MC7812ACT Linear Voltage Regulator - Equivalent & Substitute Parts

Part Overview

The MC7812ACT is a linear voltage regulator IC manufactured by onsemi, designed to provide a fixed positive 12V output at 1A current capacity in a TO-220-3 package. This device is classified as obsolete, which necessitates identification of equivalent and substitute components for new designs or production continuity. The MC7812ACT features integrated over-temperature and short-circuit protection, making it suitable for general-purpose power management applications requiring fixed 12V regulation.

Key Parameters

Parameter	Value
Output Voltage (Fixed)	12V
Output Current	1A
Input Voltage (Max)	35V
Voltage Dropout (Max)	2V @ 1A (Typ)
Quiescent Current	6 mA
PSRR	60dB (1kHz)
Protection Features	Over Temperature, Short Circuit
Operating Temperature	0°C ~ 125°C
Package / Case	TO-220-3
Mounting Type	Through Hole
RoHS Status	RoHS non-compliant

Substitute Part Grouping Explanation

Substitution of the MC7812ACT is determined by the following critical parameters:

Output Voltage: Must be fixed at 12V
Output Configuration: Must be positive
Package / Case: Must be TO-220-3 for mechanical and thermal compatibility
Mounting Type: Must be through-hole
Output Current: Minimum 1A (equal or greater capacity acceptable)
Input Voltage Range: Must support up to 35V maximum input
Protection Features: Must include over-temperature and short-circuit protection
Operating Temperature Range: Must cover 0°C to 125°C minimum

Substitute parts are grouped into two categories:

Direct Manufacturer Substitutes: Parts from the same manufacturer (onsemi) with identical electrical specifications and packaging, differing only in product status or packaging format.

Cross-Manufacturer Equivalents: Parts from alternative manufacturers (Texas Instruments, STMicroelectronics, Diodes Incorporated, UMW) that meet or exceed the electrical and mechanical requirements of the MC7812ACT.

Parameter Comparison

Part Number	Manufacturer	Output Current	Input Voltage (Max)	Quiescent Current	PSRR	Operating Temp	Product Status	RoHS Status
MC7812ACT	onsemi	1A	35V	6 mA	60dB (1kHz)	0°C ~ 125°C	Obsolete	Non-compliant
MC7812ACTG	onsemi	1A	35V	6 mA	60dB (1kHz)	0°C ~ 125°C	Active	ROHS3 Compliant
MC7812CTG	onsemi	1A	35V	6.5 mA	60dB (1kHz)	0°C ~ 125°C	Active	ROHS3 Compliant
UA7812CKCS	Texas Instruments	1.5A	30V	-	78dB (120Hz)	0°C ~ 125°C	Last Time Buy	ROHS3 Compliant
AS7812AT-E1	Diodes Incorporated	1A	32V	6 mA	60dB (120Hz)	-40°C ~ 125°C	Active	ROHS3 Compliant
L7812ABV	STMicroelectronics	1.5A	35V	6 mA	60dB (120Hz)	-40°C ~ 125°C	Active	ROHS3 Compliant
L7812ACV	STMicroelectronics	1.5A	35V	6 mA	60dB (120Hz)	0°C ~ 125°C	Active	ROHS3 Compliant
L7812CV	UMW	1.2A	35V	6 mA	-	-40°C ~ 105°C	Active	ROHS3 Compliant
L78M12CV	STMicroelectronics	500mA	35V	6 mA	55dB (120Hz)	0°C ~ 125°C	Active	ROHS3 Compliant
L78S12CV	STMicroelectronics	2A	35V	8 mA	47dB (120Hz)	0°C ~ 150°C	Obsolete	ROHS3 Compliant
LM340T-12/NOPB	Texas Instruments	1.5A	35V	8 mA	80dB (120Hz)	0°C ~ 125°C	Active	ROHS3 Compliant

Engineering Selection Recommendations

Primary Recommendation: MC7812ACTG (onsemi)

The MC7812ACTG is the direct successor to the MC7812ACT, offering identical electrical specifications and mechanical compatibility. This part is currently in active production status with ROHS3 compliance, making it the optimal choice for design continuity and supply chain stability. The only differences are packaging format (tube vs. bulk) and regulatory compliance status.

Secondary Recommendation: MC7812CTG (onsemi)

The MC7812CTG provides an alternative from the same manufacturer with marginally higher quiescent current (6.5 mA vs. 6 mA). This part maintains full electrical compatibility and is actively produced with ROHS3 compliance.

Cross-Manufacturer Alternatives:

LM340T-12/NOPB (Texas Instruments): Offers 1.5A output capacity with superior PSRR (80dB vs. 60dB) and is actively produced. Suitable for applications requiring enhanced noise rejection.
L7812ABV or L7812ACV (STMicroelectronics): Both provide 1.5A output capacity with extended temperature range (-40°C to 125°C). L7812ABV supports full 35V input; L7812ACV maintains 0°C to 125°C operating range. Both are actively produced with ROHS3 compliance.
AS7812AT-E1 (Diodes Incorporated): Matches the 1A output specification with extended operating temperature range (-40°C to 125°C). Actively produced with ROHS3 compliance.

Not Recommended:

L78M12CV: Output current limited to 500mA, insufficient for 1A requirement.
L78S12CV: Obsolete status despite higher current rating.
UA7812CKCS: Last Time Buy status indicates discontinued production.

Frequently Asked Questions (FAQ)

Q: Can I use a substitute part with higher output current than the MC7812ACT?

A: Yes. A substitute with equal or greater output current capacity is electrically compatible. Parts rated for 1.5A or 2A output will function correctly in applications designed for 1A, provided all other parameters remain within specification.

Q: What is the significance of the TO-220-3 package requirement?

A: The TO-220-3 package defines the physical form factor and thermal characteristics. All listed substitutes use this identical package, ensuring direct mechanical compatibility with existing PCB layouts and heat sink mounting arrangements without modification.

Q: Are there differences between onsemi's MC7812ACTG and MC7812CTG?

A: Both parts are electrically equivalent with negligible differences. The MC7812CTG has slightly higher quiescent current (6.5 mA vs. 6 mA). For most applications, this 0.5 mA difference is insignificant. MC7812ACTG is the direct replacement.

Q: Why do some substitutes have different input voltage maximums?

A: Input voltage ratings vary by manufacturer design. The MC7812ACT specifies 35V maximum; some alternatives specify 30V or 32V. Verify your circuit's maximum input voltage does not exceed the substitute part's rating. Parts rated for 35V are preferred for maximum design margin.

Q: What does ROHS3 compliance mean for my application?

A: ROHS3 compliance indicates the part meets Restriction of Hazardous Substances regulations, restricting lead and other hazardous materials. The original MC7812ACT is non-compliant. If your application or market requires ROHS compliance, select only ROHS3-compliant substitutes.

Q: Can I use L78M12CV as a substitute?

A: No. The L78M12CV is rated for only 500mA output current, which is insufficient for the 1A requirement of the MC7812ACT. This part is not a valid substitute.

Q: How do I verify thermal compatibility with a substitute part?

A: All listed substitutes use the TO-220-3 package with identical thermal characteristics. Verify the substitute's maximum junction temperature and thermal resistance specifications match or exceed your thermal design requirements. Consult the substitute manufacturer's datasheet for detailed thermal parameters.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message