How to Select DC-DC Converters

What are DC-DC Converters?

DC-DC converters accept DC input and provide regulated and/or isolated DC output in various applications including computer flash memory, telecommunications equipment, and process control systems.

Selection Criteria

The GlobalSpec SpecSearch database allows industrial buyers to select DC-DC converters by product type, DC input, DC output, performance specifications, design options and features.

Product Types

Common converter styles include

• PCB mount
• PC board
• Internal or open frame mount power supplieshave exposed circuitry and components. They aresimply circuit boards to which all of the circuitry and components attach on one side.
• Rack mount come with hardware such as rail guides, flanges, or tabs. Some rack-mounted devices fit in a standard 19" telecommunications rack.
• DIN railare standard DIN rail mount. DIN is an acronym for Deutsches Institut für Normung (DIN), a German national organization for standardization.

DC Input

Choices for nominal DC input for DC-DC converters include 12 VDC, 24 VDC, 48 VDC, 110 VDC, 280 VDC, and 360 VDC.   

DC Output

DC output is the most important parameter to consider when searching for DC-DC converters.  Common outputs converted include 3.3V, 5V, 12V, 15V, 24V, and 48V. 

Performance Specifications

Other performance specifications to consider include

• Output power is measured by the wattage rating, which is the total nominal power output of a converter.
• Line regulation is the percent change in output voltage when VDC input is varied from lowest value to highest value.
• Load regulation is the maximum steady state amount that the output voltage changes as a result of a specified change in load.
• Minimum load is specified for the primary output for converter to meet performance specifications.

Design Options

• Common user interface options for DC-DC converters include
  • Analog front panel
  • Digital front panel
  • Computer interface
  • Parallel interface
  • Serial interface
• Application software may be included for control or monitoring.
• Display options include
  • Analog meter or indicators
  • Digital readouts
  • Video displays
• An important environmental parameter to consider when searching for DC-DC converters is the operating temperature.

Features

Common features for DC-DC converters include,

• Constant current supply (CC) designed to provide an output current that stays constant with changes in load impedance.
• Overvoltage protection is internal circuitry that limits or shuts down the voltage output in an overvoltage condition. When present, it is most usually found on the primary output.
• Overcurrent protection is internal circuitry that limits or shuts down the current output in an overcurrent condition.
• Short circuit protection employs techniques to protect the converter in the event of a short circuit on the load may include electronic current limiting and thermal resets with automatic recovery.
• Remote on and off converters have the option to turn the devices on or off remotely.

Applications

Used frequently on vehicle-mounted systems computer flash memory, telecommunication equipment and process control systems .  

• DC/DC Converters With Linear Regulators
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• DC-DC Converter Definitions
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• Hot-Plugggability And Turn On Delay In DC/DC Converters
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