SD3421-002 Equivalent & Substitute Parts Reference

Part Overview

The SD3421-002 is a photodiode optical sensor manufactured by Honeywell Sensing and Productivity Solutions, packaged in TO46 flat pack configuration. This component features a 15 nanosecond response time and 90-degree viewing angle, designed for photodiode applications requiring PIN diode technology. The product is classified as obsolete, necessitating identification of active equivalent components to maintain design continuity and ensure supply chain availability for new production and field replacements.

Substiute Parts

SD3421-002

Honeywell Sensing and Productivity SolutionsIn Stock: 1201SD3421-002 Datasheet

Current PartRFQ

100-11-21-221

Advanced PhotonixIn Stock: 1298100-11-21-221 Datasheet

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OP913WSL

TT Electronics/Optek TechnologyIn Stock: 884OP913WSL Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the SD3421-002 is determined by the following critical parameters that must align across candidate parts:

Primary Substitution Criteria:

• Diode Type: PIN (mandatory match)
• Mounting Type: Through Hole (mandatory match)
• Voltage - DC Reverse (Vr) Max: 75 V or greater (minimum requirement)
• Operating Temperature Range: Must encompass or exceed -55°C to 125°C
• Moisture Sensitivity Level: 1 (Unlimited) preferred for equivalent reliability
• RoHS Compliance: ROHS3 or equivalent compliance required

Secondary Compatibility Parameters:

• Response Time: 15 ns or faster (equal or superior performance)
• Viewing Angle: 90° preferred; 60° acceptable with application verification
• Current - Dark (Typ): Lower values preferred for reduced noise

The substitute parts listed below satisfy the primary substitution criteria and maintain functional equivalence within the specified parameter constraints.

Parameter Comparison

Engineering Selection Recommendations

100-11-21-221 (Advanced Photonix)

This component is the primary substitute for SD3421-002. It meets all mandatory substitution criteria: PIN diode type, through-hole mounting, 75 V reverse voltage rating, and ROHS3 compliance. The 13 nanosecond response time exceeds the original 15 nanosecond specification, providing superior performance. The 90-degree viewing angle matches the original specification exactly. The operating temperature range of -40°C to 125°C covers the upper portion of the original range; applications requiring operation below -40°C require verification. The 1.6 nanoampere dark current is significantly lower than the original 20 nanoampere specification, reducing noise characteristics. Active product status ensures ongoing availability and supply chain continuity.

OP913WSL (TT Electronics/Optek Technology)

This component satisfies the PIN diode type, through-hole mounting, and ROHS3 compliance requirements. However, the 32 V maximum reverse voltage rating is substantially below the 75 V specification of the original part, limiting its application scope to circuits operating at lower bias voltages. The 60-degree viewing angle is narrower than the original 90-degree specification and may not be suitable for applications requiring wider field-of-view detection. The extended operating temperature range of -65°C to 125°C provides additional low-temperature capability. Response time is not specified for this component. Active product status supports supply availability. Selection of this component requires confirmation that the reduced voltage rating and narrower viewing angle are compatible with the target application.

Frequently Asked Questions (FAQ)

Q: Can 100-11-21-221 be used as a direct replacement for SD3421-002?

A: Yes, 100-11-21-221 meets all primary substitution criteria. It provides equivalent or superior electrical performance with matching 75 V reverse voltage rating, 90-degree viewing angle, and through-hole mounting. The operating temperature range of -40°C to 125°C covers the upper portion of the original specification; applications requiring operation below -40°C require verification of compatibility.

Q: What is the key limitation of OP913WSL as a substitute?

A: The OP913WSL has a maximum reverse voltage rating of 32 V, which is significantly lower than the 75 V requirement of SD3421-002. This component is suitable only for applications operating at lower bias voltages. Additionally, the 60-degree viewing angle is narrower than the original 90-degree specification.

Q: Are both substitute parts RoHS compliant?

A: Yes, both 100-11-21-221 and OP913WSL are ROHS3 compliant, meeting current regulatory requirements for hazardous substance restrictions.

Q: What is the difference in dark current between the main part and substitutes?

A: The SD3421-002 has a typical dark current of 20 nanoamperes. The 100-11-21-221 has 1.6 nanoamperes (significantly lower, reducing noise), while the OP913WSL has 25 nanoamperes (slightly higher). Lower dark current generally improves signal-to-noise ratio in photodiode applications.

Q: Does response time differ between the parts?

A: The SD3421-002 specifies 15 nanoseconds response time. The 100-11-21-221 specifies 13 nanoseconds (faster, superior performance). The OP913WSL does not provide response time specification in the available data.

Q: Are there package or pinout differences between these components?

A: The SD3421-002 uses TO46 flat pack configuration. The 100-11-21-221 uses TO5 package. The OP913WSL uses TO-5 variant with 2 leads and lens top metal can. Physical package differences require verification of mechanical compatibility with existing PCB layouts and socket configurations.

Q: What is the inventory status of these parts?

A: SD3421-002 (obsolete) has 1170 pieces in stock. 100-11-21-221 (active) has 1190 pieces in stock. OP913WSL (active) has 798 pieces in stock. Active product status for the substitute parts supports long-term supply chain availability.