KA79M08RTF Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The KA79M08RTF is a linear voltage regulator IC manufactured by onsemi, designed to provide a fixed negative 8V output at 500mA. This device is classified as a negative fixed output regulator within the Power Management (PMIC) category and is packaged in a TO-252-3 DPAK configuration suitable for surface mount applications.

The KA79M08RTF is currently listed with Obsolete product status. Due to this obsolescence, identifying equivalent and substitute parts from active product lines is essential for design continuity, procurement reliability, and long-term system support.

Substiute Parts

KA79M08RTF

onsemiIn Stock: 789KA79M08RTF Datasheet

Current PartRFQ

MC79M08BDTRKG

onsemiIn Stock: 4408MC79M08BDTRKG Datasheet

SimilarRFQ

MC79M08CDTRKG

onsemiIn Stock: 16361MC79M08CDTRKG Datasheet

SimilarRFQ

UA79M08CKVURG3

Texas InstrumentsIn Stock: 2746UA79M08CKVURG3 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the KA79M08RTF are identified based on strict electrical and mechanical parameter matching within the negative fixed output regulator category. The following criteria determine substitution eligibility:

Critical Matching Parameters:

• Output Configuration: Negative
• Output Type: Fixed
• Voltage - Output (Min/Fixed): -8V
• Current - Output: 500mA
• Package / Case: TO-252-3, DPAK (2 Leads + Tab), SC-63
• Mounting Type: Surface Mount

Allowable Variations:

• Voltage - Input (Max): Substitute parts may have equal or lower maximum input voltage ratings (onsemi substitutes: -35V; Texas Instruments substitute: -25V)
• Operating Temperature Range: Substitute parts may have equal or extended temperature ranges
• Product Status: Active status substitutes are preferred over obsolete parts
• Packaging Format: Tape & Reel (TR), Cut Tape (CT), or Bulk formats are acceptable variations of the same component

Three substitute parts meet these criteria: MC79M08BDTRKG and MC79M08CDTRKG from onsemi, and UA79M08CKVURG3 from Texas Instruments.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: MC79M08CDTRKG

The MC79M08CDTRKG is the preferred substitute for the obsolete KA79M08RTF. Both devices share identical electrical specifications for output voltage (-8V), output current (500mA), maximum input voltage (-35V), and operating temperature range (0°C ~ 125°C). The MC79M08CDTRKG maintains Active product status with ROHS3 compliance, ensuring long-term availability and regulatory alignment. The Cut Tape (CT) & Digi-Reel® packaging format provides flexibility for both automated and manual assembly processes.

Secondary Recommendation: MC79M08BDTRKG

The MC79M08BDTRKG is an alternative onsemi substitute with identical electrical performance to the primary recommendation. This part offers an extended operating temperature range (-40°C ~ 125°C) compared to the original KA79M08RTF, providing additional thermal margin for demanding applications. Tape & Reel (TR) packaging is optimized for high-volume automated assembly. ROHS3 compliance is confirmed.

Alternative Recommendation: UA79M08CKVURG3

The UA79M08CKVURG3 from Texas Instruments is a cross-manufacturer substitute meeting all critical electrical parameters. This device provides identical output voltage (-8V) and current (500mA) specifications. The maximum input voltage rating is -25V, which is lower than the original -35V specification but remains suitable for applications with input voltage constraints within this range. The UA79M08CKVURG3 includes comprehensive protection features including Over Current, Over Temperature, and Short Circuit protection. Active product status ensures ongoing availability.

Frequently Asked Questions (FAQ)

Q: Can MC79M08BDTRKG and MC79M08CDTRKG be used interchangeably with KA79M08RTF?

A: Yes. Both onsemi substitutes are electrically and mechanically compatible with the KA79M08RTF. The primary difference is packaging format: MC79M08BDTRKG uses Tape & Reel (TR) format, while MC79M08CDTRKG uses Cut Tape (CT) & Digi-Reel® format. Selection depends on assembly process requirements and inventory management preferences.

Q: What is the key difference between the onsemi substitutes and the Texas Instruments UA79M08CKVURG3?

A: The primary difference is the maximum input voltage rating. The onsemi substitutes (MC79M08BDTRKG and MC79M08CDTRKG) support -35V maximum input, while the Texas Instruments UA79M08CKVURG3 supports -25V maximum input. For applications requiring input voltages between -25V and -35V, the onsemi substitutes are required. For applications with input voltages not exceeding -25V, the Texas Instruments part is suitable.

Q: Are there any compliance or certification differences between these substitutes?

A: The onsemi substitutes (MC79M08BDTRKG and MC79M08CDTRKG) are confirmed ROHS3 compliant. All parts listed carry REACH Unaffected status. Moisture Sensitivity Level (MSL) is rated as 1 (Unlimited) for onsemi parts, indicating no moisture sensitivity constraints during storage or handling.

Q: Does the extended temperature range of MC79M08BDTRKG (-40°C ~ 125°C) affect circuit performance compared to the original KA79M08RTF (0°C ~ 125°C)?

A: The extended temperature range of MC79M08BDTRKG does not affect performance within the original operating range (0°C ~ 125°C). The extended lower temperature capability (-40°C) provides additional operational margin for applications exposed to cold environments but is not required for designs originally specified for 0°C ~ 125°C operation.

Q: Can these substitutes be used in existing PCB layouts designed for KA79M08RTF?

A: Yes. All substitute parts use the identical TO-252-3 DPAK (2 Leads + Tab) package configuration, ensuring direct pin-compatible replacement without PCB layout modifications. Surface mount assembly processes remain unchanged.

Q: What is the difference between Tape & Reel (TR) and Cut Tape (CT) packaging?

A: Tape & Reel (TR) packaging is optimized for automated pick-and-place assembly equipment, providing continuous component feed from reel format. Cut Tape (CT) & Digi-Reel® packaging offers flexibility for both automated and manual assembly, with components supplied in tape segments. Selection depends on production volume and assembly equipment capabilities.