FND327C 7-Segment LED Display - Equivalent & Substitute Parts

Part Overview

The FND327C is a single-character, 0.36-inch red 7-segment LED display manufactured by onsemi in a 10-DIP package configuration. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and production continuity. The display operates as a common cathode device with a forward voltage of 1.8V and test current of 20mA, suitable for numeric and alphanumeric display applications in legacy and modern circuit designs.

Substiute Parts

FND327C

onsemiIn Stock: 842FND327C Datasheet

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LDS-C324RI

Lumex Opto/Components Inc.In Stock: 1255LDS-C324RI Datasheet

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LDS-C325RI

Lumex Opto/Components Inc.In Stock: 845LDS-C325RI Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FND327C are qualified based on the following critical parameters that determine functional and mechanical compatibility:

Primary Compatibility Criteria:

• Display type: 7-Segment LED (single character)
• Common pin configuration: Common Cathode
• Color: Red
• Package type: 10-DIP (0.200", 5.08mm)
• Digit size: 0.36" (9.14mm)
• Physical envelope: Compatible with 0.551" H x 0.299-0.295" W x 0.335" D dimensions

Electrical Operating Parameters:

• Forward voltage (Vf): 1.8V to 2V range
• Test current: 10mA to 20mA range
• Millicandela rating: 0.5mcd to 4.6mcd range
• Wavelength: 635nm to 700nm (red spectrum)
• Power dissipation: 100mW to 105mW

The substitute parts LDS-C324RI and LDS-C325RI from Lumex Opto/Components Inc. meet these criteria with minor variations in electrical characteristics within acceptable operating ranges for common cathode 7-segment display applications.

Parameter Comparison

Engineering Selection Recommendations

LDS-C324RI Selection Criteria: The LDS-C324RI is an active product with ROHS3 compliance, making it suitable for new designs requiring regulatory adherence. The 0.2V increase in forward voltage (2V vs. 1.8V) and reduced test current (10mA vs. 20mA) result in lower power dissipation while maintaining comparable brightness at 4.6mcd. The 635nm wavelength produces a brighter red appearance compared to the FND327C's 660nm. This substitute is appropriate for applications where power efficiency and modern compliance certifications are required.

LDS-C325RI Selection Criteria: The LDS-C325RI is also an active product with ROHS3 compliance. This part features a significantly lower millicandela rating (0.5mcd vs. 3mcd), making it suitable only for applications where reduced brightness is acceptable or preferred. The 700nm wavelength produces a deeper red color. This substitute should be selected only when lower luminous intensity is a design requirement.

Product Status Consideration: Both substitute parts are active products, ensuring long-term availability and supply chain stability compared to the obsolete FND327C. Selection between LDS-C324RI and LDS-C325RI depends on brightness requirements and wavelength preference for the specific application.

Frequently Asked Questions (FAQ)

Q: Can the LDS-C324RI directly replace the FND327C in existing designs? A: The LDS-C324RI is mechanically and electrically compatible with the FND327C. Both use 10-DIP packaging, common cathode configuration, and operate within compatible voltage and current ranges. The 0.2V forward voltage difference and reduced test current are within acceptable operating margins for most 7-segment display applications. Circuit design review is recommended to confirm compatibility with existing current-limiting resistor values.

Q: What is the difference between LDS-C324RI and LDS-C325RI? A: The primary difference is brightness. The LDS-C324RI provides 4.6mcd (comparable to the FND327C at 3mcd), while the LDS-C325RI provides only 0.5mcd. Additionally, the wavelengths differ: LDS-C324RI at 635nm produces a brighter red, and LDS-C325RI at 700nm produces a deeper red. Select based on brightness and color requirements.

Q: Are the physical dimensions identical between all three parts? A: The dimensions are nearly identical. The FND327C measures 0.551" H x 0.299" W x 0.335" D, while both Lumex substitutes measure 0.551" H x 0.295" W x 0.335" D. The 0.004" (0.1mm) width difference is negligible for PCB layout and mechanical mounting purposes.

Q: Do the substitute parts meet modern compliance requirements? A: Yes. Both LDS-C324RI and LDS-C325RI are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory standards. The FND327C, being obsolete, does not specify RoHS compliance.

Q: How do I adjust circuit design when switching from FND327C to LDS-C324RI? A: The forward voltage increases from 1.8V to 2V, and test current decreases from 20mA to 10mA. Recalculate current-limiting resistor values using Ohm's law: R = (Supply Voltage - Vf) / I. For example, with a 5V supply: FND327C requires R = (5V - 1.8V) / 20mA = 160Ω; LDS-C324RI requires R = (5V - 2V) / 10mA = 300Ω. Verify that the new resistor value does not exceed the maximum power dissipation rating of 105mW.

Q: What is the packaging difference between the parts? A: All three parts use 10-DIP (0.200", 5.08mm) package type, ensuring identical PCB footprint compatibility. The FND327C and LDS-C325RI do not specify packaging format in the data, while LDS-C324RI is supplied in tube packaging. This does not affect electrical or mechanical compatibility.