SLD24-18-B Equivalent & Substitute Parts

Part Overview

The SLD24-18-B is a 24V Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for through-hole applications in the P600 axial package. This component provides transient voltage protection with a 38.9V maximum clamping voltage and 131.1A peak pulse current capability. The part is classified as obsolete, making equivalent substitutes necessary for ongoing design support and procurement.

Substiute Parts

SLD24-18-B

Littelfuse Inc.In Stock: 1096SLD24-18-B Datasheet

Current PartRFQ

5KP24CA-B

LittelfuseIn Stock: 11795KP24CA-B Datasheet

DirectRFQ

SLD24-018

Littelfuse Inc.In Stock: 6079SLD24-018 Datasheet

DirectRFQ

SA24CA

Fairchild SemiconductorIn Stock: 4653SA24CA Datasheet

MFR RecommendedRFQ

15KP24CA-TP

Micro Commercial CoIn Stock: 116015KP24CA-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SLD24-18-B is determined by electrical parameter equivalence and mechanical compatibility. The critical parameters for substitution are:

• Voltage - Reverse Standoff: 24V
• Voltage - Clamping (Max) @ Ipp: 38.9V or within acceptable tolerance
• Current - Peak Pulse (10/1000µs): 131.1A or higher
• Power - Peak Pulse: 5000W or higher
• Operating Temperature Range: -55°C ~ 175°C
• Package / Case: P600 axial or compatible through-hole package
• Mounting Type: Through Hole

Substitute parts are grouped into two categories based on these criteria:

Category 1 - Direct Electrical & Mechanical Equivalents (P600 Package):

• 5KP24CA-B (Littelfuse, Active status)
• SLD24-018 (Littelfuse, Active status)

Category 2 - Electrical Equivalents with Package Variation:

• 15KP24CA-TP (Micro Commercial Co, R-6 package, higher power rating)
• SA24CA (Fairchild Semiconductor, DO-204AC package, lower current rating)

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Recommended for Direct Replacement):

5KP24CA-B and SLD24-018 are the preferred substitutes for the SLD24-18-B. Both parts are manufactured by Littelfuse, maintain active product status, and provide identical electrical specifications and P600 axial packaging. These substitutes ensure mechanical and electrical compatibility without design modification. SLD24-018 offers higher inventory availability (6000 pcs) compared to 5KP24CA-B (1162 pcs).

Secondary Substitutes (Conditional Use):

15KP24CA-TP is suitable for applications requiring higher power dissipation (15kW vs. 5kW). This part uses the R-6 axial package instead of P600, requiring PCB layout verification for mechanical fit. The clamping voltage is 40.5V, which remains within acceptable tolerance for 24V protection circuits.

SA24CA is not recommended as a direct substitute due to significantly reduced current rating (13.1A vs. 131.1A) and power capability (500W vs. 5000W). This part is suitable only for low-current transient protection applications and is obsolete.

Frequently Asked Questions (FAQ)

Q: Can 5KP24CA-B directly replace SLD24-18-B without PCB modification?

A: Yes. Both parts use the P600 axial through-hole package with identical electrical specifications (24V standoff, 38.9V clamping, 131.1A peak pulse). No design changes are required.

Q: What is the difference between SLD24-018 and 5KP24CA-B?

A: Both parts are electrically identical with matching voltage and current ratings. The primary difference is packaging format: SLD24-018 is supplied in Cut Tape (CT), while 5KP24CA-B is supplied in Bulk. SLD24-018 has higher inventory availability.

Q: Can 15KP24CA-TP be used in place of SLD24-18-B?

A: Electrically, yes, with the following considerations: 15KP24CA-TP uses the R-6 package instead of P600, requiring PCB footprint verification. The clamping voltage is 40.5V versus 38.9V. The higher power rating (15kW) provides additional margin for transient events.

Q: Why is SA24CA not recommended as a substitute?

A: SA24CA has a peak pulse current of only 13.1A and power rating of 500W, compared to the SLD24-18-B specifications of 131.1A and 5000W. This part is suitable only for low-current applications and does not meet the electrical requirements of the original design.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts maintain ROHS3 compliance, matching the environmental standards of the SLD24-18-B.

Q: What is the operating temperature range for substitute parts?

A: All substitute parts operate across the same temperature range as the SLD24-18-B: -55°C to 175°C (junction temperature).