onsemi MC78M05CDTRK 5V Positive Voltage Regulator: Datasheet, Pinout, and Application Circuits

The onsemi MC78M05CDTRK is a classic, fixed-output, linear voltage regulator belonging to the ubiquitous 78xx family. It is engineered to deliver a stable +5V DC output voltage at currents up to 500mA, making it a fundamental component in a vast array of electronic devices. Housed in a space-saving DPAK surface-mount package, it is ideal for modern PCB designs where board real estate is at a premium. This component is renowned for its simplicity, reliability, and cost-effectiveness, providing essential power regulation for microcontrollers, logic circuits, sensors, and other low-power ICs.

Datasheet Overview and Key Specifications

A thorough review of the MC78M05CDTRK datasheet is crucial for successful implementation. Key specifications that define its operational limits and performance include:

Output Voltage: +5V ±4% (approx. 4.8V to 5.2V).

Output Current: Maximum 500mA.

Input Voltage Range: 7V to 35V. A minimum input-to-output differential voltage (dropout voltage) of 2V is typically required for proper regulation. Therefore, the input must be maintained above 7V to ensure a stable 5V output.

Line Regulation: 6 mV (Typ.) – Measures the output voltage change for a specific input voltage change.

Load Regulation: 12 mV (Typ.) – Measures the output voltage change for a specific load current change.

Thermal Protection: The IC includes internal thermal shutdown circuitry that disables the device if the junction temperature exceeds safe limits, protecting it from damage due to overheating.

Short Circuit Protection: The output current is internally limited, safeguarding the regulator in case of a short circuit on the output.

Operating Junction Temperature: -40°C to +125°C.

Pinout Configuration

The MC78M05CDTRK comes in a DPAK (TO-252) package with three pins:

1. Input (IN): This pin receives the unregulated DC input voltage, which must be higher than the required output voltage.

2. Ground (GND): The common ground reference for both the input and output circuits.

3. Output (OUT): This pin provides the regulated +5V output.

Standard Application Circuits

The basic application circuit for the MC78M05CDTRK is remarkably straightforward, requiring only two external capacitors for stability.

1. Basic Regulation Circuit:

The most common application involves placing a 0.33μF ceramic capacitor at the input pin (IN) and a 0.1μF ceramic capacitor at the output pin (OUT). The input capacitor helps suppress high-frequency noise and can handle transient spikes, while the output capacitor improves the regulator's transient response and stability.

2. Enhanced Stability Circuit:

For scenarios with a variable load or a input source that is located far from the regulator, adding a larger electrolytic or tantalum capacitor (e.g., 10μF to 100μF) at both the input and output is highly recommended. This provides better bulk filtering and ensures stability under a wider range of conditions.

ICGOODFIND Summary

The onsemi MC78M05CDTRK stands as a quintessential solution for medium-current 5V power regulation. Its greatest strengths lie in its exceptional simplicity, robust built-in protections (thermal and short-circuit), and high reliability. While less efficient than switching regulators, its minimal external component count and noise-free output make it the perfect choice for powering digital logic, various ICs, and sensors in applications ranging from consumer electronics to industrial control systems where a stable, clean voltage rail is paramount.

Keywords:

Voltage Regulator

5V Output

Linear Regulator

500mA

DPAK Package