OP521DA Phototransistor 935nm Top View 1206 Equivalent & Substitute Parts

Part Overview

The OP521DA is a phototransistor optical sensor manufactured by TT Electronics / Optek Technology, designed for 935nm infrared detection in a 1206 (3216 Metric) surface mount package with top view orientation. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and production continuity. The OP521DA operates across a temperature range of -25°C to 85°C and is ROHS3 compliant.

Substiute Parts

OP521DA

TT Electronics / Optek TechnologyIn Stock: 1049OP521DA Datasheet

Current PartRFQ

PT15-21C/TR8

Everlight Electronics Co LtdIn Stock: 51039PT15-21C/TR8 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the OP521DA is determined by the following critical parameters:

• Package / Case: 1206 (3216 Metric) surface mount package
• Orientation: Top view configuration
• Mounting Type: Surface mount
• Operating Temperature Range: -25°C ~ 85°C
• Wavelength: Near-infrared detection in the 935nm–940nm range
• Electrical Ratings: Collector-emitter breakdown voltage, maximum collector current, and dark current specifications

The PT15-21C/TR8 phototransistor from Everlight Electronics Co Ltd meets these substitution criteria. While the wavelength differs slightly (940nm versus 935nm), both operate within the near-infrared spectrum suitable for comparable optical sensing applications. The PT15-21C/TR8 maintains identical package geometry, mounting type, and orientation, with compatible electrical performance within the specified operating temperature range.

Parameter Comparison

Engineering Selection Recommendations

The PT15-21C/TR8 is the designated manufacturer-recommended substitute for the obsolete OP521DA. Both components maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory alignment for new production. The PT15-21C/TR8 is currently in active production status, providing supply continuity and long-term availability.

Electrical parameter differences exist between the two components. The PT15-21C/TR8 exhibits lower maximum ratings for collector-emitter breakdown voltage (30 V versus 35 V), maximum collector current (20 mA versus 30 mA), and maximum power dissipation (75 mW versus 100 mW). The PT15-21C/TR8 also demonstrates superior dark current performance (100 nA versus 200 nA), indicating lower leakage current in the absence of incident light.

The wavelength difference of 5nm (940nm versus 935nm) falls within the near-infrared spectrum and is compatible with optical sensing applications designed for the OP521DA, provided the application does not require wavelength-specific filtering or detection.

Frequently Asked Questions (FAQ)

Q: Can the PT15-21C/TR8 be used as a direct replacement for the OP521DA in existing designs?

A: The PT15-21C/TR8 is mechanically and functionally compatible with the OP521DA due to identical package geometry (1206), mounting type (surface mount), and orientation (top view). However, circuit designs must account for the lower electrical ratings of the PT15-21C/TR8, particularly the reduced maximum collector current (20 mA versus 30 mA) and power dissipation (75 mW versus 100 mW). Applications operating near the OP521DA's maximum ratings may require circuit redesign.

Q: What is the significance of the 5nm wavelength difference between 935nm and 940nm?

A: Both wavelengths operate within the near-infrared spectrum and are suitable for comparable optical sensing applications. The 5nm difference is negligible for most general-purpose infrared detection circuits. Applications requiring wavelength-specific performance or narrow-band filtering should evaluate spectral response characteristics against application requirements.

Q: Why does the PT15-21C/TR8 have a higher Moisture Sensitivity Level (MSL 3 versus MSL 2)?

A: MSL 3 (168 hours) indicates a shorter shelf life in humid conditions compared to MSL 2 (1 year). This affects storage and handling procedures but does not impact electrical performance or field operation. Proper moisture control during storage and handling is required for the PT15-21C/TR8.

Q: Is the PT15-21C/TR8 available in packaging formats other than Tape & Reel?

A: The provided data specifies the PT15-21C/TR8 in Tape & Reel (TR) packaging. The base product number PT15-21 may be available in alternative packaging configurations; consult the manufacturer for packaging options.

Q: Are both components suitable for the same operating temperature range?

A: Yes. Both the OP521DA and PT15-21C/TR8 operate across -25°C to 85°C, ensuring thermal compatibility in equivalent applications.