WP56BYD Yellow Diffused LED T-1 3/4 Through Hole - Equivalent & Substitute Parts

Part Overview

The WP56BYD is a yellow diffused LED indicator manufactured by Kingbright, designed for through-hole mounting applications. This component features a 5mm T-1 3/4 form factor with a flashing capability, operating at 14V forward voltage with a dominant wavelength of 588nm. The part is currently active in production with RoHS3 compliance and unlimited moisture sensitivity rating (MSL 1).

Substitute parts are necessary when the WP56BYD becomes unavailable, when alternative packaging formats are required, or when circuit design modifications necessitate different electrical characteristics such as forward voltage or current ratings.

Key Parameters

Parameter	WP56BYD Value	Significance for Substitution
Color	Yellow	Visual indication color must match application requirements
Lens Transparency	Diffused	Determines light distribution pattern and visibility angle
Lens Size / Form Factor	5mm, T-1 3/4	Physical compatibility with PCB mounting holes and mechanical clearance
Voltage - Forward (Vf) Typical	14V	Critical for circuit design; determines series resistor requirements
Wavelength - Dominant	588nm	Defines color specification within yellow spectrum
Millicandela Rating	20mcd	Brightness level; affects visibility in different lighting conditions
Viewing Angle	60°	Determines angular visibility range for indication purposes
Mounting Type	Through Hole, Radial	PCB assembly method compatibility
Features	Flashing	Built-in flashing capability; not all substitutes include this feature
Lens Style	Round with Domed Top	Physical appearance and light focusing characteristics

Substitute Part Grouping Explanation

Substitution logic for the WP56BYD is based on the following allowed parameters:

Primary Compatibility Criteria:

Color: Yellow (all substitutes must be yellow)
Lens Transparency: Diffused (maintains consistent light distribution)
Mounting Type: Through Hole, Radial (ensures PCB compatibility)
Lens Style: Round with Domed Top (physical form factor match)
Lens Size: 5mm, T-1 3/4 (mechanical fit in existing PCB holes)

Secondary Compatibility Criteria:

Wavelength - Dominant: 588nm to 590nm range (yellow spectrum consistency)
Viewing Angle: 50° to 60° (acceptable visibility range variation)
RoHS3 Compliance: All substitutes must maintain regulatory compliance
Moisture Sensitivity Level: MSL 1 (Unlimited) for storage compatibility

Electrical Parameter Flexibility:

Voltage - Forward (Vf): Substitutes range from 1.8V to 12V; circuit design must accommodate selected voltage
Millicandela Rating: Ranges from 2.1mcd to 29mcd; brightness variation acceptable based on application requirements
Current - Test: Varies by part; must be verified against circuit design

Feature Consideration:

The WP56BYD includes flashing capability; most substitutes do not include this feature and are standard continuous-operation LEDs

Parameter Comparison

Part Number	Manufacturer	Color	Lens Transparency	Lens Size	Vf (Typ)	Wavelength - Dominant	mcd Rating	Viewing Angle	Mounting Type	Features	Product Status
WP56BYD	Kingbright	Yellow	Diffused	5mm, T-1 3/4	14V	588nm	20mcd	60°	Through Hole, Radial	Flashing	Active
5219673F	Dialight	Yellow	Diffused	4.75mm Dia	2.1V	588nm	12.6mcd	60°	Through Hole, Radial	—	Active
HLMP-3401	Broadcom Limited	Yellow	Diffused	5mm, T-1 3/4	2V	585nm	5.7mcd	60°	Through Hole, Radial	—	Active
HLMP-3401-E0002	Broadcom Limited	Yellow	Diffused	5mm, T-1 3/4	2V	585nm	5.7mcd	60°	Through Hole, Radial	—	Active
HLMP-3401-E00B2	Broadcom Limited	Yellow	Diffused, Tinted	5mm	2V	583nm	5.7mcd	—	Through Hole, Right Angle	—	Active
HLMP-3651	Broadcom Limited	Yellow	Diffused	5mm, T-1 3/4	12V	585nm	2.2mcd	60°	Through Hole, Radial	—	Active
HLMP-4719	Broadcom Limited	Yellow	Diffused	5mm, T-1 3/4	1.8V	585nm	2.1mcd	50°	Through Hole, Radial	—	Active
HLMP-4719-A0002	Broadcom Limited	Yellow	Diffused	5mm, T-1 3/4	1.8V	585nm	2.1mcd	50°	Through Hole, Radial	—	Active
HLMP-D401	Broadcom Limited	Orange	Diffused	5mm, T-1 3/4	1.9V	602nm	5.4mcd	60°	Through Hole, Radial	—	Active
LTL-307Y	Lite-On Inc.	Yellow	Diffused	5.00mm Dia	2.1V	590nm	29mcd	50°	Through Hole, Radial	—	Active
MV5354A	onsemi	Yellow	Diffused	5mm, T-1 3/4	2.1V	—	25mcd	24°	Through Hole, Radial	—	Obsolete

Engineering Selection Recommendations

Recommended Primary Substitutes (Active Status, Full Compatibility):

HLMP-3651 (Broadcom Limited) is the closest electrical match for high-voltage applications. This part operates at 12V forward voltage, requiring minimal circuit redesign compared to the WP56BYD's 14V specification. It maintains the identical 5mm T-1 3/4 form factor, diffused yellow lens, and 60° viewing angle. RoHS3 compliance and MSL 1 rating ensure regulatory and storage compatibility. The 2.2mcd brightness is lower than the WP56BYD's 20mcd; circuit design must verify this brightness reduction is acceptable for the application.

HLMP-3401 and HLMP-3401-E0002 (Broadcom Limited) provide standard yellow LED operation at 2V forward voltage. Both parts share identical electrical and optical specifications with the primary difference being packaging format (Bulk versus Cut Tape). These parts require significant circuit redesign due to the 12V voltage reduction from the WP56BYD. The 5.7mcd brightness is substantially lower. Selection is appropriate only when circuit design accommodates low-voltage operation and reduced brightness requirements.

LTL-307Y (Lite-On Inc.) operates at 2.1V with the highest brightness rating (29mcd) among substitutes. The 5mm form factor and diffused yellow lens provide mechanical compatibility. The 50° viewing angle represents a minor reduction from the WP56BYD's 60°. This part is suitable for applications prioritizing brightness over voltage compatibility.

Secondary Substitutes (Conditional Use):

HLMP-4719 and HLMP-4719-A0002 (Broadcom Limited) operate at the lowest forward voltage (1.8V) and are suitable for low-power circuit designs. The 50° viewing angle and 2.1mcd brightness represent significant reductions from the WP56BYD specification. Packaging difference (Bulk versus Cut Tape) allows format selection based on assembly requirements.

5219673F (Dialight) provides a 2.1V alternative with 12.6mcd brightness. The 4.75mm lens diameter represents a minor mechanical variation from the standard 5mm specification; verify PCB hole compatibility before selection.

Not Recommended:

HLMP-D401 (Broadcom Limited) is orange-colored (602nm dominant wavelength) rather than yellow. This part does not meet the color specification requirement and is not a functional substitute for yellow indication applications.

MV5354A (onsemi) carries obsolete product status. While specifications are compatible, obsolete parts present supply chain risk and should not be selected for new designs or long-term production requirements.

HLMP-3401-E00B2 (Broadcom Limited) features right-angle mounting configuration, incompatible with standard radial through-hole PCB layouts designed for the WP56BYD.

Feature Consideration:

The WP56BYD includes built-in flashing capability. No substitute parts in this list include flashing features. Applications requiring flashing operation must either retain the WP56BYD or implement external flashing circuitry with a standard LED substitute.

Frequently Asked Questions (FAQ)

Q: Can HLMP-3651 directly replace WP56BYD without circuit modification?

A: HLMP-3651 requires circuit redesign due to the 2V voltage difference (12V versus 14V forward voltage). The series resistor value must be recalculated to accommodate the lower voltage drop. Brightness reduction from 20mcd to 2.2mcd must be verified as acceptable for the application. Mechanical form factor and lens characteristics are compatible.

Q: Why is HLMP-D401 listed if it is orange, not yellow?

A: HLMP-D401 is included in the reference data as a documented substitute in the WP56BYD specification sheet. However, it does not meet the yellow color requirement and is not functionally equivalent for yellow indication applications. It is listed for completeness and to clarify why it is not recommended.

Q: What is the difference between HLMP-3401 and HLMP-3401-E0002?

A: Both parts have identical electrical and optical specifications. The difference is packaging format: HLMP-3401 is supplied in Bulk packaging, while HLMP-3401-E0002 is supplied in Cut Tape (CT) format. Selection depends on assembly process requirements and volume needs.

Q: Can I use LTL-307Y if brightness is critical to my application?

A: Yes. LTL-307Y provides the highest brightness among substitutes at 29mcd, compared to the WP56BYD's 20mcd. The 2.1V forward voltage requires circuit redesign. The 50° viewing angle is slightly narrower than the WP56BYD's 60°. Verify that the reduced viewing angle does not impact application visibility requirements.

Q: Does the 4.75mm lens diameter of 5219673F affect PCB compatibility?

A: The 4.75mm diameter is slightly smaller than the standard 5mm specification. Verify that existing PCB mounting holes accommodate this dimension. If PCB holes are precisely sized for 5mm components, the 5219673F may not fit securely. Contact the PCB manufacturer to confirm hole tolerance specifications.

Q: Why do most substitutes have lower brightness than the WP56BYD?

A: The WP56BYD operates at 14V forward voltage with a 20mcd brightness rating. Most substitutes operate at significantly lower voltages (1.8V to 2.1V), which reduces available power and brightness output. Higher-voltage alternatives like HLMP-3651 (12V) maintain closer brightness levels but still operate below the WP56BYD specification.

Q: Is the flashing feature available in any substitute?

A: No substitute parts in this reference list include built-in flashing capability. The WP56BYD's flashing feature is a specialized characteristic. To maintain flashing operation, either retain the WP56BYD or implement external flashing circuitry using a standard LED substitute.

Q: Are all substitutes RoHS3 compliant?

A: Yes. All recommended substitute parts carry RoHS3 compliance certification, matching the WP56BYD's regulatory status. Compliance documentation is available from manufacturers upon request.

Q: What is the significance of MSL 1 (Unlimited) rating?

A: MSL 1 indicates unlimited shelf life under standard storage conditions. All parts in this reference list carry MSL 1 rating, ensuring compatibility with standard component storage and handling procedures without special moisture control requirements.

Q: Can I use MV5354A as a substitute despite its obsolete status?

A: MV5354A is not recommended for new designs or long-term production. Obsolete parts present supply chain risk, limited availability, and potential manufacturing discontinuation. Current inventory (977 pcs) may be insufficient for production requirements. Select from active-status alternatives instead.

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