HSMS-C660 Red LED SMD Right Angle Equivalent & Substitute Parts

Part Overview

The HSMS-C660 is a red diffused LED chip designed for surface mount right angle applications, manufactured by Broadcom Limited. This component features a 626nm dominant wavelength with 5mcd brightness rating and operates at 1.9V forward voltage. The product is currently obsolete, making identification of compatible substitute parts essential for ongoing design support and production continuity. Equivalent parts must maintain compatibility across electrical characteristics, mechanical dimensions, and mounting configuration while accounting for variations in lens transparency and brightness specifications.

Substiute Parts

HSMS-C660

Broadcom LimitedIn Stock: 963HSMS-C660 Datasheet

Current PartRFQ

HSMS-C680

Broadcom LimitedIn Stock: 43198HSMS-C680 Datasheet

DirectRFQ

LTST-S321KRKT

Lite-On Inc.In Stock: 12709LTST-S321KRKT Datasheet

MFR RecommendedRFQ

QTLP610C2TR

onsemiIn Stock: 2871QTLP610C2TR Datasheet

MFR RecommendedRFQ

QTLP610C7TR

onsemiIn Stock: 1205QTLP610C7TR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the HSMS-C660 is determined by the following critical parameters:

Mandatory Compatibility Criteria:

• Mounting Type: Surface Mount, Right Angle (all substitutes must match)
• Package / Case: 2-SMD, No Lead (all substitutes must match)
• Color: Red (all substitutes must match)
• Current - Test: 20mA (all substitutes must match)
• Lens Size: 2.00mm x 1.00mm (all substitutes must match)

Allowable Variation Parameters:

• Voltage - Forward (Vf): Range 1.9V to 2.0V acceptable
• Wavelength - Dominant: Range 621nm to 645nm acceptable (red spectrum)
• Millicandela Rating: 5mcd to 54mcd acceptable (brightness variation permitted)
• Lens Transparency: Diffused or Clear (both acceptable for indication applications)
• Height (Max): 1.00mm to 1.10mm acceptable
• Moisture Sensitivity Level (MSL): 2A to 3 acceptable

The four substitute parts listed below meet all mandatory criteria and fall within allowable variation ranges for electrical and optical characteristics.

Parameter Comparison

Engineering Selection Recommendations

HSMS-C680 (Broadcom Limited) is the primary direct substitute. This part maintains Broadcom manufacturer continuity and shares identical electrical test current and forward voltage characteristics within acceptable tolerance. The lens transparency differs (clear vs. diffused), which affects light distribution but does not impact electrical compatibility. Product status is active with current inventory availability. RoHS3 compliance provides regulatory alignment for new designs.

LTST-S321KRKT (Lite-On Inc.) offers the highest brightness rating at 54mcd, providing enhanced visibility compared to the original 5mcd specification. Forward voltage and test current remain compatible. This part is actively manufactured with substantial inventory. RoHS3 compliance is confirmed. The increased brightness may require circuit-level current limiting adjustment if the original design relied on the lower 5mcd output.

QTLP610C2TR (onsemi) provides a close electrical match with 2V forward voltage and 7mcd brightness. Wavelength at 630nm remains within the red spectrum range. Product status is obsolete but inventory is available. Moisture sensitivity level is superior (MSL 1 vs. MSL 2A). Height specification is 1.10mm maximum, representing a 0.10mm increase from the original.

QTLP610C7TR (onsemi) matches the original 1.9V forward voltage exactly and provides 20mcd brightness. Wavelength at 645nm is at the far red spectrum boundary. Product status is obsolete with limited inventory. Moisture sensitivity level is superior (MSL 1). Height specification is 1.10mm maximum. This part is suitable for applications where forward voltage matching is critical.

Frequently Asked Questions (FAQ)

Q: Can HSMS-C680 be used as a direct replacement for HSMS-C660?

A: Yes. Both parts share identical mounting type, package configuration, test current, and lens size. The primary difference is lens transparency (clear vs. diffused), which affects light distribution pattern but maintains electrical compatibility. HSMS-C680 is actively manufactured, making it the preferred substitute for production continuity.

Q: What is the impact of using a higher brightness LED such as LTST-S321KRKT (54mcd vs. 5mcd)?

A: The substitute provides significantly higher luminous intensity. Circuit-level current limiting may require adjustment to prevent over-brightness or excessive power consumption. Verify that the application's optical design can accommodate the increased light output without causing glare or unintended visual effects.

Q: Are there differences in moisture sensitivity between substitute parts?

A: Yes. HSMS-C660 and HSMS-C680 specify MSL 2A (4 weeks), while LTST-S321KRKT specifies MSL 3 (168 hours), and both onsemi parts specify MSL 1 (unlimited). Lower MSL ratings indicate greater tolerance to moisture exposure during storage and handling. Select based on your supply chain storage conditions and manufacturing environment.

Q: Does lens transparency (diffused vs. clear) affect electrical performance?

A: No. Lens transparency is an optical characteristic that affects light distribution and viewing angle but does not impact electrical parameters such as forward voltage, test current, or wavelength. Selection should be based on the application's optical requirements.

Q: Can QTLP610C7TR be used if forward voltage matching is critical?

A: Yes. QTLP610C7TR maintains the original 1.9V forward voltage specification, making it suitable for designs where voltage matching is essential. However, the part is obsolete with limited inventory. Verify availability before committing to this substitute in production designs.

Q: What are the dimensional constraints for PCB layout?

A: All substitute parts maintain the 2.00mm x 1.00mm lens size and 3.00mm length specification. Height varies slightly: HSMS-C660, HSMS-C680, and LTST-S321KRKT are 1.00mm maximum, while QTLP610C2TR and QTLP610C7TR are 1.10mm maximum. Verify that your PCB clearance accommodates the 0.10mm height difference if using onsemi parts.

Q: Are all substitute parts RoHS compliant?

A: Broadcom (HSMS-C680) and Lite-On (LTST-S321KRKT) parts are confirmed ROHS3 compliant. onsemi parts (QTLP610C2TR and QTLP610C7TR) do not specify RoHS status in the provided data. Confirm RoHS compliance requirements with your regulatory or procurement team before final selection.