LM78L05 Linear Voltage Regulator 5V 100mA TO-92

The LM78L05 is a three-terminal, positive linear voltage regulator that provides a stable, fixed 5V output up to 100mA. Housed in a compact TO-92 through-hole package, it’s a reliable choice for powering low-current microcontroller circuits, sensors, and electronics modules in both professional designs and hobby projects with Arduino and Raspberry Pi peripherals.

Key Features 🧰

• Fixed 5V output for stable logic-level power
• 100mA output current capability
• Integrated thermal overload protection 🛡️
• Short-circuit protection for robust operation 🛡️
• Output transistor Safe Operating Area (SOA) compensation for reliability

Technical Specifications 📐

• Output Voltage: 5V (fixed)
• Output Current: 100mA
• Input Voltage Range: 10V to 35V
• Operating Temperature Range: -40°C to +125°C
• Package Type: TO-92 (through-hole)

Typical Applications 🔧

• Power management in consumer electronics
• Post-regulation for switching power supplies
• Chargers for small battery systems
• Standby power systems
• Creating a 5V rail for Arduino or other microcontroller projects, sensors, and electronics components

Design Notes and Tips 📝

• Ensure sufficient input-to-output headroom to maintain regulation; follow the device datasheet recommendations.
• Use proper decoupling: a typical guideline is ~0.33 µF on the input and ~0.1 µF on the output, placed close to the regulator pins.
• Consider thermal dissipation: power loss ≈ (Vin − 5V) × Iload. Add a heatsink or reduce input voltage if necessary.
• Ideal for low-current 5V rails in embedded systems; not suitable for powering a full Raspberry Pi board due to current limits.

Compatibility and Use Cases 🤖

Perfect for stepping down higher DC sources to a clean 5V for Arduino I/O, small modules (e.g., sensors, logic level devices), and other microcontroller-based circuits. A dependable choice when a simple, low-noise linear solution is preferred over switching regulators in sensitive analog or RF sections.