HSDL-4420 Equivalent & Substitute Parts

Part Overview

The HSDL-4420 is an infrared (IR) emitter manufactured by Lite-On Inc., designed for applications requiring 875nm wavelength emission at 100mA forward current. This component operates at a typical forward voltage of 1.5V and delivers 9mW/sr radiant intensity at 50mA. The device features a 24° viewing angle and is housed in an axial through-hole package suitable for PCB integration.

The HSDL-4420 is classified as obsolete. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or repair requirements for systems utilizing this component.

Substiute Parts

HSDL-4420

Lite-On Inc.In Stock: 4590HSDL-4420 Datasheet

Current PartRFQ

IR91-21C

Everlight Electronics Co LtdIn Stock: 20124IR91-21C Datasheet

MFR RecommendedRFQ

IR95-21C/TR9

Everlight Electronics Co LtdIn Stock: 816IR95-21C/TR9 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the HSDL-4420 are identified based on the following electrical and mechanical compatibility criteria:

Primary Substitution Parameters:

• Type: Infrared (IR) Emitter
• Mounting Type: Through Hole or Surface Mount (design-dependent)
• Package / Case: Axial or equivalent form factor
• Operating Temperature Range: Must encompass or match the original specification
• RoHS Compliance: ROHS3 Compliant status maintained
• Wavelength: 875nm or 940nm (near-infrared spectrum, application-dependent)
• Current Rating: Forward current capacity suitable for circuit design
• Voltage Rating: Forward voltage compatible with power supply constraints

The substitute parts identified—IR91-21C and IR95-21C/TR9—are both manufactured by Everlight Electronics Co Ltd and maintain active product status. Both substitutes operate at 940nm wavelength with 65mA maximum forward current and 1.2V typical forward voltage. These parameters fall within acceptable tolerance ranges for IR emitter applications where the original 875nm specification can accommodate the longer wavelength characteristic of 940nm devices.

Parameter Comparison

Engineering Selection Recommendations

IR91-21C Selection Criteria: The IR91-21C is recommended for through-hole PCB designs requiring direct pin-for-pin or footprint-compatible replacement of the HSDL-4420. This substitute maintains through-hole mounting and axial package geometry, enabling mechanical compatibility with existing PCB layouts. The IR91-21C carries active product status and ROHS3 compliance, ensuring long-term supply chain availability and regulatory alignment. The operating temperature range (-25°C to 85°C) is narrower than the original specification; applications requiring operation below -25°C must be evaluated against specific system requirements.

IR95-21C/TR9 Selection Criteria: The IR95-21C/TR9 is suitable for surface-mount PCB designs or new designs where SMD technology is preferred. This substitute provides active product status and operates across the full temperature range (-40°C to 85°C) matching the original specification. The 2-SMD, Yoke Bend package requires PCB layout redesign and is not mechanically compatible with through-hole footprints. RoHS compliance status for this part is not specified in available documentation.

Both substitutes are manufactured by Everlight Electronics Co Ltd, an established supplier of infrared emitter components, and maintain HTSUS classification 8541.41.0000 consistent with the original part.

Frequently Asked Questions (FAQ)

Q: Can IR91-21C directly replace HSDL-4420 in existing PCB designs? A: IR91-21C maintains through-hole axial package geometry compatible with HSDL-4420 footprints. Electrical parameter differences (65mA vs. 100mA forward current, 1.2V vs. 1.5V forward voltage, 940nm vs. 875nm wavelength) require circuit design review to confirm compatibility with existing current-limiting resistors and optical system requirements.

Q: What is the primary difference between IR91-21C and IR95-21C/TR9? A: IR91-21C is a through-hole axial component suitable for existing through-hole PCB designs. IR95-21C/TR9 is a surface-mount 2-SMD component requiring PCB layout redesign. Both operate at 940nm wavelength and 65mA maximum forward current.

Q: Does the 940nm wavelength of substitute parts affect system performance compared to the original 875nm? A: Wavelength difference between 875nm and 940nm represents a shift within the near-infrared spectrum. System compatibility depends on optical receiver sensitivity, filter characteristics, and application-specific requirements. Circuit design review is necessary to confirm performance equivalence.

Q: Are both substitute parts RoHS compliant? A: IR91-21C is ROHS3 compliant. RoHS compliance status for IR95-21C/TR9 is not specified in available technical documentation.

Q: What is the operating temperature limitation of IR91-21C? A: IR91-21C operates from -25°C to 85°C, which is narrower than the original HSDL-4420 specification of -40°C to 85°C. Applications requiring operation below -25°C must use IR95-21C/TR9 (-40°C to 85°C) or evaluate alternative solutions.

Q: How do forward current ratings affect circuit design when substituting parts? A: The HSDL-4420 supports 100mA maximum forward current, while both substitutes support 65mA maximum. Existing current-limiting resistor values must be recalculated to ensure forward current does not exceed 65mA in substitute applications. Lower forward current may reduce radiant intensity output.