5.0V 250mA Linear Voltage Regulator - L4931-5.0 TO-92

The L4931-5.0 is a very-low-dropout (LDO) linear voltage regulator from STMicroelectronics, providing a clean 5V output with just 0.4V dropout — far better than the 7805's 2V dropout. It accepts 5.5–20V input and delivers up to 250mA continuous (300mA peak) in a compact TO-92 package.

Built-in current limiting and thermal shutdown protection make it robust for general-purpose use. The low 1mA quiescent current (rising to ~5mA at full load) makes it well-suited for battery-powered and portable projects.

Key Features

• Very Low Dropout – Only 0.4V (needs ≥5.4V input for clean 5V output)
• 2% Output Regulation – Clean, stable 5V supply
• Up to 300mA Peak – 250mA continuous with proper thermal management
• Built-in Protection – Current limiting and thermal shutdown
• Low Quiescent Current – 1mA typical, suitable for battery-powered projects
• TO-92 Package – Compact through-hole form factor

Specifications

• Output Voltage – 5.0 V (±2%)
• Input Voltage Range – 5.5–20 V
• Dropout Voltage – 0.4 V typical
• Max Output Current – 250 mA continuous, 300 mA peak
• Quiescent Current – 1 mA (up to 5 mA at full load)
• Package – TO-92
• Thermal Resistance – 200°C/W (junction-to-air, no heatsink)
• Max Power Dissipation – ~0.6 W (without heatsink)

Thermal Considerations

Power dissipation = (V_in − 5V) × I_out. Without a heatsink the TO-92 package can safely dissipate approximately 0.6W. For example:

• 9V input at 200mA = (9−5) × 0.2 = 0.8W — requires a heatsink or reduced current
• 6V input (4× AA) at 200mA = (6−5) × 0.2 = 0.2W — safe without a heatsink
• 9V input at 100mA = (9−5) × 0.1 = 0.4W — safe without a heatsink

Ideal For

• Regulating 9V batteries or 6V battery packs down to 5V
• Powering microcontrollers and 5V logic circuits
• Battery-powered and portable electronics

Package Contents

• 1× L4931-5.0 Voltage Regulator (TO-92)