LTST-C171CWRT Equivalent & Substitute Parts

Part Overview

The LTST-C171CWRT is a red diffused LED in 0805 (2012 Metric) surface mount package manufactured by Lite-On Inc. This component is designed for LED indication applications with a dominant wavelength of 645nm and a forward voltage of 1.8V at 20mA test current. The part is currently classified as obsolete, necessitating identification of active equivalent alternatives that maintain functional compatibility for new designs and production continuity.

Substiute Parts

LTST-C171CWRT

Lite-On Inc.In Stock: 971LTST-C171CWRT Datasheet

Current PartRFQ

LTST-C171KDWT

Lite-On Inc.In Stock: 1174LTST-C171KDWT Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LTST-C171CWRT is determined by strict alignment of the following critical parameters:

Package and Mechanical Compatibility:

• Package / Case: 0805 (2012 Metric)
• Mounting Type: Surface Mount
• Size / Dimension: 2.00mm L x 1.30mm W
• Height (Max): 0.90mm
• Lens Style: Rectangle with Flat Top
• Lens Size: 1.40mm x 1.25mm

Optical and Functional Compatibility:

• Color: Red
• Lens Transparency: Diffused
• Lens Color: White
• Viewing Angle: 130°

Electrical Operating Parameters:

• Current - Test: 20mA
• Voltage - Forward (Vf) (Typ): Within acceptable tolerance range
• Millicandela Rating: Within acceptable tolerance range
• Wavelength - Dominant: Red spectrum (638nm to 645nm range)

Compliance and Environmental:

• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level (MSL): 3 (168 Hours)
• REACH Status: REACH Unaffected

Substitute parts must match all mechanical and package specifications, maintain red color indication with diffused lens characteristics, operate within the specified electrical parameters, and maintain equivalent compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

The LTST-C171KDWT is an active equivalent substitute for the obsolete LTST-C171CWRT. Both components are manufactured by Lite-On Inc. and share identical mechanical, optical, and package specifications. The substitute part maintains full compatibility with existing PCB layouts and assembly processes.

Compliance Status: Both parts are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic component manufacturing and distribution.

Electrical Characteristics: The LTST-C171KDWT operates at 2V forward voltage compared to the main part's 1.8V. The millicandela rating of 24.75mcd is equivalent to the main part's 25mcd specification. The dominant wavelength shifts from 645nm to 638nm, remaining within the red spectrum for indication applications. Both parts operate at identical 20mA test current.

Product Status: The LTST-C171KDWT is classified as active, ensuring continued availability and supply chain stability for new production and design implementations.

Frequently Asked Questions (FAQ)

Q: Can the LTST-C171KDWT be used as a direct replacement for the LTST-C171CWRT in existing designs?

A: Yes. Both parts share identical package specifications (0805 / 2012 Metric), mounting type (surface mount), mechanical dimensions, and optical characteristics (red diffused lens with white color). The forward voltage difference of 0.2V (1.8V to 2V) and wavelength shift from 645nm to 638nm are within acceptable tolerance for red LED indication applications.

Q: What is the primary reason for substitution?

A: The LTST-C171CWRT is classified as obsolete. The LTST-C171KDWT is an active product from the same manufacturer, ensuring supply availability and production continuity.

Q: Are there any compliance differences between the two parts?

A: No. Both parts maintain identical RoHS3 compliance status and REACH unaffected classification. Moisture sensitivity level (MSL 3, 168 Hours) is equivalent for both components.

Q: How does the wavelength difference affect application performance?

A: The dominant wavelength shifts from 645nm to 638nm, representing a 7nm difference within the red spectrum. Both wavelengths are suitable for standard red LED indication applications. The peak wavelength shifts from 660nm to 650nm correspondingly.

Q: Are the optical characteristics identical?

A: Yes. Both parts feature diffused lens transparency, white lens color, rectangle flat-top lens style, identical lens dimensions (1.40mm x 1.25mm), and equivalent 130° viewing angle.

Q: What is the impact of the forward voltage increase from 1.8V to 2V?

A: Circuit designs must accommodate the 0.2V increase in forward voltage. This affects series resistor calculations and power supply margin requirements. Existing designs operating at 1.8V forward voltage require circuit verification before implementation.

Q: Are the mechanical dimensions identical?

A: Yes. Both parts share identical dimensions: 2.00mm length, 1.30mm width, and 0.90mm maximum height. PCB footprints and assembly processes require no modification.

Q: Is the millicandela rating difference significant?

A: The difference between 25mcd and 24.75mcd is 0.25mcd, representing a 1% variation. This is negligible for standard indication applications.