MC7818ACT

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Overview

The MC7818ACTG is a monolithic integrated circuit fixed positive voltage regulator from the MC7800A series by onsemi. It provides a nominal output voltage of 18 V with an output current capability exceeding 1.0 A. The device features internal thermal overload protection, short-circuit current limiting, and output transistor safe-area compensation. Electrical characteristics specify a line regulation of 3.2 mV (typical) and load regulation of 1.8 mV (typical) at 500 mA. Ripple rejection is typically 57 dB at 120 Hz. The component operates within a junction temperature range of -40°C to +125°C and is available in standard three-lead transistor packages.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Feature Summary

• Internal thermal overload protection shuts down the circuit during excessive power conditions.
• Internal short-circuit current limiting protects against output faults.
• Output transistor safe-area compensation reduces short-circuit current as voltage across the pass transistor increases.
• No external components are required for basic fixed-voltage regulation applications.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Applications

• Local on-card voltage regulation
• Positive voltage regulation in power supplies
• Pre-regulator stages for adjustable regulators

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Procurement Notes

Verify the specific ordering suffix to confirm package type and tolerance grade. The datasheet lists MC7818AC as a distinct variant with specific electrical limits. Ensure the selected part number matches the required operating temperature range and packaging style for the intended design implementation.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Selection Notes

Select this regulator for applications requiring a stable 18 V DC source with moderate current demands. Consider the dropout voltage requirements relative to the input supply ripple. Verify that the thermal management strategy accommodates the power dissipation calculated from the input-output voltage differential and load current.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Part Context

This component belongs to the MC7800 family of three-terminal positive linear voltage regulators. The 'A' designation indicates tighter electrical tolerances compared to the standard MC7800 series. These devices are widely used in general-purpose electronics where reliable, fixed-rail power distribution is necessary without complex feedback networks.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Replacement Considerations

MC7818CTG

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators FAQ

What is the typical ripple rejection for the MC7818ACTG?

The typical ripple rejection is 57 dB at a frequency of 120 Hz.

Does the MC7818ACTG require external capacitors for stability?

External capacitors are not strictly required for stability, but an input bypass capacitor is recommended if long wire lengths connect the regulator to the power supply filter.