QSD723 Equivalent & Substitute Parts

Part Overview

The QSD723 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 ongoing design support and procurement continuity. The QSD723 operates across an industrial temperature range of -40°C to 100°C and is suitable for through-hole mounting applications requiring photodetection in the near-infrared spectrum.

Substiute Parts

QSD723

onsemiIn Stock: 937QSD723 Datasheet

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OP598A

TT Electronics/Optek TechnologyIn Stock: 1656OP598A Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the QSD723 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 Range: 880nm nominal (near-infrared detection band)
• Voltage - Collector Emitter Breakdown: 30 V minimum (electrical stress rating)
• Current - Dark (Id): 100 nA maximum (dark current leakage specification)
• Operating Temperature Range: -40°C ~ 100°C (thermal operating envelope)

The OP598A qualifies as a substitute part based on matching all critical parameters within the allowed electrical and mechanical specifications for this optical sensor category.

Parameter Comparison

Engineering Selection Recommendations

The OP598A is a direct substitute for the QSD723 based on matching electrical ratings, package configuration, and operating temperature specifications. The OP598A maintains active product status with ROHS3 compliance certification, providing supply chain continuity for applications currently using the obsolete QSD723. The wavelength difference of 10nm (890nm versus 880nm) falls within the near-infrared detection band and does not disqualify substitution for standard photodetection applications. The OP598A offers increased maximum power dissipation (250 mW versus 100 mW), providing additional thermal margin in power-constrained designs.

Frequently Asked Questions (FAQ)

Q: Can the OP598A replace the QSD723 in existing designs without PCB modifications?

A: Yes. Both components share identical TO-18-2 package geometry, through-hole mounting configuration, and top-view optical orientation. No PCB layout changes are required for mechanical or electrical interface compatibility.

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

A: Both wavelengths operate within the near-infrared spectrum used for standard photodetection applications. The 10nm difference represents a 1.1% shift in center wavelength and does not affect substitution eligibility for applications designed around the 880nm specification.

Q: Are there compliance or certification differences between the QSD723 and OP598A?

A: The OP598A carries ROHS3 compliance certification, while the QSD723 product status is obsolete. Both components share identical REACH Unaffected status and EAR99 ECCN classification. The OP598A's active product status ensures ongoing manufacturer support and supply availability.

Q: Does the higher maximum power rating of the OP598A (250 mW versus 100 mW) affect circuit design?

A: The OP598A's increased power rating provides additional thermal headroom but does not require circuit modifications. Existing designs operating within the QSD723's 100 mW limit will operate safely with the OP598A without design changes.

Q: What is the Moisture Sensitivity Level (MSL) for both components?

A: Both the QSD723 and OP598A carry MSL 1 (Unlimited) classification, indicating no moisture sensitivity restrictions for storage, handling, or assembly processes.