OP775D Equivalent & Substitute Parts

Part Overview

The OP775D is a phototransistor optical sensor manufactured by TT Electronics/Optek Technology, designed for 935nm infrared detection in side view radial configuration. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing system support and new design implementations. The OP775D operates across a wide temperature range (-40°C to 100°C) with a maximum collector-emitter breakdown voltage of 30V and collector current rating of 5.5mA.

Substiute Parts

OP775D

TT Electronics/Optek TechnologyIn Stock: 1066OP775D Datasheet

Current PartRFQ

PT908-7C-F

Everlight Electronics Co LtdIn Stock: 45108PT908-7C-F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the OP775D is determined by the following critical parameters:

• Wavelength compatibility: 935nm detection capability with tolerance for near-infrared spectrum variants (940nm acceptable for most applications)
• Electrical ratings: Collector-emitter breakdown voltage minimum 30V, collector current capacity minimum 5.5mA
• Dark current specification: Maximum 100nA to maintain signal integrity
• Mechanical compatibility: Through-hole mounting, side view radial package configuration
• Environmental compliance: ROHS3 compliance and MSL rating of 1 (Unlimited)
• Temperature operating range: Minimum -40°C to 100°C or equivalent coverage

The PT908-7C-F meets these substitution criteria as an active product with compatible electrical and mechanical specifications.

Parameter Comparison

Engineering Selection Recommendations

The PT908-7C-F is the designated substitute for the obsolete OP775D based on the following factors:

• Both components maintain ROHS3 compliance and MSL rating of 1 (Unlimited), ensuring regulatory and environmental compatibility
• Electrical specifications align across collector-emitter breakdown voltage (30V) and dark current (100nA)
• The PT908-7C-F provides superior collector current capacity (20mA versus 5.5mA), offering design margin for current-limited applications
• Wavelength shift from 935nm to 940nm remains within acceptable near-infrared detection parameters for most optical sensing applications
• Through-hole radial side-view package configuration ensures mechanical interchangeability in existing PCB layouts
• Active product status of PT908-7C-F guarantees long-term availability and supply chain continuity

Selection of PT908-7C-F is appropriate for applications where the operating temperature range of -25°C to 85°C satisfies system requirements. Applications requiring the full -40°C to 100°C range of the original OP775D require alternative evaluation.

Frequently Asked Questions (FAQ)

Q: Can PT908-7C-F directly replace OP775D in existing designs?

A: PT908-7C-F is mechanically and electrically compatible for applications operating within -25°C to 85°C. The 940nm wavelength is compatible with 935nm detection circuits. Verify that your application does not require the extended low-temperature performance (-40°C) of the original OP775D.

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

A: Both wavelengths operate in the near-infrared spectrum. The 5nm difference is typically transparent to optical sensing applications using standard infrared LEDs and filters. Circuit performance remains equivalent for standard detection applications.

Q: Are there any compliance differences between OP775D and PT908-7C-F?

A: Both components are ROHS3 compliant with MSL rating of 1 (Unlimited). No compliance barriers exist for substitution.

Q: Why does PT908-7C-F have a higher maximum collector current rating?

A: The PT908-7C-F is rated for 20mA maximum collector current compared to 5.5mA for OP775D. This higher rating provides additional design margin and does not prevent substitution. Existing circuit designs operating within the 5.5mA limit remain fully compatible.

Q: Is the narrower operating temperature range of PT908-7C-F a concern?

A: The PT908-7C-F operates from -25°C to 85°C, compared to -40°C to 100°C for OP775D. Substitution is appropriate only for applications operating within this narrower range. Applications requiring extended temperature performance must pursue alternative solutions.

Q: What is the package compatibility between these components?

A: Both components use through-hole radial side-view packages. Physical footprint and PCB mounting are compatible without modification.