EL817 Optoisolator Equivalent & Substitute Parts

Part Overview

The EL817 is a single-channel optoisolator with transistor output manufactured by Everlight Electronics Co Ltd. This component provides 5000Vrms isolation voltage and is designed for DC input applications requiring galvanic isolation in 4-DIP through-hole packages. The part is active in production with 55,300 units in current inventory stock.

Substitute parts are identified when equivalent electrical performance and mechanical compatibility are maintained across the critical isolation voltage, output type, channel configuration, and package form factor specifications.

Substiute Parts

EL817

Everlight Electronics Co LtdIn Stock: 55354EL817 Datasheet

Current PartRFQ

FOD817300

Fairchild SemiconductorIn Stock: 12647FOD817300 Datasheet

SimilarRFQ

FOD817A300

onsemiIn Stock: 56401FOD817A300 Datasheet

SimilarRFQ

FOD817B300

onsemiIn Stock: 35175FOD817B300 Datasheet

SimilarRFQ

FOD817C300

onsemiIn Stock: 32138FOD817C300 Datasheet

SimilarRFQ

FOD817D300

Fairchild SemiconductorIn Stock: 8685FOD817D300 Datasheet

SimilarRFQ

140817140010

Würth ElektronikIn Stock: 1192140817140010 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the EL817 are classified based on strict equivalence in the following critical parameters:

Mandatory Equivalence Criteria:

• Isolation Voltage: 5000Vrms
• Number of Channels: 1
• Output Type: Transistor
• Input Type: DC
• Package / Case: 4-DIP (0.300", 7.62mm)
• Mounting Type: Through Hole
• Operating Temperature Range: -55°C ~ 110°C
• Vce Saturation (Max): 200mV
• Rise / Fall Time (Typ): 4µs, 3µs (within tolerance)

Variable Parameters Allowing Substitution:

• Current Transfer Ratio (Min/Max): Ranges vary by part grade
• Voltage - Output (Max): 35V to 70V
• Current - DC Forward (If) (Max): 50mA to 60mA
• Voltage - Forward (Vf) (Typ): 1.2V to 1.24V

All identified substitute parts maintain the core isolation, channel, output, and package specifications while differing in current transfer ratio grades and maximum output voltage ratings.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Identical Current Transfer Ratio Range):

FOD817300 and FOD817D300 from Fairchild Semiconductor maintain the identical current transfer ratio range of 50% to 600% @ 5mA as the EL817. Both parts are active products with ROHS3 compliance status documented. FOD817300 carries 12,560 units in inventory; FOD817D300 carries 8,580 units. These parts differ from the EL817 in maximum output voltage (70V versus 35V) and current-DC forward specification (50mA versus 60mA), representing enhanced electrical capability.

140817140010 from Würth Elektronik (WL-OCPT series) provides parametric equivalence with identical current transfer ratio range (50% to 600% @ 5mA) and maintains the 35V maximum output voltage and 60mA forward current specifications of the EL817. This part is ROHS3 compliant and carries 1,172 units in inventory.

Grade-Specific Substitutes (Variable Current Transfer Ratio):

FOD817A300, FOD817B300, and FOD817C300 from onsemi represent higher current transfer ratio grades within the FOD817 family. FOD817A300 specifies 80% to 160% @ 5mA; FOD817B300 specifies 130% to 260% @ 5mA; FOD817C300 specifies 200% to 400% @ 5mA. All three parts are active products with ROHS3 compliance, maximum output voltage of 70V, and current-DC forward of 50mA. Inventory levels are 56,300 units (FOD817A300), 35,100 units (FOD817B300), and 32,088 units (FOD817C300).

Selection of grade-specific substitutes depends on circuit requirements for current transfer ratio performance. Applications requiring minimum current transfer ratio of 50% at 5mA input current accept FOD817300, FOD817D300, or 140817140010. Applications requiring higher current transfer ratio grades select FOD817A300, FOD817B300, or FOD817C300 based on specific performance thresholds.

Frequently Asked Questions (FAQ)

Q: Can FOD817300 replace EL817 in all applications?

A: FOD817300 maintains electrical equivalence in isolation voltage (5000Vrms), channel count (1), output type (transistor), input type (DC), package (4-DIP), mounting type (through hole), operating temperature range (-55°C to 110°C), and current transfer ratio range (50% to 600% @ 5mA). The maximum output voltage is higher (70V versus 35V), which does not restrict substitution in circuits designed for 35V operation. Current-DC forward specification differs (50mA versus 60mA), which does not affect substitution in circuits operating within 50mA limits.

Q: What is the difference between FOD817A300, FOD817B300, and FOD817C300?

A: These three parts are onsemi variants of the FOD817 optoisolator family differentiated by current transfer ratio grades. FOD817A300 specifies 80% to 160% @ 5mA; FOD817B300 specifies 130% to 260% @ 5mA; FOD817C300 specifies 200% to 400% @ 5mA. All three maintain identical isolation voltage, channel count, output type, package, and operating temperature specifications. Selection depends on circuit requirements for minimum and maximum current transfer ratio performance.

Q: Is 140817140010 from Würth Elektronik a direct substitute for EL817?

A: 140817140010 is a parametric equivalent. It maintains the identical current transfer ratio range (50% to 600% @ 5mA), maximum output voltage (35V), and current-DC forward specification (60mA) as the EL817. The part differs in forward voltage specification (1.24V versus 1.2V), which is within typical tolerance. Rise and fall times are specified in reverse order (3µs, 4µs versus 4µs, 3µs) but represent equivalent switching performance.

Q: Can I use FOD817D300 in place of EL817?

A: FOD817D300 maintains electrical equivalence in all critical parameters: isolation voltage (5000Vrms), channel count (1), output type (transistor), input type (DC), package (4-DIP), mounting type (through hole), operating temperature range (-55°C to 110°C), current transfer ratio range (300% to 600% @ 5mA), and Vce saturation (200mV). The maximum output voltage is higher (70V versus 35V). Current-DC forward is 50mA versus 60mA in the EL817. Substitution is valid for circuits operating within these electrical boundaries.

Q: What packaging differences exist between these substitute parts?

A: EL817 is supplied in Tube packaging; FOD817300 and FOD817D300 are supplied in Bulk packaging; FOD817A300, FOD817B300, FOD817C300, and 140817140010 are supplied in Tube packaging. All parts use identical 4-DIP (0.300", 7.62mm) through-hole package form factor and are mechanically interchangeable on printed circuit boards.

Q: Are all substitute parts ROHS3 compliant?

A: EL817, FOD817A300, FOD817B300, FOD817C300, and 140817140010 are documented as ROHS3 compliant. FOD817300 and FOD817D300 from Fairchild Semiconductor do not specify RoHS status in the provided data. Compliance verification with Fairchild documentation is required for applications with RoHS requirements.

Q: Which substitute part has the highest current inventory?

A: FOD817A300 from onsemi carries the highest inventory level at 56,300 units, followed by EL817 at 55,300 units. FOD817B300 carries 35,100 units; FOD817C300 carries 32,088 units; FOD817300 carries 12,560 units; FOD817D300 carries 8,580 units; and 140817140010 carries 1,172 units.