QSD722 Equivalent & Substitute Parts

Part Overview

The QSD722 is a phototransistor optical sensor manufactured by onsemi, designed for 880nm wavelength detection in a top-view TO-18-2 package configuration. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The QSD722 operates through hole mounting and is suitable for applications requiring photoelectric sensing in the near-infrared spectrum.

Substiute Parts

QSD722

onsemiIn Stock: 978QSD722 Datasheet

Current PartRFQ

OP598A

TT Electronics/Optek TechnologyIn Stock: 1656OP598A Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the QSD722 is determined by the following critical parameters:

• Package / Case: TO-18-2 (physical and electrical interface compatibility)
• Mounting Type: Through Hole (PCB assembly method)
• Orientation: Top View (optical axis alignment)
• Wavelength: 880nm nominal (near-infrared detection band)
• Voltage - Collector Emitter Breakdown: 30 V minimum
• Current - Dark (Id): 100 nA maximum (dark current specification)
• Operating Temperature Range: -40°C ~ 100°C (thermal operating envelope)

The OP598A qualifies as an equivalent substitute based on matching package, mounting type, orientation, and operating temperature specifications. The wavelength specification of 890nm represents a 10nm offset within the near-infrared detection band, maintaining functional compatibility for typical 880nm sensing applications. Electrical characteristics including breakdown voltage and dark current specifications are met or exceeded.

Parameter Comparison

Engineering Selection Recommendations

The OP598A is qualified as a direct substitute for the QSD722 based on the following engineering criteria:

All critical mechanical parameters align: TO-18-2 package, through-hole mounting, and top-view orientation ensure direct PCB compatibility without redesign.

Electrical specifications are met or exceeded: The OP598A maintains the 30 V collector-emitter breakdown voltage and 100 nA maximum dark current, with enhanced power dissipation capability (250 mW versus 100 mW).

Wavelength compatibility: The 890nm specification of the OP598A operates within the near-infrared detection band and is functionally compatible with 880nm sensing applications.

Product status advantage: The OP598A is actively manufactured by TT Electronics/Optek Technology, ensuring long-term availability and supply chain continuity compared to the obsolete QSD722.

Compliance alignment: Both components share identical moisture sensitivity levels and REACH compliance status, maintaining regulatory consistency in design transitions.

Frequently Asked Questions (FAQ)

Q: Can the OP598A be used as a direct replacement for the QSD722 without PCB modifications?

A: Yes. Both components use the TO-18-2 package with identical through-hole mounting and top-view orientation. No PCB layout changes are required for physical installation.

Q: What is the significance of the 10nm wavelength difference between 880nm and 890nm?

A: The 10nm offset represents a minor shift within the near-infrared detection band. For typical 880nm sensing applications, the OP598A maintains functional compatibility. Applications with narrow-band wavelength filtering may require optical characterization.

Q: Does the OP598A's higher power rating (250 mW vs. 100 mW) affect circuit design?

A: The higher power rating of the OP598A provides additional thermal margin and does not require circuit modifications. Existing designs rated for the QSD722's 100 mW specification will operate safely with the OP598A.

Q: Are there compliance or certification differences between the two parts?

A: Both components share identical moisture sensitivity levels (MSL 1) and REACH compliance status. No compliance-related design changes are necessary for substitution.

Q: What is the availability status of each component?

A: The QSD722 is classified as obsolete. The OP598A is actively manufactured and maintained in production inventory, ensuring reliable long-term supply for new designs and production continuity.