EPS28 Equivalent & Substitute Parts

Part Overview

The EPS28 is an active Transient Voltage Suppressor (TVS) diode manufactured by Microchip Technology, designed for general-purpose transient protection applications. This through-hole axial component operates across a temperature range of -65°C to 175°C and provides bidirectional suppression with a 28V reverse standoff voltage. The EPS28 is classified as a Zener-type TVS diode and is currently in active product status. Substitute parts are identified to address packaging availability, compliance requirements, or inventory considerations while maintaining functional equivalence within specified electrical parameters.

Substiute Parts

EPS28

Microchip TechnologyIn Stock: 927EPS28 Datasheet

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1.5KE33A

Good-Ark SemiconductorIn Stock: 348781.5KE33A Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the EPS28 are identified based on electrical parameter compatibility within the following criteria:

Voltage Parameters: Reverse standoff voltage, breakdown voltage, and clamping voltage must fall within acceptable tolerance ranges to ensure equivalent transient suppression performance at the protected circuit node.

Current Handling: Peak pulse current rating must be sufficient to conduct transient energy without exceeding thermal limits.

Power Dissipation: Peak pulse power rating must accommodate the energy absorption requirements of the application.

Temperature Range: Operating temperature limits must encompass the thermal environment of the target application.

Mounting and Package: Through-hole axial configuration is required for mechanical and electrical compatibility with existing PCB layouts.

Compliance Status: RoHS and REACH compliance certifications are evaluated for regulatory alignment with end-use requirements.

The 1.5KE33A qualifies as a functional substitute based on comparable voltage parameters, higher current capacity, and superior power dissipation capability, despite differences in package designation and unidirectional channel configuration.

Parameter Comparison

Engineering Selection Recommendations

Electrical Compatibility: The 1.5KE33A demonstrates electrical equivalence to the EPS28 across all critical voltage parameters. The reverse standoff voltage (28.2V) and breakdown voltage (31.4V) are within 1% of the main part specifications. The clamping voltage (45.7V) is 4.4% lower, providing superior transient suppression. Peak pulse current capacity is 71% higher (32.8A versus 19.2A), and peak pulse power is 10 times greater (1500W versus 150W), enabling operation in higher-energy transient environments.

Temperature Range: The 1.5KE33A operates across -55°C to 175°C, which covers the upper temperature limit of the EPS28 but has a 10°C higher minimum operating temperature. This difference is acceptable for applications not requiring operation below -55°C.

Compliance Status: The 1.5KE33A is ROHS3 compliant, whereas the EPS28 is RoHS non-compliant. Selection of the 1.5KE33A is required for applications subject to RoHS regulatory requirements. Both parts are REACH Unaffected.

Package Considerations: The EPS28 uses package designation A, Axial, while the 1.5KE33A uses DO-201AE, Axial. Both are through-hole axial configurations with compatible mechanical footprints for standard PCB layouts. Physical dimensions may differ slightly; verification against PCB design specifications is necessary.

Inventory and Availability: The 1.5KE33A has significantly higher inventory availability (34,829 pieces) compared to the EPS28 (854 pieces), supporting supply chain continuity.

Frequently Asked Questions (FAQ)

Q: Can the 1.5KE33A directly replace the EPS28 in existing designs?

A: The 1.5KE33A is electrically equivalent to the EPS28 across voltage parameters and is mechanically compatible as a through-hole axial component. However, the DO-201AE package may have different physical dimensions than the A, Axial package. PCB layout verification is required to confirm mechanical fit. The unidirectional channel configuration of the 1.5KE33A differs from the bidirectional configuration of the EPS28; application requirements must confirm unidirectional suppression is acceptable.

Q: What are the key voltage parameters that determine substitution compatibility?

A: Reverse standoff voltage, breakdown voltage, and clamping voltage are the primary electrical parameters. The 1.5KE33A maintains standoff and breakdown voltages within 1% of the EPS28, ensuring equivalent circuit protection thresholds. Clamping voltage is 4.4% lower, which improves transient suppression performance.

Q: Does the higher power rating of the 1.5KE33A affect circuit operation?

A: No. The 1.5KE33A's 1500W peak pulse power rating is a capability specification indicating the component can safely dissipate higher transient energy levels. In applications where the EPS28's 150W rating is sufficient, the 1.5KE33A operates within its design envelope without adverse effects. The higher rating provides design margin for future application scaling.

Q: Are there temperature range limitations when substituting the 1.5KE33A?

A: The 1.5KE33A operates from -55°C to 175°C, compared to the EPS28's -65°C to 175°C range. Applications requiring operation below -55°C must retain the EPS28. For applications within the -55°C to 175°C range, the 1.5KE33A is fully compatible.

Q: What is the significance of the RoHS compliance difference?

A: The 1.5KE33A is ROHS3 compliant, while the EPS28 is RoHS non-compliant. Applications subject to RoHS regulatory requirements (including EU and many international markets) must use the 1.5KE33A. The EPS28 is suitable only for applications with no RoHS compliance mandate.

Q: How do bidirectional and unidirectional channel configurations affect substitution?

A: The EPS28 is bidirectional (protects against transients in both polarities), while the 1.5KE33A is unidirectional (protects against transients in one polarity only). Substitution is valid only if the application circuit requires unidirectional protection or if the protected signal is inherently single-polarity. Bidirectional protection requirements necessitate retention of the EPS28 or selection of an alternative bidirectional substitute.