DC-DC Converter (buck/boost module)
Power
A circuit that converts one DC voltage level to another, either stepping down (buck) or stepping up (boost) the input voltage.
What it looks like
DC-DC Converter (buck/boost module)
A typical power — exact shape, colour and markings vary between manufacturers.
Types & variants
Key specs
Input voltage range
VMinimum to maximum DC voltage the converter can accept as input.
Output voltage
VFixed or adjustable DC voltage the converter provides.
Output current
AMaximum continuous current the converter can deliver.
Efficiency
%Ratio of output power to input power. Higher = less wasted energy as heat.
Switching frequency
kHzSpeed at which the converter switches. Higher frequencies allow smaller components but increase EMI.
Markings
Modules typically have silk-screen labels showing input/output voltage, current rating, model number, and polarity markings (+/-).
Standard values
Common input: 5V, 12V, 24V. Common output: 3.3V, 5V, 12V, 24V. Current ratings: 0.5A, 1A, 2A, 3A, 5A.
How to choose
1) Determine input voltage range. 2) Calculate required output voltage and current. 3) Select efficiency based on power needs (higher efficiency = less heat). 4) Consider switching frequency for EMI/noise requirements. 5) Check physical size and pinout compatibility.
Pinout & package
Typically 4 pins: Vin+, Vin-, Vout+, Vout-. Common packages: TO-220, DIP-8, SMD (e.g., TO-263, QFN). Always verify pinout as it varies by module.
Example circuits
- Powering a 5V microcontroller from a 12V battery
- Stepping up 3.3V from a coin cell to 5V for a sensor
- Creating a variable bench power supply with adjustable output
- Powering LEDs from a higher voltage source
Common failures
Failure to regulate output voltage, overheating (caused by overloading or poor heatsinking), input voltage outside specification, damaged output capacitors, or burnt components due to excessive current.
How to test
1) Apply input voltage within spec. 2) Measure output voltage with multimeter. Should match expected value. 3) Measure output current under load. Should not exceed rating. 4) Check for excessive heat during operation.
Substitutes
Different modules with same input/output specs. Custom-built converters using controller ICs and discrete components. Linear regulators (for simple step-down only, less efficient).