ISQ201 Equivalent & Substitute Parts

Part Overview

The ISQ201 is a quad-channel optoisolator with transistor output manufactured by Isocom Components 2004 LTD. This 16-pin DIP component provides galvanic isolation with a 7.5Vpk isolation voltage rating and is designed for DC input applications requiring transistor-switched outputs. The device is currently in active production status with 1427 units available in stock.

Finding equivalent or substitute parts may be necessary due to supply chain constraints, design requirement changes, or application-specific performance needs while maintaining package compatibility and isolation functionality.

Substiute Parts

ISQ201

Isocom Components 2004 LTDIn Stock: 1494ISQ201 Datasheet

Current PartRFQ

ILQ74

Vishay Semiconductor Opto DivisionIn Stock: 4197ILQ74 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

The ILQ74 from Vishay Semiconductor Opto Division is identified as a substitute for the ISQ201. Substitution eligibility is determined by the following critical parameters:

• Package Compatibility: Both devices use 16-DIP (0.300", 7.62mm) through-hole mounting, ensuring mechanical and electrical pin compatibility
• Output Type: Both feature transistor output configuration for switched load control
• Input Type: Both accept DC input signals
• Isolation Voltage: The ILQ74 provides 5300Vrms isolation, which exceeds the ISQ201's 7.5Vpk requirement, offering enhanced isolation capability
• Operating Temperature Range: The ILQ74 extends to -55°C, providing broader temperature coverage than the ISQ201's -25°C minimum
• Compliance Standards: Both devices are ROHS3 compliant, REACH unaffected, and share identical ECCN and HTSUS classifications
• Moisture Sensitivity: Both rated MSL 1 (Unlimited)

The primary design difference is channel count: the ILQ74 provides 4 channels versus the ISQ201's single channel, requiring circuit-level evaluation for multi-channel applications.

Parameter Comparison

Engineering Selection Recommendations

The ISQ201 maintains active production status with established supply availability. The ILQ74 is designated as Last Time Buy, indicating discontinued production with limited remaining inventory.

For new designs or long-term production requirements, the ISQ201 is the preferred selection due to its active status and ongoing manufacturer support. The ILQ74 may be considered only for applications where the extended isolation voltage (5300Vrms versus 7.5Vpk) and broader operating temperature range (-55°C to 100°C) provide specific functional advantages, and where the reduced maximum output voltage (20V versus 70V) and lower current transfer ratio (12.5% versus 75%) are acceptable within the application circuit design.

Both devices meet identical compliance requirements (ROHS3, REACH unaffected, EAR99 ECCN classification), ensuring regulatory equivalence for applications subject to these standards.

Frequently Asked Questions (FAQ)

Q: Can the ILQ74 be used as a direct pin-for-pin replacement for the ISQ201?

A: Both devices use identical 16-DIP (0.300", 7.62mm) through-hole packaging. However, the ILQ74 provides 4 channels while the ISQ201 provides 1 channel. Pin-level compatibility requires verification against specific application circuit requirements and channel utilization.

Q: What are the key electrical differences between these optoisolators?

A: The ISQ201 offers higher maximum output voltage (70V versus 20V) and significantly higher current transfer ratio (75% versus 12.5%). The ILQ74 provides superior isolation voltage (5300Vrms versus 7.5Vpk) and extended temperature range (-55°C to 100°C versus -25°C to 100°C).

Q: Why is the ILQ74 marked as Last Time Buy?

A: Last Time Buy status indicates the manufacturer has discontinued production. Existing inventory may be available through authorized distributors, but long-term supply cannot be guaranteed. New designs should prioritize the active ISQ201.

Q: Are there compliance or certification differences between these parts?

A: Both devices are ROHS3 compliant, REACH unaffected, and share identical ECCN (EAR99) and HTSUS (8541.49.8000) classifications. No compliance differentiation exists between the two optoisolators.

Q: What is the significance of the current transfer ratio difference?

A: Current transfer ratio determines the efficiency of signal transfer from input to output. The ISQ201's 75% ratio at 10mA indicates higher efficiency than the ILQ74's 12.5% at 16mA. Applications requiring high-efficiency isolation should prioritize the ISQ201.