OP798B Equivalent & Substitute Parts

Part Overview

The OP798B is a phototransistor optical sensor manufactured by TT Electronics/Optek Technology, designed for 890nm wavelength detection in a TO-18-2 through-hole package. The device features a collector-emitter breakdown voltage of 30V, maximum collector current of 50mA, and operates across a temperature range of -40°C to 100°C. This part is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing system support and new design implementations.

Substiute Parts

OP798B

TT Electronics/Optek TechnologyIn Stock: 1101OP798B Datasheet

Current PartRFQ

MTD8600N-T

Marktech OptoelectronicsIn Stock: 1129MTD8600N-T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the OP798B is determined by alignment across the following critical parameters:

Wavelength compatibility within the near-infrared spectrum (880-890nm range), identical package configuration (TO-18-2), matching electrical ratings (30V collector-emitter breakdown, 50mA maximum collector current, 100nA maximum dark current), equivalent power dissipation capability (250mW), and compatible mounting methodology (through-hole, top view orientation).

The MTD8600N-T from Marktech Optoelectronics meets these substitution criteria. While the MTD8600N-T operates at 880nm (10nm shorter wavelength than the OP798B), it maintains identical electrical ratings, package type, and mounting configuration. The operating temperature range differs slightly (-30°C to 100°C versus -40°C to 100°C), representing a narrower lower temperature bound.

Parameter Comparison

Engineering Selection Recommendations

The MTD8600N-T serves as a direct functional substitute for the OP798B in applications where the 880nm wavelength is acceptable within system design parameters. Both components maintain identical electrical specifications (30V breakdown voltage, 50mA collector current, 100nA dark current, 250mW power rating) and share the same TO-18-2 through-hole package configuration.

The MTD8600N-T holds active product status with current manufacturing availability, addressing the obsolescence constraint of the OP798B. Both components maintain equivalent RoHS compliance certifications and REACH unaffected status, supporting regulatory requirements.

The operating temperature differential (-30°C lower bound for MTD8600N-T versus -40°C for OP798B) requires verification against application-specific environmental specifications. Applications requiring operation below -30°C cannot utilize the MTD8600N-T as a substitute.

Frequently Asked Questions (FAQ)

Q: Can the MTD8600N-T replace the OP798B in all applications?

A: The MTD8600N-T is electrically and mechanically compatible with the OP798B across all specified parameters except operating temperature range. Applications operating below -30°C ambient temperature require the OP798B or alternative components rated to -40°C.

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

A: Both wavelengths fall within the near-infrared spectrum and are functionally equivalent for phototransistor applications. System design must confirm that the 880nm wavelength of the MTD8600N-T aligns with optical filter specifications and light source characteristics in the target application.

Q: Are the TO-18-2 packages physically identical?

A: Both components use TO-18-2 through-hole packages with top-view orientation. The MTD8600N-T specifies a metal can variant, which maintains dimensional and electrical compatibility with standard TO-18-2 configurations.

Q: What compliance certifications apply to both components?

A: Both the OP798B and MTD8600N-T maintain RoHS compliance and REACH unaffected status, supporting regulatory requirements for electronic component procurement and deployment.

Q: Is the MTD8600N-T currently available?

A: The MTD8600N-T holds active product status with documented inventory availability, providing supply chain continuity for applications transitioning from the obsolete OP798B.