OP798C Equivalent & Substitute Parts

Part Overview

The OP798C is a phototransistor optical sensor manufactured by TT Electronics / Optek Technology, designed for 890nm wavelength detection in a TO-18-2 through-hole package. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing production and maintenance applications. The OP798C operates across an extended temperature range of -40°C to 100°C with a maximum collector current of 50 mA and dark current specification of 100 nA maximum.

Substiute Parts

OP798C

TT Electronics / Optek TechnologyIn Stock: 687OP798C Datasheet

Current PartRFQ

MTD8600N-T

Marktech OptoelectronicsIn Stock: 1129MTD8600N-T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the OP798C is determined by the following critical parameters:

• Package Compatibility: TO-18-2 through-hole configuration required for mechanical and electrical interface compatibility
• Wavelength Specification: 890nm nominal detection wavelength; 880nm represents acceptable operational variance within phototransistor sensor specifications
• Electrical Ratings: Collector-emitter breakdown voltage of 30 V, maximum collector current of 50 mA, and dark current maximum of 100 nA must be maintained or exceeded
• Mounting and Orientation: Top view orientation in through-hole configuration
• Power Dissipation: 250 mW maximum power rating
• Temperature Range: Operating temperature capability must support the required application range

The MTD8600N-T from Marktech Optoelectronics meets these substitution criteria with equivalent electrical specifications and compatible packaging.

Parameter Comparison

Engineering Selection Recommendations

The MTD8600N-T is an active production substitute for the obsolete OP798C. Both components maintain identical electrical specifications for collector-emitter breakdown voltage, maximum collector current, dark current, and power dissipation. The TO-18-2 through-hole package configuration is mechanically and electrically compatible between both parts.

The MTD8600N-T operates across a narrower lower temperature range (-30°C to 100°C) compared to the OP798C (-40°C to 100°C). Applications requiring operation below -30°C require evaluation against specific system requirements.

Both components maintain equivalent RoHS and REACH compliance status. The MTD8600N-T is currently in active production with established supply availability, whereas the OP798C is obsolete.

Frequently Asked Questions (FAQ)

Q: Can the MTD8600N-T directly replace the OP798C in existing designs?

A: Yes. Both components share identical electrical ratings (30 V breakdown, 50 mA maximum collector current, 100 nA dark current, 250 mW power dissipation) and compatible TO-18-2 through-hole packaging with top view orientation. The 10nm wavelength difference (890nm to 880nm) falls within normal phototransistor sensor operational variance.

Q: What is the impact of the operating temperature range difference?

A: The OP798C operates from -40°C to 100°C, while the MTD8600N-T operates from -30°C to 100°C. Applications requiring operation below -30°C must evaluate whether the narrower temperature range of the MTD8600N-T is acceptable for the specific system requirements.

Q: Are the packages mechanically identical?

A: Both components use TO-18-2 through-hole packages with top view orientation. The MTD8600N-T is specified as a metal can variant, which is mechanically and electrically compatible with the OP798C TO-18-2 configuration.

Q: What compliance certifications apply to both parts?

A: The OP798C is ROHS3 compliant and REACH unaffected. The MTD8600N-T is RoHS compliant and REACH unaffected. Both components maintain MSL 1 (unlimited) moisture sensitivity classification.

Q: Is the wavelength difference significant for substitution?

A: The wavelength difference of 10nm (890nm to 880nm) is within acceptable operational variance for phototransistor sensors in this category. Both wavelengths fall within the near-infrared spectrum and are suitable for equivalent optical detection applications.