KA33VTA Zener Diode Equivalent & Substitute Parts

Part Overview

The KA33VTA is a 33 V, 200 mW Zener diode manufactured by onsemi in a TO-92-2 through-hole package. This component is classified as obsolete, necessitating identification of active equivalent parts for new designs and ongoing production requirements. The KA33VTA serves as a voltage regulation and protection element in electronic circuits requiring 33 V reference or clamping functionality.

Due to its obsolete status, sourcing new units from the original manufacturer is no longer available through standard distribution channels. Equivalent substitute parts with matching or superior electrical characteristics and compatible through-hole mounting are required to maintain design continuity and ensure circuit performance.

Substiute Parts

KA33VTA

onsemiIn Stock: 4251KA33VTA Datasheet

Current PartRFQ

2EZ33D5-TP

Micro Commercial CoIn Stock: 58092EZ33D5-TP Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the KA33VTA is determined by the following critical electrical and mechanical parameters:

Electrical Matching Criteria:

• Zener voltage nominal value of 33 V
• Through-hole mounting configuration
• Voltage tolerance within acceptable circuit design margins
• Maximum impedance specification compatibility
• Operating temperature range sufficient for application requirements

Mechanical Compatibility:

• Through-hole package format (axial or radial lead configuration)
• Physical dimensions permitting board layout accommodation

The substitute part 2EZ33D5-TP meets the primary electrical requirements of 33 V nominal Zener voltage and through-hole mounting. While this part exhibits higher power dissipation capability (2 W versus 200 mW) and improved tolerance (±5% versus ±6%), it remains functionally equivalent for circuits designed around the KA33VTA specification. The expanded operating temperature range (-55°C to 150°C) and active product status provide additional advantages for new designs.

Parameter Comparison

Engineering Selection Recommendations

For Direct Substitution:

The 2EZ33D5-TP is suitable as a direct functional replacement for the KA33VTA in applications where the 33 V Zener voltage specification is the primary design requirement. Both components maintain REACH compliance and unlimited moisture sensitivity classification, ensuring regulatory and environmental compatibility.

Product Status Consideration:

The KA33VTA's obsolete classification makes the 2EZ33D5-TP the preferred selection for new production and design implementations. The substitute part carries active product status, ensuring long-term availability and supply chain stability.

Electrical Performance:

The 2EZ33D5-TP provides superior electrical characteristics relative to the KA33VTA: improved tolerance (±5% versus ±6%), lower maximum impedance (23 Ohms versus 25 Ohms), and significantly higher power dissipation capability (2 W versus 200 mW). These enhancements do not introduce incompatibility; rather, they provide design margin and thermal performance advantages.

Package Transition:

The transition from TO-92-2 (radial lead) to DO-41 (axial lead) packaging requires board layout modification. Both packages utilize through-hole mounting technology and are mechanically compatible with standard PCB hole spacing. Design verification of lead routing and component placement is necessary prior to production implementation.

Frequently Asked Questions (FAQ)

Q: Can the 2EZ33D5-TP directly replace the KA33VTA without circuit modification?

A: The 2EZ33D5-TP is electrically compatible with the KA33VTA for circuits designed around the 33 V Zener voltage specification. The substitute part's superior electrical characteristics (lower tolerance, lower impedance, higher power rating) do not introduce functional incompatibility. Physical board layout modification is required due to package format differences (DO-41 axial versus TO-92-2 radial).

Q: What is the significance of the power rating difference between these parts?

A: The KA33VTA is rated for 200 mW maximum power dissipation, while the 2EZ33D5-TP is rated for 2 W. In applications where the KA33VTA operates near its thermal limits, the 2EZ33D5-TP provides improved thermal margin and reduced junction temperature. For circuits designed within the 200 mW specification, both parts operate identically.

Q: Are there compliance or regulatory differences between these parts?

A: Both the KA33VTA and 2EZ33D5-TP maintain identical REACH compliance status (REACH Unaffected) and moisture sensitivity classification (MSL 1 - Unlimited). No regulatory or environmental compliance barriers exist for substitution.

Q: How do the tolerance specifications affect circuit design?

A: The KA33VTA specifies ±6% tolerance, while the 2EZ33D5-TP specifies ±5% tolerance. The 2EZ33D5-TP provides tighter voltage regulation with reduced variation across the production population. For circuits with strict voltage reference requirements, the improved tolerance of the substitute part enhances performance.

Q: What is the impact of the operating temperature range difference?

A: The KA33VTA operates from -20°C to 75°C, while the 2EZ33D5-TP operates from -55°C to 150°C. For applications within the KA33VTA's temperature range, both parts perform identically. The 2EZ33D5-TP is suitable for extended temperature applications beyond the original part's specification.

Q: Does the impedance difference affect circuit performance?

A: The KA33VTA specifies maximum impedance of 25 Ohms; the 2EZ33D5-TP specifies 23 Ohms. This minor difference (2 Ohms) is negligible in most circuit applications. The lower impedance of the substitute part provides marginally improved voltage regulation stability.

Q: What packaging considerations apply to this substitution?

A: The KA33VTA uses TO-92-2 (radial lead) packaging; the 2EZ33D5-TP uses DO-41 (axial lead) packaging. Both are through-hole components with compatible PCB mounting technology. Physical component placement and lead routing require board layout adjustment. Lead spacing and hole diameter compatibility must be verified for your specific PCB design.