Pololu 5V, 300mA Step-Down Voltage Regulator D24V3F5

The Pololu D24V3F5 is a compact buck (step-down) switching voltage regulator that converts input voltages up to 42 V down to a fixed 5 V output. With a typical efficiency of 80–90%, it significantly outperforms linear regulators like the 7805, especially when there is a large difference between input and output voltage.

The board features built-in short-circuit protection and thermal shutdown. Pins are spaced on a standard 0.1″ (2.54 mm) grid for easy use with breadboards and prototyping headers — a straight and right-angle header strip are both included.

Key Features

• Fixed 5 V Output – 4% accuracy, 300 mA maximum output current
• Wide Input Range – Accepts up to 42 V input (must exceed output voltage plus dropout)
• High Efficiency – 80–90% typical, far better than linear regulators
• 1.25 MHz Switching Frequency – Enables small external components
• Low Quiescent Current – 2 mA typical; 20 µA in shutdown mode
• Built-In Protection – Over-temperature and over-current shutoff
• Shutdown Pin – Drive SHDN low (under 0.3 V) to enter low-power mode, or tie to VIN to keep the regulator permanently enabled
• Compact Size – 13 × 10 × 3 mm

Connections

• SHDN – Shutdown control (active low). Drive low to disable output, high (>2.3 V) or tie to VIN to enable
• VIN – Input voltage (up to 42 V maximum)
• GND – Ground
• VOUT – Regulated 5 V output

Ideal For

• Battery-powered projects needing a stable 5 V supply
• Replacing inefficient 7805-style linear regulators
• Robotics, drones, and portable electronics with higher input voltages

Package Contents

• 1× Pololu D24V3F5 Step-Down Voltage Regulator
• 1× 4-pin straight male header strip
• 1× 4-pin right-angle male header strip

Resources

• Understanding Destructive LC Voltage Spikes (Pololu)