OP291C Infrared Emitter 890nm Equivalent & Substitute Parts

Part Overview

The OP291C is a through-hole infrared emitter manufactured by TT Electronics / Optek Technology, designed for 890nm wavelength applications with 150mA forward current capability. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. Active alternatives with comparable electrical and mechanical characteristics are available from multiple manufacturers.

Substiute Parts

OP291C

TT Electronics / Optek TechnologyIn Stock: 769OP291C Datasheet

Current PartRFQ

OP291A

TT Electronics / Optek TechnologyIn Stock: 3055OP291A Datasheet

MFR RecommendedRFQ

IR333/H0

Everlight Electronics Co LtdIn Stock: 723IR333/H0 Datasheet

MFR RecommendedRFQ

LTE-3271B

Lite-On Inc.In Stock: 1171LTE-3271B Datasheet

MFR RecommendedRFQ

OP291A

TT Electronics / Optek TechnologyIn Stock: 3055OP291A Datasheet

MFR RecommendedRFQ

IR333/H0

Everlight Electronics Co LtdIn Stock: 723IR333/H0 Datasheet

MFR RecommendedRFQ

LTE-3271B

Lite-On Inc.In Stock: 1171LTE-3271B Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution logic for the OP291C is based on the following criteria:

Primary Equivalent (Direct Replacement):

• OP291A: Identical electrical specifications (890nm, 150mA, 2V, 50° viewing angle, T 1 3/4 package). Active product status with higher inventory availability. Mechanical and electrical compatibility is complete.

Secondary Alternatives (Functional Substitutes with Parameter Variations):

• IR333/H0 (Everlight Electronics): Different wavelength (940nm), reduced forward current (100mA), lower forward voltage (1.2V–1.4V), different package (Radial), reduced viewing angle (40°). Suitable only where 940nm wavelength is acceptable and circuit design accommodates lower current and voltage specifications.
• LTE-3271B (Lite-On Inc.): Different wavelength (940nm), reduced forward current (100mA), lower forward voltage (1.25V), different package (Radial), 50° viewing angle maintained. Suitable only where 940nm wavelength is acceptable and circuit design accommodates lower current and voltage specifications.

Parameter Comparison

Engineering Selection Recommendations

OP291A is the recommended primary substitute for OP291C. Both components share identical electrical specifications, mechanical packaging, and operating temperature range. OP291A maintains active product status with ROHS3 compliance and higher inventory availability (3028 pcs vs. 727 pcs for OP291C), ensuring long-term supply continuity.

IR333/H0 and LTE-3271B are functional alternatives only when application requirements permit wavelength shift from 890nm to 940nm and forward current reduction from 150mA to 100mA. These alternatives require circuit redesign validation. IR333/H0 operates at reduced temperature maximum (-40°C ~ 85°C vs. -40°C ~ 100°C) and uses a radial package requiring different PCB footprint. LTE-3271B maintains 50° viewing angle and ROHS3 compliance but also requires radial package accommodation and operates at reduced temperature maximum.

Frequently Asked Questions (FAQ)

Q: Can OP291A be used as a direct drop-in replacement for OP291C? A: Yes. OP291A is electrically and mechanically identical to OP291C. Both use T 1 3/4 through-hole packaging, operate at 890nm wavelength, support 150mA forward current, and maintain -40°C ~ 100°C operating temperature range. No circuit modifications are required.

Q: What are the key differences between OP291C and the 940nm alternatives? A: IR333/H0 and LTE-3271B operate at 940nm wavelength instead of 890nm, support only 100mA forward current instead of 150mA, and use radial packages instead of T 1 3/4 through-hole packages. These differences require circuit redesign and PCB layout changes. Operating temperature maximum is also reduced to -40°C ~ 85°C.

Q: Which substitute is suitable if wavelength must remain 890nm? A: OP291A is the only substitute maintaining 890nm wavelength. It is the direct equivalent to OP291C with active product status.

Q: Are all substitutes RoHS compliant? A: OP291A and LTE-3271B are ROHS3 compliant. IR333/H0 RoHS status is not specified in available documentation.

Q: What inventory considerations apply to these substitutes? A: OP291A has the highest inventory (3028 pcs), followed by LTE-3271B (1117 pcs) and IR333/H0 (703 pcs). OP291C inventory is 727 pcs but marked obsolete.

Q: Can 940nm emitters be used in 890nm detector circuits? A: Wavelength compatibility depends on detector spectral response. 940nm emitters operate outside the 890nm specification and may not provide adequate signal coupling with 890nm-optimized detectors. Circuit validation is required before substitution.