EL817(C) Optoisolator Equivalent & Substitute Parts

Part Overview

The EL817(C) is a single-channel optoisolator with transistor output manufactured by Everlight Electronics Co Ltd. This component provides 5000Vrms isolation and is designed for DC input applications requiring galvanic isolation in 4-DIP through-hole packages. The part is active and in production status with 1599 units currently in stock.

Substitute parts are necessary to address supply chain continuity, alternative sourcing options, and application-specific performance requirements within the optoisolator category. Equivalent parts maintain the same functional isolation voltage, package form factor, and output characteristics while potentially offering different current transfer ratio specifications or manufacturer availability.

Substiute Parts

EL817(C)

Everlight Electronics Co LtdIn Stock: 1660EL817(C) 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

140817140310

Würth ElektronikIn Stock: 1063140817140310 Datasheet

Parametric EquivalentRFQ

Q817C

QT Brightek (QTB)In Stock: 1279Q817C Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution logic for the EL817(C) optoisolator is based on the following critical parameters that must remain constant across all equivalent parts:

Mandatory Matching Parameters:

• Voltage - Isolation: 5000Vrms
• Number of Channels: 1
• Output Type: Transistor
• Input Type: DC
• Package / Case: 4-DIP (0.300", 7.62mm)
• Mounting Type: Through Hole
• Current - Output / Channel: 50mA
• Operating Temperature Range: -55°C to 110°C
• Vce Saturation (Max): 200mV

Variable Parameters (Allowed to Differ):

• Current Transfer Ratio (Min/Max): Ranges from 50% to 600% @ 5mA depending on part grade
• Voltage - Output (Max): 35V to 70V depending on manufacturer
• Voltage - Forward (Vf) (Typ): 1.2V to 1.24V
• Current - DC Forward (If) (Max): 50mA to 60mA
• Rise / Fall Time (Typ): 3µs to 8µs depending on part grade

Substitute parts are grouped into two categories: direct functional equivalents from alternative manufacturers (FOD817 series from Fairchild Semiconductor and onsemi) and parametric equivalents (Würth Elektronik 140817140310 and QT Brightek Q817C) that maintain identical electrical performance within specified tolerances.

Parameter Comparison

Engineering Selection Recommendations

Direct Functional Equivalents (Recommended for Pin-Compatible Replacement):

FOD817C300 (onsemi) and FOD817B300 (onsemi) provide the closest electrical match to the EL817(C) with identical current transfer ratio specifications (200%-400% @ 5mA). Both parts are ROHS3 compliant and available in high inventory quantities (32,088 and 35,100 units respectively). FOD817C300 is the primary equivalent with matching CTR specifications and is suitable for direct substitution in applications where the 35V output voltage rating of the EL817(C) is sufficient.

For applications requiring higher output voltage capability, FOD817A300 (onsemi) and FOD817300 (Fairchild Semiconductor) offer 70V maximum output voltage with the same 5000Vrms isolation and 4-DIP package. FOD817A300 provides 80%-160% CTR and FOD817300 provides 50%-600% CTR, both with 56,300 and 12,560 units in stock respectively.

FOD817D300 (Fairchild Semiconductor) offers the highest current transfer ratio range (300%-600% @ 5mA) with 70V output capability and 8,580 units available.

Parametric Equivalents (Identical Performance Specifications):

140817140310 (Würth Elektronik) from the WL-OCPT series matches the EL817(C) exactly in current transfer ratio (200%-400% @ 5mA), output voltage (35V), and forward current specifications (60mA max). This part is ROHS3 compliant with 1,012 units in stock. Rise and fall times are reversed (3µs, 4µs vs. 4µs, 3µs) but remain within equivalent performance parameters.

Q817C (QT Brightek) from the Q817 series provides identical CTR (200%-400% @ 5mA) and output voltage (35V) specifications with 1,252 units available. Rise and fall times are slower (6µs, 8µs) compared to the EL817(C), which may impact switching speed-sensitive applications.

Compliance and Certification:

All substitute parts listed are ROHS3 compliant and carry EAR99 export classification. The EL817(C), 140817140310, and Q817C specify Moisture Sensitivity Level 1 (Unlimited). FOD817 series parts from onsemi indicate MSL as Not Applicable. All parts are classified under HTSUS 8541.49.8000.

Frequently Asked Questions (FAQ)

Q: Can FOD817300 replace EL817(C) in all applications?

A: FOD817300 is electrically compatible for isolation voltage, channel count, package, and mounting type. However, it differs in current transfer ratio range (50%-600% vs. 200%-400%) and maximum output voltage (70V vs. 35V). Applications requiring the 35V output limit of the EL817(C) should use FOD817C300 instead for closer specification matching.

Q: What is the difference between FOD817A300, FOD817B300, FOD817C300, and FOD817D300?

A: These onsemi parts differ in current transfer ratio specifications. FOD817A300 provides 80%-160% CTR, FOD817B300 provides 130%-260% CTR, FOD817C300 provides 200%-400% CTR (matching EL817(C)), and FOD817D300 (Fairchild) provides 300%-600% CTR. All maintain identical isolation voltage, package, and output current ratings. Selection depends on the required CTR range for the application circuit.

Q: Is the 4-DIP package identical across all substitute parts?

A: Yes. All substitute parts use the 4-DIP (0.300", 7.62mm) through-hole package with identical pin spacing and mounting requirements. Direct PCB substitution is possible without layout modifications.

Q: How do rise and fall times affect substitution?

A: The EL817(C) specifies 4µs rise time and 3µs fall time. FOD817 series parts maintain identical timing (4µs, 3µs). The 140817140310 reverses these values (3µs, 4µs) with negligible practical difference. Q817C specifies slower timing (6µs, 8µs), which may impact applications with strict switching speed requirements above 100kHz.

Q: Are there inventory considerations for substitution?

A: FOD817C300 (onsemi) offers the highest inventory at 32,088 units, followed by FOD817B300 at 35,100 units. The EL817(C) has 1,599 units in stock. For supply chain continuity, FOD817C300 is the preferred substitute with both high availability and exact CTR matching.

Q: What is the maximum forward current difference between EL817(C) and FOD817 substitutes?

A: The EL817(C) specifies 60mA maximum DC forward current, while most FOD817 variants specify 50mA. This 10mA difference may be significant in LED drive circuits operating near maximum ratings. The 140817140310 and Q817C maintain the 60mA specification matching the EL817(C).

Q: Can I use FOD817D300 where EL817(C) is specified?

A: FOD817D300 is functionally compatible for isolation, package, and output current. However, its 300%-600% CTR range is higher than the EL817(C) specification (200%-400%). This part is suitable only if the application circuit tolerates higher current transfer ratios or if the design includes current-limiting provisions.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts carry ROHS3 compliance certification. The EL817(C), 140817140310, and Q817C explicitly state ROHS3 Compliant status. FOD817 series parts from onsemi and Fairchild Semiconductor are also ROHS3 compliant.