OP755B Equivalent & Substitute Parts

Part Overview

The OP755B is a 935nm side view radial phototransistor manufactured by TT Electronics/Optek Technology. This optical sensor is designed for infrared detection applications requiring through-hole mounting with radial orientation. The part is classified as obsolete, making equivalent substitutes necessary for new designs and ongoing production support. The OP755B operates across an extended temperature range of -40°C to 100°C with a maximum collector current of 30 mA and dark current specification of 100 nA.

Substiute Parts

OP755B

TT Electronics/Optek TechnologyIn Stock: 1109OP755B Datasheet

Current PartRFQ

LTR-301

Lite-On Inc.In Stock: 269158LTR-301 Datasheet

MFR RecommendedRFQ

LTR-301

Lite-On Inc.In Stock: 269158LTR-301 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the OP755B is based on the following critical parameters that define functional equivalence:

• Mounting Type & Orientation: Through hole mounting with side view radial package
• Voltage Rating: Collector-emitter breakdown voltage of 30 V
• Dark Current: Maximum 100 nA specification
• Wavelength Compatibility: Infrared detection in the 935nm-940nm range
• Power Dissipation: Maximum power rating capability
• Compliance: ROHS3 compliance and REACH unaffected status

The LTR-301 from Lite-On Inc. meets these substitution criteria as an active product with identical mounting configuration, voltage rating, dark current specification, and regulatory compliance. The wavelength shift from 935nm to 940nm represents a minor spectral variation within the near-infrared detection band suitable for most infrared applications.

Parameter Comparison

Engineering Selection Recommendations

The LTR-301 serves as the primary substitute for the obsolete OP755B. Both components share identical electrical ratings for voltage breakdown and dark current, matching mechanical form factors, and equivalent regulatory compliance certifications. The LTR-301 is an active product with established supply chain availability, addressing the obsolescence status of the OP755B.

Design considerations for substitution include the reduced maximum collector current (2.4 mA versus 30 mA) and lower maximum power dissipation (100 mW versus 200 mW) of the LTR-301. Applications requiring the full 30 mA collector current capability of the OP755B must evaluate whether the LTR-301 current specification meets functional requirements. The operating temperature upper limit of the LTR-301 is 85°C compared to 100°C for the OP755B; applications operating above 85°C require thermal management review.

Frequently Asked Questions (FAQ)

Q: Can the LTR-301 directly replace the OP755B in existing designs?

A: The LTR-301 shares identical mounting configuration (through-hole radial), voltage rating (30 V), and dark current specification (100 nA) with the OP755B. Direct mechanical and electrical compatibility exists for the package and primary electrical parameters. Circuit designs must account for the reduced maximum collector current (2.4 mA) and power dissipation (100 mW) of the LTR-301.

Q: What is the significance of the wavelength difference between 935nm and 940nm?

A: Both wavelengths operate within the near-infrared detection band. The 5nm spectral difference represents a minor variation in peak response wavelength. Applications using infrared LEDs or light sources in the 935nm-940nm range will function with either component. Spectral filtering or application-specific wavelength requirements should be evaluated against the actual light source characteristics.

Q: Are there any compliance or regulatory differences between the OP755B and LTR-301?

A: Both components are ROHS3 compliant and REACH unaffected. Regulatory compliance is equivalent for both parts. No additional compliance review is required from a regulatory standpoint.

Q: What should be considered regarding the operating temperature range difference?

A: The OP755B operates to 100°C while the LTR-301 operates to 85°C. Applications requiring operation above 85°C must retain the OP755B or identify alternative components with higher temperature ratings. For applications within the -40°C to 85°C range, the LTR-301 meets all temperature specifications.

Q: How does the reduced collector current of the LTR-301 affect circuit design?

A: The LTR-301 maximum collector current is 2.4 mA compared to 30 mA for the OP755B. Circuit designs must ensure that load resistances and bias configurations do not require collector currents exceeding 2.4 mA. Low-current signal detection applications are unaffected; high-current output applications require circuit redesign or alternative component selection.