MC78M12ABT 12V 500mA Voltage Regulator

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)