µs turn-off) compared to 6N139SDM (240ns turn-on, 1.3µs turn-off).

Q: Which substitute part is suitable for low-temperature applications below 0°C?

A: Only 6N139SDM supports operation at temperatures below 0°C, with a minimum rating of -40°C. All HCPL-4701 variants are rated 0°C ~ 70°C and are not suitable for sub-zero environments.

Q: Are all substitute parts ROHS3 compliant?

A: 6N139SDM and all HCPL-4701 variants except HCPL-4701#300 are ROHS3 compliant. HCPL-4701#300 is RoHS non-compliant and should not be used in applications requiring RoHS certification.

Q: What packaging options are available for production quantities?

A: 6N139SDM is available in Tape & Reel (TR) packaging. Within the HCPL-4701 series, HCPL-4701-500E, HCPL-4701-520E, and HCPL-4701-560E are supplied in Tape & Reel. HCPL-4701#300, HCPL-4701-300E, HCPL-4701-320E, and HCPL-4701-360E are supplied in Tube packaging.

Q: Can HCPL-4701 series be used in applications requiring 2500Vrms isolation?

A: Yes. HCPL-4701 variants rated 3750Vrms or 5000Vrms exceed the 2500Vrms requirement and are electrically compatible. However, applications requiring operation below 0°C must use 6N139SDM, as HCPL-4701 series minimum operating temperature is 0°C.

Q: What is the impact of higher Current Transfer Ratio in HCPL-4701 series?

A: Higher Current Transfer Ratio (600% minimum vs. 500% minimum) indicates improved optical coupling efficiency and faster switching response. This results in reduced input current requirements and faster turn-on time (3µs vs. 1.5µs for 6N139SD). Applications with tight timing constraints may benefit from this characteristic.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message