KA78M05RTM Equivalent & Substitute Parts

Part Overview

The KA78M05RTM is a linear voltage regulator IC from onsemi, designed to provide a fixed positive 5V output at 500mA in a DPAK surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The device features integrated over-temperature and short-circuit protection, suitable for power management applications requiring stable 5V regulation from input sources up to 35V.

Key Parameters

Parameter	Value
Manufacturer	onsemi
Output Voltage (Fixed)	5V
Output Current	500mA
Input Voltage (Max)	35V
Voltage Dropout (Max)	2V @ 500mA (Typ)
Quiescent Current	6 mA
PSRR	80dB (120Hz)
Protection Features	Over Temperature, Short Circuit
Operating Temperature	-40°C ~ 125°C
Package / Case	TO-252-3, DPAK (2 Leads + Tab), SC-63
Mounting Type	Surface Mount
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution for the KA78M05RTM is determined by the following critical parameters:

Output Voltage: Must be fixed at 5V
Output Current Capability: Minimum 500mA required
Package Type: TO-252-3 DPAK surface mount only
Input Voltage Rating: Maximum 35V
Protection Features: Over-temperature and short-circuit protection required
Output Configuration: Positive fixed output only

Substitute parts are grouped into two categories:

Direct Equivalents (500mA Output Current): Parts with identical 500mA output current rating, maintaining the same thermal and current handling characteristics as the original KA78M05RTM.

Higher Current Alternatives (1A Output Current): Parts rated for 1A output current. These provide enhanced current capability while maintaining all other electrical parameters and package compatibility. These are suitable for applications where additional current margin is beneficial.

Parameter Comparison

Part Number	Manufacturer	Output Current	Output Voltage	Input Voltage (Max)	Operating Temp	PSRR (120Hz)	Quiescent Current	Product Status	Packaging
KA78M05RTM	onsemi	500mA	5V	35V	-40°C ~ 125°C	80dB	6 mA	Obsolete	DPAK
MC78M05CDTRKG	onsemi	500mA	5V	35V	0°C ~ 125°C	80dB	Not specified	Active	Cut Tape (CT) & Digi-Reel®
MC78M05ABDTG	onsemi	500mA	5V	35V	-40°C ~ 125°C	80dB	Not specified	Active	Tube
MC78M05ACDTRKG	onsemi	500mA	5V	35V	0°C ~ 125°C	80dB	Not specified	Active	Cut Tape (CT) & Digi-Reel®
MC78M05BDTG	onsemi	500mA	5V	35V	-40°C ~ 125°C	80dB	Not specified	Active	Tube
MC78M05CDTG	onsemi	500mA	5V	35V	0°C ~ 125°C	80dB	Not specified	Active	Tube
MC7805BDTG	onsemi	1A	5V	35V	-40°C ~ 125°C	68dB	8 mA	Active	Tube
MC7805BDTRKG	onsemi	1A	5V	35V	-40°C ~ 125°C	68dB	8 mA	Active	Cut Tape (CT) & Digi-Reel®
MC7805CDTG	onsemi	1A	5V	35V	0°C ~ 125°C	83dB	6.5 mA	Active	Tube
MC7805CDTRKG	onsemi	1A	5V	35V	0°C ~ 125°C	83dB	6.5 mA	Active	Cut Tape (CT) & Digi-Reel®
NCV7805BDTRKG	onsemi	1A	5V	35V	-40°C ~ 125°C	83dB	8 mA	Active	Cut Tape (CT) & Digi-Reel®

Engineering Selection Recommendations

For Direct Replacement (500mA Applications):

MC78M05CDTRKG, MC78M05ABDTG, MC78M05ACDTRKG, MC78M05BDTG, and MC78M05CDTG are active production alternatives to the obsolete KA78M05RTM. All maintain 500mA output current and 5V fixed output voltage in DPAK packaging. Selection between these parts depends on operating temperature requirements and packaging format:

Parts with "A" designation (MC78M05ABDTG, MC78M05ACDTRKG) support -40°C ~ 125°C operating range, matching the original part's temperature specification.
Parts with "C" designation (MC78M05CDTRKG, MC78M05CDTG) operate from 0°C ~ 125°C.
Cut Tape & Digi-Reel® packaging (CDTRKG, ACDTRKG) is suitable for automated assembly; Tube packaging (ABDTG, BDTG, CDTG) is suitable for manual or bulk handling.

For Enhanced Current Capability (1A Applications):

MC7805BDTG, MC7805BDTRKG, MC7805CDTG, MC7805CDTRKG, and NCV7805BDTRKG provide 1A output current in the same DPAK package. These are applicable when the application requires higher current margin or when upgrading from 500mA to 1A capacity:

MC7805 series (non-automotive) is suitable for industrial and commercial applications.
NCV7805BDTRKG carries AEC-Q100 automotive qualification and is suitable for automotive-grade applications.
Operating temperature ranges vary: -40°C ~ 125°C for B-grade parts; 0°C ~ 125°C for C-grade parts.

All substitute parts are RoHS3 compliant and carry identical REACH and ECCN classifications as the original part.

Frequently Asked Questions (FAQ)

Q: Can I use a 1A rated part (MC7805 series) as a direct replacement for the 500mA KA78M05RTM?

A: Yes. The 1A parts maintain identical 5V output voltage, 35V maximum input voltage, DPAK package, and protection features. The higher current rating provides additional design margin and does not create compatibility issues in 500mA applications. However, thermal dissipation characteristics may differ slightly due to different quiescent current specifications.

Q: What is the difference between Cut Tape & Digi-Reel® and Tube packaging?

A: Both packaging formats contain the same die and electrical performance. Cut Tape & Digi-Reel® packaging is optimized for automated pick-and-place assembly equipment. Tube packaging is suitable for manual assembly or bulk component handling. Package selection depends on manufacturing process requirements, not electrical performance.

Q: Why do some substitute parts have different operating temperature ranges?

A: Parts designated with "A" or "B" grades support -40°C ~ 125°C operation, matching the original KA78M05RTM specification. Parts designated with "C" grade operate from 0°C ~ 125°C. For applications requiring full -40°C ~ 125°C range, select parts with "A" or "B" designation.

Q: Is the NCV7805BDTRKG suitable for my application?

A: NCV7805BDTRKG is qualified to AEC-Q100 automotive standards and is suitable for automotive-grade applications. It provides 1A output current, 5V fixed output, and -40°C ~ 125°C operating range in DPAK packaging. Use this part only if automotive qualification is a requirement for your application.

Q: What does PSRR (Power Supply Rejection Ratio) mean for my selection?

A: PSRR measures the regulator's ability to reject noise on the input supply. Higher PSRR values indicate better noise rejection. The KA78M05RTM specifies 80dB PSRR. Most substitute parts maintain this specification or exceed it (up to 83dB for C-grade MC7805 parts). This parameter does not affect substitution compatibility.

Q: Are all substitute parts from onsemi?

A: Yes. All substitute parts listed are manufactured by onsemi, ensuring consistent quality standards and design compatibility with the original KA78M05RTM.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message