KA78L05AAZBU Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The KA78L05AAZBU is a linear voltage regulator IC manufactured by onsemi, designed to provide a fixed positive 5V output at 100mA. This device features integrated over-temperature and short-circuit protection, operating across an input voltage range of up to 30V with a quiescent current of 5.5mA. The part is currently classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

KA78L05AAZBU

onsemiIn Stock: 1139KA78L05AAZBU Datasheet

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MC78L05ABPG

onsemiIn Stock: 2217MC78L05ABPG Datasheet

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MC78L05ACPG

onsemiIn Stock: 9952MC78L05ACPG Datasheet

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NCV78L05ABPG

onsemiIn Stock: 764NCV78L05ABPG Datasheet

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L78L05ABZ

STMicroelectronicsIn Stock: 55124L78L05ABZ Datasheet

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L78L05ACZ

STMicroelectronicsIn Stock: 297948L78L05ACZ Datasheet

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L78L05CZ

STMicroelectronicsIn Stock: 3452L78L05CZ Datasheet

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LM78L05ACZ/LFT4

National SemiconductorIn Stock: 2737LM78L05ACZ/LFT4 Datasheet

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LM78L05ACZ/NOPB

Texas InstrumentsIn Stock: 5547LM78L05ACZ/NOPB Datasheet

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UA78L05ACLP

Texas InstrumentsIn Stock: 2258UA78L05ACLP Datasheet

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UA78L05ACLPE3

Texas InstrumentsIn Stock: 4484UA78L05ACLPE3 Datasheet

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UA78L05AILP

Texas InstrumentsIn Stock: 28933UA78L05AILP Datasheet

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UA78L05AILPE3

Texas InstrumentsIn Stock: 2576UA78L05AILPE3 Datasheet

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UA78L05CLP

Texas InstrumentsIn Stock: 1425UA78L05CLP Datasheet

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UA78L05CLPE3

Texas InstrumentsIn Stock: 7370UA78L05CLPE3 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the KA78L05AAZBU is determined by the following critical parameters:

• Fixed output voltage of 5V
• Output current capability of 100mA
• Maximum input voltage of 30V or greater
• Through-hole TO-92-3 package compatibility
• Positive output configuration with fixed regulation
• Protection against over-temperature and short-circuit conditions

Substitute parts must maintain electrical equivalence across these parameters. Parts with identical or superior specifications in input voltage rating, quiescent current performance, and protection features are considered direct substitutes. Package compatibility is mandatory for board-level integration without redesign.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Active Status, Matched Temperature Range)

L78L05ACZ (STMicroelectronics) and MC78L05ACPG (onsemi) are direct substitutes for applications requiring 0°C to 125°C operation. Both maintain identical output specifications, package compatibility, and RoHS3 compliance. L78L05ACZ offers superior inventory availability (297,853 units) and matching quiescent current (5.5mA).

Extended Temperature Range Alternatives

MC78L05ABPG (onsemi) and L78L05ABZ (STMicroelectronics) extend operating range to -40°C to 125°C, suitable for industrial and automotive environments. NCV78L05ABPG provides automotive-grade qualification (AEC-Q100) with identical electrical specifications.

Enhanced Performance Options

LM78L05ACZ/LFT4 (National Semiconductor) and LM78L05ACZ/NOPB (Texas Instruments) offer superior PSRR (62dB vs. 80dB of original), lower quiescent current (3mA), and higher input voltage rating (35V). These are suitable for noise-sensitive applications.

Not Recommended for New Designs

L78L05CZ (STMicroelectronics) carries "Not For New Designs" status. UA78L05ACLP and UA78L05ACLPE3 (Texas Instruments) are in "Last Time Buy" status with reduced maximum input voltage (20V), limiting their application scope.

Frequently Asked Questions (FAQ)

Q: Can I use MC78L05ACPG as a direct replacement for KA78L05AAZBU?

A: Yes. MC78L05ACPG maintains identical output voltage (5V), output current (100mA), input voltage rating (30V), and TO-92-3 package. Both feature over-temperature and short-circuit protection. The operating temperature range matches (0°C to 125°C). This is a direct electrical and mechanical substitute.

Q: What is the difference between MC78L05ABPG and MC78L05ACPG?

A: Both are onsemi products with identical electrical specifications. The primary difference is operating temperature range: MC78L05ABPG operates from -40°C to 125°C, while MC78L05ACPG operates from 0°C to 125°C. Select MC78L05ABPG for extended low-temperature applications.

Q: Why do LM78L05ACZ variants show different quiescent current (3mA vs. 5.5mA)?

A: LM78L05ACZ variants from National Semiconductor and Texas Instruments feature improved internal design with lower quiescent current. This reduces power dissipation in standby conditions while maintaining all other electrical parameters. This is a performance advantage with no compatibility impact.

Q: Is NCV78L05ABPG suitable for automotive applications?

A: Yes. NCV78L05ABPG carries AEC-Q100 automotive qualification and maintains all electrical specifications of the original part. It is specifically qualified for automotive-grade reliability requirements.

Q: Can I use UA78L05ACLP if my input voltage exceeds 20V?

A: No. UA78L05ACLP has a maximum input voltage rating of 20V, compared to 30V for the original KA78L05AAZBU. Using this part with input voltages above 20V exceeds device ratings and may cause failure. Select alternatives with 30V or higher input ratings.

Q: Are all substitute parts RoHS3 compliant?

A: Most active substitutes are RoHS3 compliant. L78L05CZ is RoHS3 compliant but carries "Not For New Designs" status. UA78L05ACLP and UA78L05ACLPE3 are RoHS3 compliant but in "Last Time Buy" status. Verify compliance status for your specific application requirements.

Q: What is the package compatibility requirement?

A: All listed substitutes use TO-92-3 (TO-226-3) through-hole packaging, ensuring direct board-level compatibility without PCB redesign. Pin configuration and lead spacing are identical across all listed parts.