SFH 4451 Equivalent & Substitute Parts

Part Overview

The SFH 4451 is an Infrared (IR) Emitter operating at 860nm wavelength, designed for surface mount applications requiring 100mA forward current and 1.5V forward voltage. This component is classified as Obsolete, necessitating identification of active equivalent parts for new designs and ongoing production requirements. The SFH 4451 delivers 70mW/sr radiant intensity at maximum rated current with a 34° viewing angle in a 2-SMD, No Lead package configuration.

Substiute Parts

SFH 4451

ams-OSRAM USA INC.In Stock: 1059SFH 4451 Datasheet

Current PartRFQ

SFH 4258-Z

ams-OSRAM USA INC.In Stock: 39229SFH 4258-Z Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SFH 4451 is determined by electrical and optical parameter alignment within the infrared emitter category. The primary substitution criteria are:

Electrical Parameters: Forward current (100mA maximum), forward voltage (1.5V typical), and wavelength (860nm) must remain constant to ensure circuit compatibility and optical performance.

Optical Parameters: Radiant intensity and viewing angle define the emission characteristics. The SFH 4451 specifies 70mW/sr at 100mA with a 34° viewing angle.

Environmental Compliance: RoHS3 compliance and REACH unaffected status are mandatory for regulatory alignment.

Mounting Configuration: Surface mount technology is required; however, package form factor may differ (2-SMD, No Lead versus 4-PLCC) provided the electrical and optical specifications remain within acceptable operational parameters.

The SFH 4258-Z qualifies as a substitute based on matching wavelength (860nm), forward current (100mA), forward voltage (1.5V), and compliance certifications, despite differences in package type and enhanced radiant intensity specification.

Parameter Comparison

Engineering Selection Recommendations

The SFH 4258-Z is an active substitute for the obsolete SFH 4451. Both components share identical electrical specifications (100mA forward current, 1.5V forward voltage, 860nm wavelength) and maintain equivalent regulatory compliance (ROHS3 Compliant, REACH Unaffected).

The SFH 4258-Z provides enhanced radiant intensity (110mW/sr versus 70mW/sr) and extended operating temperature range (-40°C to 100°C versus -40°C to 85°C), representing performance improvements over the original part. The narrower viewing angle (30° versus 34°) and different package configuration (4-PLCC versus 2-SMD, No Lead) require circuit board layout and optical design verification for specific applications.

Selection of the SFH 4258-Z is appropriate for applications where the original SFH 4451 is no longer available and where the enhanced optical output and extended temperature range do not create design constraints.

Frequently Asked Questions (FAQ)

Q: Can the SFH 4258-Z directly replace the SFH 4451 in existing designs?

A: Electrical compatibility is confirmed (100mA, 1.5V, 860nm). However, the package change from 2-SMD, No Lead to 4-PLCC requires circuit board layout modification. The increased radiant intensity (110mW/sr versus 70mW/sr) and narrower viewing angle (30° versus 34°) may affect optical performance in the application and must be evaluated against specific design requirements.

Q: What are the key electrical parameters that must match for substitution?

A: Forward current (100mA maximum), forward voltage (1.5V typical), and wavelength (860nm) are the critical electrical parameters. These parameters must remain constant to ensure circuit compatibility and optical performance.

Q: Are there compliance differences between the SFH 4451 and SFH 4258-Z?

A: Both components are ROHS3 Compliant and REACH Unaffected. Moisture Sensitivity Level (MSL) is identical at Level 2 (1 Year) for both parts. No compliance barriers exist for substitution.

Q: How does the viewing angle difference affect substitution suitability?

A: The SFH 4451 specifies a 34° viewing angle while the SFH 4258-Z specifies 30°. This narrower angle concentrates optical output, which may be advantageous in focused applications but requires evaluation in applications requiring wider angular distribution.

Q: What is the significance of the extended operating temperature range in the SFH 4258-Z?

A: The SFH 4258-Z operates from -40°C to 100°C compared to the SFH 4451 range of -40°C to 85°C. This extended upper temperature limit provides additional thermal margin for applications operating in elevated ambient conditions.

Q: Does the package change from 2-SMD to 4-PLCC affect electrical performance?

A: Package form factor does not alter electrical performance. Both configurations are surface mount technologies. The 4-PLCC package provides different mechanical and thermal characteristics that must be accommodated in circuit board design.