LTL-403Y Equivalent & Substitute Parts

Part Overview

The LTL-403Y is an active yellow diffused through-hole LED manufactured by Lite-On Inc., designed for indication applications with a dominant wavelength of 588nm. This component is specified for 2.1V forward voltage operation at 10mA test current, housed in a rectangular radial package with 4.00mm x 2.00mm lens dimensions. The part maintains ROHS3 compliance and unlimited moisture sensitivity rating (MSL 1), making it suitable for standard industrial and consumer electronics applications. Substitute parts may be required due to inventory constraints, manufacturing discontinuation, or design optimization needs while maintaining functional equivalence.

Substiute Parts

LTL-403Y

Lite-On Inc.In Stock: 1040LTL-403Y Datasheet

Current PartRFQ

WP144YDT

KingbrightIn Stock: 2117WP144YDT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The WP144YDT from Kingbright qualifies as a direct substitute for the LTL-403Y based on the following critical parameters:

• Color Match: Both parts are yellow LEDs
• Wavelength Alignment: Dominant wavelength 588nm (LTL-403Y) and 588nm (WP144YDT) are identical
• Forward Voltage: Both specified at 2.1V typical, ensuring circuit compatibility
• Lens Configuration: Both feature diffused rectangular lenses with flat tops
• Mounting Technology: Both are through-hole radial packages
• Compliance: Both maintain ROHS3 compliance and MSL 1 rating
• Mechanical Fit: Lens dimensions (4.00mm x 2.00mm for LTL-403Y; 3.90mm x 1.90mm for WP144YDT) and maximum height (7.00mm) are compatible with standard PCB layouts

Substitution is valid for applications where the specified electrical and mechanical parameters are the primary selection criteria.

Parameter Comparison

Engineering Selection Recommendations

Both the LTL-403Y and WP144YDT are active products with full ROHS3 compliance and MSL 1 ratings, qualifying them for equivalent use in indication circuits. The primary electrical parameters—forward voltage (2.1V) and dominant wavelength (588nm)—are matched across both parts, ensuring functional interchangeability in standard LED indication applications.

The WP144YDT exhibits higher luminous intensity (4mcd versus 2.5mcd) and operates at a higher test current (20mA versus 10mA), making it suitable for applications requiring increased brightness. The slightly wider viewing angle (110° versus 104°) provides marginally improved light distribution. Mechanical dimensions are within acceptable tolerance for standard through-hole PCB layouts.

Selection between these parts should be based on circuit current budget, brightness requirements, and inventory availability. Both parts satisfy the core functional and compliance requirements for yellow LED indication in industrial and consumer applications.

Frequently Asked Questions (FAQ)

Q: Can WP144YDT replace LTL-403Y in existing designs without circuit modification?

A: Yes, for standard indication applications. Both parts share identical forward voltage (2.1V) and dominant wavelength (588nm). The WP144YDT's higher brightness (4mcd) and wider viewing angle (110°) are compatible with existing circuits. No circuit changes are required if the application can accommodate the higher test current specification (20mA versus 10mA).

Q: Are the mechanical dimensions compatible?

A: Yes. Both parts feature rectangular radial packages with 7.00mm maximum height. Lens dimensions differ slightly (4.00mm x 2.00mm for LTL-403Y; 3.90mm x 1.90mm for WP144YDT), but both fit standard through-hole PCB layouts designed for rectangular LEDs in this size class.

Q: Do both parts meet the same compliance standards?

A: Yes. Both LTL-403Y and WP144YDT are ROHS3 compliant with MSL 1 (unlimited moisture sensitivity), meeting identical environmental and regulatory requirements for industrial and consumer applications.

Q: What is the difference in brightness between these parts?

A: The WP144YDT provides 4mcd compared to the LTL-403Y's 2.5mcd at their respective test currents. This represents a higher luminous intensity suitable for applications requiring increased visibility.

Q: Are there any wavelength differences that affect color perception?

A: Both parts have identical dominant wavelengths (588nm), ensuring consistent yellow color perception. Peak wavelengths differ slightly (585nm for LTL-403Y; 590nm for WP144YDT), but this variation is within the standard yellow LED spectrum and does not affect practical color matching in indication applications.