20KPA68-B Equivalent & Substitute Parts

Part Overview

The 20KPA68-B is a Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection applications. This unidirectional Zener diode features a 68V reverse standoff voltage and 115.5V maximum clamping voltage with 183.6A peak pulse current capability. The part is classified as obsolete, necessitating identification of active equivalent alternatives that maintain functional compatibility for new designs and ongoing production requirements.

Substiute Parts

20KPA68-B

Littelfuse Inc.In Stock: 103220KPA68-B Datasheet

Current PartRFQ

20KPA68A

MDE Semiconductor IncIn Stock: 218020KPA68A Datasheet

DirectRFQ

20KPA68A-B

Littelfuse Inc.In Stock: 85020KPA68A-B Datasheet

DirectRFQ

BZW50-68

STMicroelectronicsIn Stock: 2227BZW50-68 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 20KPA68-B is determined by the following critical parameters:

• Voltage - Reverse Standoff: Must be 68V (±tolerance as specified by manufacturer)
• Mounting Type: Must be Through Hole to maintain PCB compatibility
• Package / Case: Must be P600 Axial or equivalent form factor
• Current - Peak Pulse (10/1000µs): Must support minimum 183.6A
• Power - Peak Pulse: Must support minimum 20000W (20kW)
• Operating Temperature Range: Must encompass -55°C ~ 175°C (TJ)
• Type: Zener diode, unidirectional configuration

Substitute parts are grouped into two categories based on these parameters: direct functional equivalents from alternative manufacturers and manufacturer-recommended alternatives with comparable electrical performance.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Direct Equivalents):

The 20KPA68A-B (Littelfuse Inc.) and 20KPA68A (MDE Semiconductor Inc) are the preferred substitutes for the obsolete 20KPA68-B. Both parts maintain identical reverse standoff voltage (68V), peak pulse current (183.6A), and power dissipation (20kW) specifications. The 20KPA68A-B remains in active production status from the original manufacturer, ensuring long-term availability and supply chain continuity. Both alternatives are ROHS3 compliant and support the full operating temperature range of -55°C to 175°C (TJ).

The 20KPA68A-B exhibits a slightly lower clamping voltage (110V vs. 115.5V), which represents a marginal improvement in voltage regulation performance. The 20KPA68A from MDE Semiconductor Inc provides an alternative source with identical electrical specifications and active product status.

Secondary Substitute (Manufacturer-Recommended):

The BZW50-68 from STMicroelectronics is designated as a manufacturer-recommended alternative. This part maintains the 68V reverse standoff voltage and through-hole axial mounting configuration. However, the BZW50-68 exhibits significant differences in peak pulse current (382A vs. 183.6A) and power dissipation (5kW vs. 20kW), indicating different application suitability. The R-6 package differs from the P600 package, requiring PCB layout verification. This substitute is suitable only for applications where the reduced power handling and different package form factor are acceptable.

Frequently Asked Questions (FAQ)

Q: Can the 20KPA68A-B directly replace the 20KPA68-B without PCB modifications?

A: Yes. The 20KPA68A-B maintains identical package specifications (P600, Axial), mounting type (Through Hole), and electrical performance parameters (68V standoff, 183.6A peak pulse, 20kW power). No PCB layout changes are required.

Q: What is the primary reason for substituting the 20KPA68-B?

A: The 20KPA68-B is classified as obsolete. The 20KPA68A-B and 20KPA68A are active products that provide equivalent functionality with assured long-term availability.

Q: Are there compliance differences between the main part and substitutes?

A: All substitute parts maintain ROHS3 compliance equivalent to the main part. The 20KPA68A-B and 20KPA68A provide REACH Unaffected status, offering additional regulatory assurance.

Q: Why is the BZW50-68 listed as a substitute if it has different electrical specifications?

A: The BZW50-68 is designated as a manufacturer-recommended alternative based on the same 68V reverse standoff voltage classification. However, the significantly different peak pulse current (382A vs. 183.6A) and power dissipation (5kW vs. 20kW) restrict its use to applications with lower transient energy requirements. Package differences (R-6 vs. P600) require design verification.

Q: What parameters must remain constant for a valid substitution?

A: The critical parameters for substitution are: Voltage - Reverse Standoff (68V), Mounting Type (Through Hole), and Package / Case compatibility. Peak pulse current and power dissipation must meet or exceed the original specification (183.6A, 20kW respectively).

Q: Is operating temperature range a factor in substitution selection?

A: Yes. The 20KPA68A-B and 20KPA68A both support the full operating temperature range of -55°C to 175°C (TJ), matching the original part. The BZW50-68 does not specify an operating temperature range, requiring application-specific verification.