DC-DC converter is an electronic device that converts DC voltage into another DC voltage, widely used in power management, battery power supply systems, industrial control, automotive electronics and other fields. According to different classification criteria, DC-DC converters can be classified into the following categories:
1、 Classified by topological structure
Buck converter
Function: Reduce the input voltage to the desired output voltage.
Features: High efficiency, small output voltage ripple, suitable for scenarios that require stable low-voltage power supply.
Application: Power management for consumer electronic products such as smartphones, tablets, laptops, etc.
Boost converter
Function: Raise the input voltage to the desired output voltage.
Features: Suitable for scenarios where the input voltage is lower than the output voltage, such as solar panels, fuel cells, etc.
Applications: LED drivers, wireless sensor network nodes, etc.
Buck Boost converter
Function: The output voltage can be higher or lower than the input voltage, achieving bidirectional voltage conversion.
Features: High flexibility, suitable for scenarios with large input voltage fluctuations.
Applications: electric vehicles, renewable energy systems, etc.
Other topological structures
Cuk converter: Combining the characteristics of Buck and Boost converters, the output voltage has opposite polarity to the input voltage.
Sepic converter: The output voltage can be higher or lower than the input voltage, and the polarity of the input and output voltages is the same.
Zeta converter: Similar to Sepic converter, but with a different inductive connection method.
2、 Classified by control method
Pulse Width Modulation (PWM) Control
Principle: Control the output voltage by adjusting the conduction time (pulse width) of the switch tube.
Features: High efficiency, stable output voltage, suitable for most DC-DC converters.
Pulse frequency modulation (PFM) control
Principle: Control the output voltage by adjusting the switching frequency of the switch tube.
Characteristic: High efficiency under light load, but output voltage ripple may be large.
Hybrid modulation (PWM/PFM) control
Principle: Combining the advantages of PWM and PFM control, automatically switching control modes according to load conditions.
Characteristic: It can maintain high efficiency throughout the full load range.
3、 Classified by packaging form
Plug in packaging
Examples: TO-220, TO-263, etc.
Features: Good heat dissipation performance, suitable for high-power DC-DC converters.
Applications: industrial control, communication equipment, etc.
Surface mount packaging
Examples: SOT-23, SOIC, QFN, etc.
Features: Small size, suitable for miniaturization and high-density circuit boards.
Applications: consumer electronics, wearable devices, etc.
4、 Classified by application field
Consumer electronics
Characteristics: Requires small size, high efficiency, and low noise.
Applications: Smartphones, tablets, smartwatches, etc.
Industrial control category
Characteristics: High reliability, wide input voltage range, and strong anti-interference ability are required.
Applications: PLC, frequency converter, servo drive, etc.
Automotive Electronics
Characteristics: Requires high temperature resistance, vibration resistance, and a wide working temperature range.
Applications: Car chargers, ADAS systems, battery management systems, etc.
5、 Other classification methods
Isolation type and non isolation type
Isolation type DC-DC converter: Electrical isolation between input and output is achieved through transformers to improve safety.
Non isolated DC-DC converter: Direct connection between input and output, higher efficiency, but lower safety.
Synchronous rectification and asynchronous rectification
Synchronous rectification: Using MOSFETs instead of diodes for rectification to improve efficiency.
Non synchronous rectification: using diodes for rectification, with lower cost but lower efficiency.
6、 Selection suggestions
When choosing a DC-DC converter, the following factors need to be considered:
Input/output voltage range: Ensure that the converter can meet the voltage requirements of practical application scenarios.
Efficiency: High efficiency converters can reduce energy loss and improve overall system performance.
Cost: Choose the appropriate converter type based on the budget.
Size: Choose the appropriate packaging form based on the space of the circuit board.
Reliability: Choose high reliability converters in critical applications.
