Description

Marked "MC78M12ABT" on the package, 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 a high accuracy tolerance ($\pm 2\%$) and deliver up to $500\text{ mA}$ of continuous output current when paired with adequate heat sinking.

The MC78M12 incorporates built-in thermal overload protection, internal short-circuit current limiting, and output transistor safe-area compensation, making it robust against electrical faults and load fluctuations.

Key Specifications

• Type: Positive Fixed Linear Voltage Regulator

• Manufacturer: ON Semiconductor (onsemi)

• Package Marking: MC78M12ABT

• Package: TO-220 (3-pin through-hole)

• 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

• 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 systems

• Power distribution networks and industrial control boards

• Post-regulator for switching power supplies to reduce voltage ripple

• Power supply modules for sensors, microcontrollers, and operational amplifiers

Package Includes

• 1 x ON Semiconductor MC78M12ABT 12V 500mA Voltage Regulator (TO-220)