OP550B Phototransistor 935nm Side View Radial Equivalent & Substitute Parts

Part Overview

The OP550B is an active phototransistor manufactured by TT Electronics / Optek Technology, designed for 935nm infrared detection applications. This component operates in side view radial configuration with through-hole mounting. The OP550B remains in active production status with 1137 units currently in stock. Equivalent and substitute parts are identified to support component availability, supply chain continuity, and design flexibility when the primary part becomes unavailable or when alternative sourcing is required.

Substiute Parts

OP550B

TT Electronics / Optek TechnologyIn Stock: 1221OP550B Datasheet

Current PartRFQ

QSE114

onsemiIn Stock: 5054QSE114 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the OP550B are identified based on the following critical parameters that determine functional compatibility:

• Mounting Type: Through Hole (required match)
• Orientation: Side View (required match)
• Package / Case: Radial (required match)
• Voltage - Collector Emitter Breakdown (Max): 30 V (required match)
• Current - Dark (Id) (Max): 100 nA (required match)
• Power - Max: 100 mW (required match)
• Operating Temperature Range: -40°C ~ 100°C (required match)
• RoHS Status: ROHS3 Compliant (required match)

The QSE114 phototransistor from onsemi meets all critical electrical and mechanical parameters. The wavelength difference (880nm vs 935nm) represents a variation within the near-infrared spectrum and does not preclude substitution in applications where spectral sensitivity tolerance permits. The QSE114 includes a specified viewing angle of 50°, which is an additional parameter not provided for the OP550B but does not affect substitution eligibility.

Parameter Comparison

Engineering Selection Recommendations

Both the OP550B and QSE114 maintain active product status with current manufacturing support. Both components are ROHS3 compliant and REACH unaffected, meeting regulatory requirements for industrial and commercial applications. The QSE114 demonstrates higher inventory availability (4945 units) compared to the OP550B (1137 units), which may influence supply chain decisions. Both parts carry identical electrical ratings for collector-emitter breakdown voltage, dark current, and maximum power dissipation, ensuring functional equivalence in circuit design. Selection between these parts should be based on application-specific spectral sensitivity requirements and component availability at the time of procurement.

Frequently Asked Questions (FAQ)

Q: Can the QSE114 be used as a direct replacement for the OP550B in all applications?

A: The QSE114 is electrically and mechanically compatible with the OP550B. Both components share identical voltage ratings, dark current specifications, power ratings, and operating temperature ranges. The wavelength difference (880nm vs 935nm) must be evaluated against application requirements. If the circuit design depends on 935nm spectral response, the wavelength variation may affect performance.

Q: What is the significance of the wavelength difference between 935nm and 880nm?

A: Wavelength determines the infrared spectrum at which the phototransistor achieves peak sensitivity. The 55nm difference places both components in the near-infrared region but with different spectral response curves. Applications using matched infrared emitters must ensure the emitter wavelength aligns with the phototransistor's peak sensitivity for optimal performance.

Q: Are the radial packages of both parts identical?

A: Both the OP550B and QSE114 use radial through-hole packages with side view orientation. This ensures mechanical compatibility for PCB mounting and component replacement without requiring circuit board redesign.

Q: What compliance certifications apply to both parts?

A: Both the OP550B and QSE114 are ROHS3 compliant and REACH unaffected. These certifications confirm compliance with hazardous substance restrictions and environmental regulations applicable to electronic components in industrial markets.

Q: Which part should be selected for new designs?

A: Selection should be based on spectral sensitivity requirements, supplier availability, and lead time considerations. Both parts are active products with current manufacturing support. The QSE114 offers higher inventory availability, which may reduce procurement lead times.