DC-DC Power Supplies
A DC to DC power supply changes the voltage level of a direct current (DC) input supply to a DC output supply. The DC output voltage can be greater or less than the input.
DC-DC converters are electric power conversion circuits that generate a regulated voltage from an untamed source to varying loads. A DC-DC converter, as the name implies, only works with direct current (DC) sources and not with alternating current (AC).
A DC-DC converter is also called a voltage regulator or a DC-DC power converter. The output voltages of the converter are employed to match the power supply needed by the loads. A switch in the simple DC to DC converter circuit can control the connection and disconnection of the power supply to the load.
Quick links to DC-DC Power Supplies Information
How is DC-DC Power Generated?
DC-DC power supplies make use of the following steps:
- The current is passed through a switching element in a basic DC-DC converter.
- The DC-DC converter transforms the DC signal into an AC square wave signal.
- The AC square wave signal passes through a second filter.
- The second filter converts the signal to a DC signal with the requisite voltage.
Categories of DC-DC Power Supplies
DC-DC converters come in an array of designs. The most popular types are based on the voltage ratio between the input and output, including:
- Boost DC-DC Converters
- Raise the voltage to a higher level than the input voltage. A boost converter could be used to power a string of LEDs or generate a 5 V USB output from a lithium battery converter.
- Buck DC-DC Converters
- Reduce the input voltage to produce a lower output voltage. From a 5 V USB supply, a buck converter might be used to charge a lithium-ion battery to a 4.2 V converter.
- Buck-Boost Converters
- Steps a voltage up or down, resulting in a voltage that is equal to, higher than, or lower than the input voltage. To get a 12 V output from a 12 V battery, a buck-boost could be employed. The voltage of a 12V battery can range from 10 to 14.7 volts. A single cell might also be used to power an LED with a buck-boost converter. The forward drop of an LED can reach 3 V. The voltage of a lithium battery cell can range from 2.5 to 4.2 V. Buck boosts provide both positive and negative voltages.
- SEPIC Converters
- Can also step a voltage up or down, resulting in a voltage that is either equal to, higher than, or lower than the input voltage. A SEPIC is like a buck-boost in that it is used for similar applications, but it has certain other advantages.
Applications of a DC-DC Power Supply
DC-to-DC converters are widely used in portable electronic devices like cell phones and laptop computers that are powered primarily by batteries. Typical electronic devices include numerous sub-circuits, each with its own voltage level demand that differs from the battery and is sometimes higher or lower than the supply voltage. Additionally, as the battery's stored energy is depleted, the voltage drops. Instead of requiring many batteries to achieve the same result, switching DC to DC converters provides a way to raise the voltage from a partially decreased battery voltage, saving space.
The output voltage is usually regulated in most DC-to-DC converter circuits. High-efficiency LED power sources have simple charge pumps that double or triple the output voltage and DC to DC converters that manage the current via the LEDs.
Power optimizers are DC-to-DC converters that are used to optimize the energy harvest for solar systems and wind turbines. Furthermore, DC-DC techniques are used in places where a mains transformer could be employed, such as in residential electrical gadgets. In the context of varying voltage levels, DC-to-DC converters are also commonly utilized for DC microgrid applications.
Advantages of a DC-DC Converter
- It reduces the complexity of the circuit's power supply systems.
- It separates the major and minor circuits from one another.
- It offers a method for extending potential voltage as needed.
- It's accessible as a composite circuit that combines all the components into a single chip.
- It's utilized for DC voltage regulation.
- The output is properly sorted into positive and negative categories.
- Using a converter can help save battery space.