OP793B Phototransistor 890nm Top View TO-18-2

Part Overview

The OP793B is a phototransistor optical sensor manufactured by TT Electronics/Optek Technology, designed for 890nm wavelength detection in a top view TO-18-2 package configuration. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support, design updates, and procurement continuity. The phototransistor operates through photoelectric conversion, where incident light at 890nm wavelength generates a collector current proportional to light intensity.

Substiute Parts

OP793B

TT Electronics/Optek TechnologyIn Stock: 1106OP793B Datasheet

Current PartRFQ

MTD8600T-T

Marktech OptoelectronicsIn Stock: 1246MTD8600T-T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the OP793B is determined by strict alignment of the following critical parameters:

• Wavelength Sensitivity: The substitute must operate within the near-infrared spectrum at or near 890nm. The MTD8600T-T operates at 880nm, representing a 10nm offset within acceptable tolerance for most optical detection applications utilizing similar light sources.
• Electrical Ratings: Maximum collector-emitter breakdown voltage (30V), maximum collector current (50mA), and maximum dark current (100nA) must be met or exceeded by the substitute.
• Power Dissipation: Maximum power rating of 250mW must be maintained.
• Package Compatibility: Both the main part and substitute must use TO-18-2 package configuration to ensure mechanical and electrical pin compatibility in existing circuit designs.
• Mounting Configuration: Through-hole mounting with top view orientation must be preserved for PCB layout compatibility.
• Operating Temperature Range: The substitute must support the required thermal operating window.

The MTD8600T-T from Marktech Optoelectronics meets all substitution criteria and is classified as an active product, providing long-term availability and supply chain stability.

Parameter Comparison

Engineering Selection Recommendations

The MTD8600T-T is the qualified substitute for the obsolete OP793B based on the following engineering criteria:

• Electrical Equivalence: All critical electrical parameters—breakdown voltage, maximum collector current, dark current, and power dissipation—are identical between the main part and substitute.
• Optical Compatibility: The 880nm wavelength of the MTD8600T-T is within 10nm of the OP793B's 890nm specification. This variance is acceptable for applications using standard near-infrared light sources in the 880–890nm band.
• Package and Mechanical Compatibility: Both components use TO-18-2 through-hole packages with top view orientation, ensuring direct PCB layout compatibility without redesign.
• Compliance and Certification: The MTD8600T-T is RoHS compliant and carries the same MSL rating as the OP793B, meeting regulatory and environmental requirements.
• Product Status and Supply: The MTD8600T-T is classified as active, providing assured long-term availability and supply chain continuity compared to the obsolete OP793B.
• Temperature Operating Range: The MTD8600T-T supports -30°C to 100°C operation. Applications requiring operation below -30°C must be evaluated separately.

Frequently Asked Questions (FAQ)

Q: Can the MTD8600T-T directly replace the OP793B without circuit modifications?

A: Yes, for most applications. Both components share identical electrical ratings (30V breakdown, 50mA max collector current, 100nA dark current, 250mW power) and use the same TO-18-2 through-hole package with top view orientation. Pin-for-pin compatibility is maintained. However, the 10nm wavelength difference (880nm vs. 890nm) should be verified against your specific light source and optical system design.

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

A: The 10nm variance represents approximately 1.1% difference in wavelength. For most optical detection applications using standard near-infrared LEDs or light sources in the 880–890nm range, this difference is within acceptable tolerance. Applications with narrowband optical filters or highly specific wavelength requirements should confirm compatibility with system-level testing.

Q: Does the MTD8600T-T have a narrower operating temperature range than the OP793B?

A: Yes. The OP793B operates from -40°C to 100°C, while the MTD8600T-T operates from -30°C to 100°C. The substitute has a 10°C higher minimum temperature limit. If your application requires operation below -30°C, the MTD8600T-T may not be suitable without additional thermal management or alternative component selection.

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

A: Both components are RoHS compliant and carry MSL rating 1 (Unlimited). The OP793B is ROHS3 compliant, while the MTD8600T-T is RoHS compliant. Both share identical ECCN (EAR99) and HTSUS classifications, indicating no regulatory barriers to substitution.

Q: What viewing angle does the MTD8600T-T provide?

A: The MTD8600T-T has a specified viewing angle of 110°. The OP793B viewing angle specification was not provided in the available data. For applications with specific angular sensitivity requirements, this parameter should be confirmed against system design specifications.

Q: Is the MTD8600T-T available in the same packaging format?

A: Yes. Both components use TO-18-2 package configuration. The MTD8600T-T is specified as TO-18-2 Metal Can, which is mechanically and electrically compatible with the OP793B TO-18-2 package for through-hole PCB mounting.