The MC79L18ACPX is a three-terminal negative voltage regulator manufactured by ON Semiconductor (formerly Fairchild). This regulator provides a fixed output voltage of -18V with a low dropout voltage. It is widely used in electronic circuits to provide a stable negative power supply for various components and systems, particularly in applications requiring a reliable negative voltage source. The 'L' in the part number denotes a low current version.

Applications

• Linear Power Supplies: Provides a regulated -18V output for various circuits.
• Instrumentation: Powering operational amplifiers and other analog circuits requiring a negative supply.
• Voltage Regulators: General-purpose voltage regulation in electronic devices.
• Battery-Powered Devices: Providing a stable negative supply in portable applications.
• Audio Amplifiers: Biasing and powering audio circuits.

Features

• Fixed Output Voltage: Provides a stable -18V output.
• Low Dropout Voltage: Operates with a small difference between input and output voltage.
• Internal Short Circuit Current Limiting: Protects the regulator from damage due to short circuits.
• Thermal Overload Protection: Shuts down the regulator to prevent overheating.
• Output Transistor Safe-Area Compensation: Enhances reliability under varying load conditions.

Benefits

• Simple to Use: Requires minimal external components.
• Reliable: Provides stable and reliable voltage regulation.
• Protected: Incorporates short circuit and thermal overload protection.
• Cost-Effective: A low-cost solution for negative voltage regulation.

Additional Details

The MC79L18ACPX is available in a TO-92 package. It typically has an input voltage range of -20.5V to -35V. The output current is typically 100mA. This is a three-terminal regulator, with pins for input, output, and ground. It requires minimal external components, which simplifies circuit implementation. The built-in protection features ensure reliable operation and prevent damage to the regulator and connected components. It is frequently used to provide a stable negative supply for operational amplifiers, data converters, and other analog circuitry that require a negative supply. The regulator provides excellent line and load regulation, ensuring a stable output voltage under varying input voltage and load conditions. The low dropout voltage feature allows it to operate efficiently even when the input voltage is only slightly higher than the output voltage. The internal short circuit current limiting protects the regulator from damage in case of a short circuit on the output. The thermal overload protection shuts down the regulator when it gets too hot, preventing damage due to overheating. The output transistor safe-area compensation helps maintain stable operation under varying load conditions and temperature.