Description
Marked "MC78M12ABT" on the package with ON Semiconductor's logo, this is ON Semiconductor's MC78M12ABT (from the MC78M00A series), a 3-terminal positive linear voltage regulator. It is engineered to provide a fixed $12\text{ V}$ output with tight voltage tolerance ($\pm 2\%$) and deliver up to $500\text{ mA}$ of continuous output current when paired with an adequate heat sink.
The MC78M12 series incorporates internal thermal overload protection, short-circuit current limiting, and output transistor safe-area compensation, making it highly reliable and resistant to electrical overstress.
Key Specifications
-
Type: Positive Fixed Linear Voltage Regulator
-
Manufacturer: ON Semiconductor (onsemi)
-
Package Marking: MC 78M12ABT / AF01M25G
-
Package: TO-220 (3-pin through-hole with metal mounting tab)
-
Output Voltage ($V_{OUT}$): $12\text{ V}$ (Fixed, $\pm 2\%$ tolerance)
-
Input Voltage Max ($V_{IN}$): $35\text{ V}$
-
Output Current ($I_{OUT}$): $500\text{ mA}$ ($0.5\text{ A}$) max
-
Dropout Voltage ($V_{IN} - V_{OUT}$): $2.0\text{ V}$ typical at $I_{OUT} = 500\text{ mA}$
-
Ripple Rejection (PSRR): $80\text{ dB}$ at $120\text{ Hz}$
-
Quiescent Current ($I_B$): $3.2\text{ mA}$ typical
-
Operating Temperature Range: $-40^\circ\text{C}$ to $+125^\circ\text{C}$
Common Applications
-
Local on-card voltage regulation for embedded system boards
-
Power distribution and industrial control electronics
-
Post-regulator for switching power supplies to eliminate high-frequency ripple
-
Stable $12\text{ V}$ power delivery for operational amplifiers, sensors, and microcontrollers
Package Includes
-
1 x ON Semiconductor MC78M12ABT 12V 500mA Voltage Regulator (TO-220)
